Beta radiation-resistant elastomeric compositions, articles, and methods thereof

Abstract

A beta radiation-resistant elastomeric article of manufacture can include an elastomeric composition resistant to beta radiation. The elastomeric composition can include a polymer blend including a first copolymer and a second copolymer, carbon-carbon crosslinks between polymer chains of the polymer blend, and at least a conductive filler. The conductive filler is in a concentration sufficient to achieve its percolation point in the elastomeric composition, thereby forming a three-dimensional conductive network throughout the elastomeric composition. The conductive network is configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks, thereby, conferring resistance of the elastomeric article to the beta radiation. Such an elastomeric article can be made by mixing compounding ingredients of an elastomeric formulation in an internal mixer, discharging a nascent elastomeric composition from the internal mixer, and molding the article in a mold with heat, pressure or both to establish the carbon-carbon crosslinks and the conductive network therearound.

Description

BETA RADIATION-RESISTANT ELASTOMERIC COMPOSITIONS, ARTICLES,AND METHODS THEREOFBACKGROUND

[0001] Radioembolization is a medical procedure that involves injecting microspheres incorporating a radioactive isotope such as yttrium-90 directly into tumors by embolizing blood vessels that supply the tumors. This allows for high doses of short-range beta radiation to be delivered locally, specifically targeting the tumors without affecting healthy body tissue. In addition to the beta radiation, such radioactive microspheres also restrict blood flow to the tumors when embolizing the blood vessels that supply the tumors, thereby killing tumor cells by way of a concerted two-pronged mechanism.

[0002] Specialized medical devices are used to ensure the safety of clinicians performing radioembolization. Indeed, such medical devices are carefully engineered to minimize or eliminate clinician exposure to the beta radiation from the radioactive isotopes of microspheres. In this context, beta radiation-resistant elastomeric compositions, articles, and methods are provided for such medical devices.SUMMARY

[0003] Disclosed herein is a beta radiation-resistant elastomeric composition including, in some embodiments, a polymer blend including a first copolymer and a second copolymer; carbon-carbon crosslinks between polymer chains of the first copolymer, polymer chains of the second copolymer, the polymer chains of the first and second copolymers, or some combination thereof; and one or more fillers including at least a conductive filler in a concentration sufficient to achieve its percolation point in the elastomeric composition. The conductive filler forms a three-dimensional conductive network throughout the elastomeric composition. The conductive network is configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks, thereby, conferring resistance of the elastomeric composition to the beta radiation.

[0004] In some embodiments, the first copolymer is a brominated poly(isobutylene-co- isoprene) including one or more chemical moieties selected from allylic bromides, primary conjugated dienes derived from the allylic bromides, and primary Diels- Alder adducts derived from the primary conjugated dienes and one or more dienophiles. The primary Diels-Alderadducts are involved in at least a portion of the carbon-carbon crosslinks when the primary Diels-Alder adducts are formed between the polymer chains of the first copolymer, the polymer chains of the first and second copolymers, or some combination thereof.

[0005] In some embodiments, the one-or-more dienophiles are selected from 1,3- bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

[0006] In some embodiments, the second copolymer is a terpolymer derived from an ethylene monomer, a propylene monomer, and a diene monomer.

[0007] In some embodiments, the second copolymer includes residues of ethylidene norbornene (“ENB”), vinyl norbornene (“VNB”), or dicyclopentadiene (“DCPD”) corresponding to the diene monomer.

[0008] In some embodiments, the polymer blend further comprises a third copolymer. The carbon-carbon crosslinks are further between polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

[0009] In some embodiments, the third copolymer is a chlorinated poly(isobutylene- co-isoprene) including one or more chemical moi eties selected from allylic chlorides, secondary conjugated dienes derived from the allylic chlorides, and secondary Diels-Alder adducts derived from the secondary conjugated dienes and one or more electrophiles. The secondary Diels-Alder adducts are involved in at least a portion of the carbon-carbon crosslinks when the secondary Diels-Alder adducts are formed between the polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

[0010] In some embodiments, the one-or-more electrophiles are selected from 1,3- bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

[0011] In some embodiments, at least a portion of the carbon-carbon crosslinks include an alkyl -substituted phenol-formaldehyde resin crosslinking one or more copolymers of the polymer blend by way of tetrahydropyran adducts.

[0012] In some embodiments, the one-or-more fillers further include a magnesium silicate and a zeolite as a reinforcing filler. At least a portion of the zeolite is spent zeolite remaining in the elastomeric composition after curing the elastomeric composition to establish the carbon-carbon crosslinks from the alkyl-substituted phenol-formaldehyde resin.

[0013] In some embodiments, the one-or-more fillers further include an antioxidant as a stabilizing filler.

[0014] In some embodiments, the conductive filler includes a carbon allotrope having a graphitic content of at least 40% by weight of the carbon allotrope.

[0015] In some embodiments, the elastomeric composition has a Shore-A durometer of 40-55; a tensile strength of 3.4-6.2 MPa both before and after a dose of beta radiation up to 80 kGy, the tensile strength before the dose of beta radiation being greater than that after the dose of beta radiation; and an elongation at break of 425 -725 both before and after the dose of beta radiation up to 80 kGy, the elongation at break before the dose of beta radiation being greater than that after the dose of beta radiation.

[0016] Also disclosed herein is a beta radiation-resistant elastomeric article of manufacture including, in some embodiments, an elastomeric composition resistant to beta radiation. The elastomeric composition includes a polymer blend including a first copolymer and a second copolymer; carbon-carbon crosslinks between polymer chains of the first copolymer, polymer chains of the second copolymer, the polymer chains of the first and second copolymers, or some combination thereof; and one or more fillers including at least a conductive filler in a concentration sufficient to achieve its percolation point in the elastomeric composition. The conductive filler forms a three-dimensional conductive network throughout the elastomeric composition. The conductive network is configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks, thereby, conferring resistance of the elastomeric article to the beta radiation.

[0017] In some embodiments, the first copolymer is a brominated poly(isobutylene-co- isoprene) including one or more chemical moieties selected from allylic bromides, primary conjugated dienes derived from the allylic bromides, and primary Diels- Alder adducts derived from the primary conjugated dienes and one or more dienophiles. The primary Diels-Alder adducts are involved in at least a portion of the carbon-carbon crosslinks when the primaryDiels-Alder adducts are formed between the polymer chains of the first copolymer, the polymer chains of the first and second copolymers, or some combination thereof.

[0018] In some embodiments, the one-or-more dienophiles are selected from 1,3- bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

[0019] In some embodiments, the second copolymer is a terpolymer derived from an ethylene monomer, a propylene monomer, and a diene monomer.

[0020] In some embodiments, the second copolymer includes residues of ENB, VNB, or DCPD corresponding to the diene monomer.

[0021] In some embodiments, the polymer blend further comprises a third copolymer. The carbon-carbon crosslinks are further between polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

[0022] In some embodiments, the third copolymer is a chlorinated poly(isobutylene- co-isoprene) including one or more chemical moi eties selected from allylic chlorides, secondary conjugated dienes derived from the allylic chlorides, and secondary Diels-Alder adducts derived from the secondary conjugated dienes and one or more electrophiles. The secondary Diels-Alder adducts are involved in at least a portion of the carbon-carbon crosslinks when the secondary Diels-Alder adducts are formed between the polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

[0023] In some embodiments, the one-or-more electrophiles are selected from 1,3- bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

[0024] In some embodiments, at least a portion of the carbon-carbon crosslinks include an alkyl-substituted phenol-formaldehyde resin one or more copolymers of the polymer blend by way of tetrahydropyran adducts.

[0025] In some embodiments, the one-or-more fillers further include a magnesium silicate and a zeolite as a reinforcing filler. At least a portion of the zeolite is spent zeoliteremaining in the elastomeric composition after curing the elastomeric composition to establish the carbon-carbon crosslinks from the alkyl-substituted phenol-formaldehyde resin.

[0026] In some embodiments, the one-or-more fillers further include an antioxidant as a stabilizing filler.

[0027] In some embodiments, the conductive filler includes a carbon allotrope having a graphitic content of at least 40% by weight of the carbon allotrope.

[0028] In some embodiments, the elastomeric article is a septum molded from the elastomeric composition.

[0029] In some embodiments, the septum has a Shore-A durometer of 40-55; a tensile strength of 3.4-6.2 MPa both before and after a dose of beta radiation up to 80 kGy, the tensile strength before the dose of beta radiation being greater than that after the dose of beta radiation; and an elongation at break of 425 -725 both before and after the dose of beta radiation up to 80 kGy, the elongation at break before the dose of beta radiation being greater than that after the dose of beta radiation.

[0030] Also disclosed herein is a method of making a beta radiation-resistant elastomeric article of manufacture. The method includes, in some embodiments, one or more loading operations, one or more mixing operations, a discharging operation, a molding operation, and a curing operation. The one-or-more loading operations include loading compounding ingredients of an elastomeric formulation into an internal mixer. The compounding ingredients include a first copolymer, a second copolymer, one or more crosslinking agents, and one or more fillers including a conductive filler. The mixing operation includes mixing the compounding ingredients in the internal mixer. The discharging operation includes discharging a nascent elastomeric composition from the internal mixer in a continuous sheet-like form. The molding operation includes molding the nascent elastomeric composition into the elastomeric article in a compression mold. The curing operation includes applying heat, pressure, or both to the compression mold to establish or complete crosslinking in a final elastomeric composition of the elastomeric article. The final elastomeric composition includes a polymer blend including the first copolymer and the second copolymer; carbon-carbon crosslinks between polymer chains of the polymer blend; and one or more fillers including at least the conductive filler in a concentration sufficient to achieve its percolation point in the final elastomeric composition. The conductive filler forms a three-dimensional conductivenetwork throughout the final elastomeric composition. The conductive network is configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks, thereby, conferring resistance of the elastomeric article to the beta radiation.

[0031] These and other features of the concepts provided herein will become more apparent to those of skill in the art in view of the accompanying drawings and following description, which describe particular embodiments of such concepts in greater detail.DRAWINGS

[0032] FIG. 1 illustrates a beta radiation-resistant elastomeric composition in accordance with some embodiments.

[0033] FIG. 2A illustrates sites of unsaturation in at least a first copolymer of the elastomeric composition in accordance with some embodiments.

[0034] FIG. 2B illustrates sites of unsaturation in a second copolymer of the elastomeric composition in accordance with some embodiments.

[0035] FIG. 3A illustrates pendant crosslinkers and crosslinks between some of the sites of unsaturation in at least the first and second copolymers of the elastomeric composition in accordance with some embodiments.

[0036] FIG. 3B illustrates additional pendant crosslinkers and crosslinks between some of the sites of unsaturation in at least the first and second copolymers of the elastomeric composition in accordance with some embodiments.

[0037] FIG. 4 illustrates a side view of a vial assembly of a delivery device for administering radioactive microspheres in accordance with some embodiments.

[0038] FIG. 5 illustrates an exploded view of the vial assembly including a vial body, a septum of the elastomeric composition, and a septum cap in accordance with some embodiments.

[0039] FIG. 6 illustrates a longitudinal cross-section of the vial assembly including the vial body, the septum, and the septum cap in accordance with some embodiments.

[0040] FIG. 7 illustrates a detailed view of a septum-sealed end portion of the vial assembly including the vial body, the septum, and the septum cap in accordance with some embodiments.

[0041] FIG. 8 illustrates a perspective view of a septum cap-facing face of the septum in accordance with some embodiments.

[0042] FIG. 9 illustrates a side view of the septum in accordance with some embodiments.

[0043] FIG. 10 illustrates a view of the septum cap-facing face of the septum in accordance with some embodiments.

[0044] FIG. 11 illustrates a diametrical cross-section of the septum in accordance with some embodiments.DESCRIPTION

[0045] Before some particular embodiments are disclosed in greater detail, it should be understood that the particular embodiments disclosed herein do not limit the scope of the concepts provided herein. It should also be understood that a particular embodiment disclosed herein can have features that can be readily separated from the particular embodiment and optionally combined with or substituted for features of any of a number of other embodiments disclosed herein.

[0046] Regarding terms used herein, it should also be understood the terms are for the purpose of describing some particular embodiments, and the terms do not limit the scope of the concepts provided herein.

[0047] Ordinal numbers (e.g., first, second, third, etc.) are generally used to distinguish or uniquely identify different features or steps in a group of features or steps, and do not supply a serial or numerical limitation. For example, “first,” “second,” and “third” features or steps need not necessarily appear in that order, and the particular embodiments including such features or steps need not necessarily be limited to the three features or steps. In addition, any of the foregoing features or steps can, in turn, further include one or more features or steps unless indicated otherwise.

[0048] Likewise, “primary,” “secondary,” “tertiary,” etc., can be used to distinguish or uniquely identify different features or steps in a group of features or steps; however, when “primary,” “secondary,” “tertiary,” etc., are used to distinguish or uniquely identify chemical moieties, they should not be construed in terms of their meaning in chemistry, if any. For example, “primary,” as in “primary conjugated dienes” derived from allylic bromides and “primary Diels-Alder adducts” derived from the primary conjugated dienes, and “secondary,” as in “secondary conjugated dienes” derived from allylic chlorides and “secondary Diels- Alder adducts” derived from the secondary conjugated dienes, are used to distinguish or uniquely identify the conjugated dienes derived from the allylic bromides and the conjugated dienes derived from the allylic chlorides, as well as the Diels-Alder adducts therefrom. In such instances, “primary” and “secondary” are not used to indicate, for example, a degree of substitution of any carbon atoms to which the “primary conjugated dienes,” “primary Diels- Alder adducts,” “secondary conjugated dienes,” or “secondary Diels-Alder adducts” are bonded.

[0049] Labels such as “left,” “right,” “top,” “bottom,” “front,” “back,” and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. Instead, such labels are used to reflect, for example, relative location, orientation, or directions.

[0050] Lastly, singular forms of “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.

[0051] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art.

[0052] As set forth above, radioembolization is a medical procedure that involves injecting microspheres incorporating a radioactive isotope such as yttrium-90 directly into tumors by embolizing blood vessels that supply the tumors. This allows for high doses of short- range beta radiation to be delivered locally, specifically targeting the tumors without affecting healthy body tissue. In addition to the beta radiation, such radioactive microspheres also restrict blood flow to the tumors when embolizing the blood vessels that supply the tumors, thereby killing tumor cells by way of a concerted two-pronged mechanism.

[0053] Specialized medical devices are used to ensure the safety of clinicians performing radioembolization. Indeed, such medical devices are carefully engineered tominimize or eliminate clinician exposure to the beta radiation from the radioactive isotopes of microspheres. In this context, beta radiation-resistant elastomeric compositions, articles, and methods are provided for such medical devices.

[0054] For example, a beta radiation-resistant elastomeric composition can include a polymer blend including a first copolymer and a second copolymer, carbon-carbon crosslinks between polymer chains of the polymer blend, and at least a conductive filler in a concentration sufficient to achieve its percolation point in the elastomeric composition. The conductive filler forms a three-dimensional conductive network throughout the elastomeric composition. The conductive network is configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks, thereby, conferring resistance of the elastomeric article to the beta radiation. Such an elastomeric article can be made by mixing compounding ingredients of an elastomeric formulation in an internal mixer, discharging a nascent elastomeric composition from the internal mixer, and molding the article in a mold with heat, pressure or both to establish the carbon-carbon crosslinks and the conductive network therearound.Beta radiation-resistant elastomeric composition

[0055] FIG. 1 illustrates a beta radiation-resistant elastomeric composition in accordance with some embodiments.

[0056] As shown, the elastomeric composition can include a polymer blend of two or more copolymers, carbon-carbon crosslinks between polymer chains of the polymer blend, and one or more fillers including at least a conductive filler forming a three-dimensional conductive network throughout the elastomeric composition. The conductive network is configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks, thereby, conferring resistance of the elastomeric composition to the beta radiation.

[0057] The two-or-more copolymers of the polymer blend can be selected from a halogenated poly(isobutylene-co-isoprene) or “halobutyl” copolymer and a terpolymer derived from an ethylene monomer, a propylene monomer, and a diene monomer, which is sometimes referred to as an “EPDM” terpolymer in reference to the ethylene, propylene, and diene monomers from which the terpolymer is derived. The halobutyl copolymer can be selected from a brominated poly(isobutylene-co-isoprene) or “bromobutyl” copolymer and achlorinated poly(isobutylene-co-isoprene) or “chlorobutyl” copolymer. The EPDM terpolymer can be selected from an EPDM terpolymer including ENB residues, an EPDM terpolymer including VNB residues, and an EPDM terpolymer including DCPD residues, the ENB, VNB, and DCPD residues corresponding to the diene monomer. In an example, the two-or-more copolymers of the polymer blend can include the bromobutyl copolymer for a first copolymer and the EPDM terpolymer for a second polymer. In another example, the two-or-more copolymers of the polymer blend can include the bromobutyl copolymer for the first copolymer, the EPDM terpolymer for the second polymer, and the chlorobutyl copolymer for a third copolymer, wherein the EPDM terpolymer has the ENB residues.

[0058] FIGS. 2 A and 2B illustrate sites of unsaturation in the two-or-more copolymers of the polymer blend in accordance with some embodiments. FIGS. 3A and 3B illustrate pendant crosslinkers and crosslinks between some of the sites of unsaturation in the two-or- more copolymers of the polymer blend in accordance with some embodiments.

[0059] As to the brominated poly(isobutylene-co-isoprene) or bromobutyl copolymer, which, again, can be the first copolymer of the polymer blend, the bromobutyl copolymer can include one or more chemical moieties selected from the sites of unsaturation including isolated carbon-carbon double bonds, allylic bromides, conjugated dienes derived from the allylic bromides, or some combination thereof, Diels-Alder adducts derived from the conjugated dienes and one or more electrophiles or dienophiles such as 1,3- bis(citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol, and tetrahydropyran adducts derived from the sites of unsaturation and the alkyl-substituted phenolformaldehyde resin set forth below. Notably, adducts of the Diels-Alder and tetrahydropyran adducts not involved in the carbon-carbon crosslinks can be portions of pendant crosslinkers extending from the polymer chains of the bromobutyl copolymer, the pendant crosslinkers derived from the sites of unsaturation and one or more crosslinking agents selected from 1,3- bis(citraconimidomethyl)benzene, 1,3-bis (citraconimidomethyl)benzol, and the alkylsubstituted phenol-formaldehyde resin set forth below.

[0060] As to the EPDM terpolymer, which, again, can be the second copolymer of the polymer blend, the EPDM terpolymer can include one or more chemical moieties selected from the sites of unsaturation including isolated carbon-carbon double bonds and tetrahydropyran adducts derived from the sites of unsaturation and the alkyl-substituted phenol-formaldehyde resin set forth below. Notably, adducts of the tetrahydropyran adducts not involved in thecarbon-carbon crosslinks can be portions of pendant crosslinkers extending from the polymer chains of the EPDM terpolymer, the pendant crosslinkers derived from the sites of unsaturation and the alkyl-substituted phenol-formaldehyde resin set forth below as the crosslinking agent.

[0061] As to the chlorinated poly(isobutylene-co-isoprene) or chlorobutyl copolymer, which, again, can be the third copolymer of the polymer blend, the chlorobutyl copolymer can include one or more chemical moieties selected from the sites of unsaturation including isolated carbon-carbon double bonds, allylic chlorides, conjugated dienes derived from the allylic chlorides, or some combination thereof, Diels-Alder adducts derived from the conjugated dienes and the one-or-more electrophiles or dienophiles such as 1,3- bis(citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol, and tetrahydropyran adducts derived from the sites of unsaturation and the alkyl-substituted phenolformaldehyde resin set forth below. Notably, adducts of the Diels-Alder and tetrahydropyran adducts not involved in the carbon-carbon crosslinks can be portions of pendant crosslinkers extending from the polymer chains of the chlorobutyl copolymer, the pendant crosslinkers derived from the sites of unsaturation and the one-or-more crosslinking agents selected from l,3-bis(citraconimidomethyl)benzene, 1,3-bis (citraconimidomethyl)benzol, and the alkyl- substituted phenol-formaldehyde resin set forth below.

[0062] The carbon-carbon crosslinks between the polymer chains of the polymer blend, the carbon-carbon crosslinks can be between polymer chains of the brominated poly(isobutylene-co-isoprene) or bromobutyl copolymer as the first copolymer, polymer chains of the EPDM terpolymer as the second copolymer, the polymer chains of the bromobutyl copolymer and the EPDM terpolymer, or some combination thereof. When the chlorinated poly(isobutylene-co-isoprene) or chlorobutyl copolymer is present as the third copolymer in the polymer blend, the carbon-carbon crosslinks can be further between polymer chains of the chlorobutyl copolymer, the polymer chains of the bromobutyl copolymer and the chlorobutyl copolymer, the polymer chains of the EPDM terpolymer and the chlorobutyl copolymer, the polymer chains of the bromobutyl copolymer, the EPDM terpolymer, and the chlorobutyl copolymer, or some combination thereof.

[0063] Further to the carbon-carbon crosslinks between the polymer chains of the polymer blend, at least a portion of the carbon-carbon crosslinks can include an alkyl- substituted phenol-formaldehyde resin, which is sometimes referred to as a resole resin, crosslinking the polymer chains of the polymer blend by way of terminal tetrahydropyranadducts as shown in FIG. 3A. Such an alkyl-substituted phenol-formaldehyde resin can be an octyl-substituted phenol-formaldehyde resin. Another portion of the carbon-carbon crosslinks can also include l,3-bis(citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol crosslinking the polymer chains of the polymer blend by way of terminal Diels-Alder adducts as shown in FIG. 3B. Each copolymer of the brominated poly(isobutylene-co-isoprene) or bromobutyl copolymer, the EPDM terpolymer, and the chlorinated poly(isobutylene-co- isoprene) or chlorobutyl copolymer includes the isolated carbon-carbon double bonds among its sites of unsaturation at least before being crosslinked, so each copolymer of the bromobutyl copolymer, the EPDM terpolymer, and the chlorobutyl copolymer can include the tetrahydropyran adducts formed between its polymer chains and the alkyl-substituted phenolformaldehyde resin in accordance with the carbon-carbon crosslinks between the polymer chains of the polymer blend set forth above. Each copolymer of the bromobutyl copolymer and the chlorobutyl copolymer also includes the conjugated dienes or an allylic halide precursor thereto among its sites of unsaturation at least before being crosslinked, so each copolymer of the bromobutyl copolymer and the chlorobutyl copolymer can include the Diels-Alder adducts formed between its polymer chains and the l,3-bis(citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol in accordance with the carbon-carbon crosslinks between the polymer chains of the polymer blend set forth above. However, the EPDM terpolymer does not include conjugated dienes among its sites of unsaturation or a chemical moiety such as the allylic halide that forms the conjugated dienes under conditions set forth below for making the elastomeric composition, so the EPDM does not include the Diels-Alder adducts formed between its polymer chains and the l,3-bis(citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol or any of the carbon-carbon crosslinks associated therewith.

[0064] Again, the one-or-more fillers can include at least the conductive filler forming a three-dimensional conductive network throughout the elastomeric composition. The conductive network is configured to conduct the beta radiation away from the carbon-carbon crosslinks as shown in FIG. 1 for maintaining the integrity of the carbon-carbon crosslinks, thereby, conferring resistance of the elastomeric composition to the beta radiation. Such a conductive filler can include a carbon allotrope having a graphitic content of at least 40% by weight of the carbon allotrope including, but not limited to, a carbon black or carbon-black mixture selected from acetylene black, channel black, furnace black, lamp black, and thermal black. Additionally or alternatively, the carbon allotrope can include graphene, a fullerene suchas a closed fullerene C„ (e.g., Ceo) or a carbon nanotube, or a mixture of fullerenes such as fullerite. For example, the conductive filler can be acetylene black.

[0065] Whether the conductive filler is a carbon black, a carbon-black mixture, graphene, a fullerene, fullerite, or some combination thereof, the conductive filler can be in a concentration sufficient to achieve its percolation point in the elastomeric composition. The conductive filler can be at least 6%, 12%, 22%, 27%, 32%, 37%, 42%, 47%, 52%, 57%, or 60% by weight of the elastomeric composition, inclusive of any intervening concentrations defined by the so-called ones or units place. Alternatively, the conductive filler can be no more than 60%, 57%, 52%, 47%, 42%, 37%, 32%, 27%, 22%, 12%, or 6% by weight of the elastomeric composition, inclusive of any intervening concentrations defined by the so-called ones or units place. As such, the concentration of the conductive filler in the elastomeric composition can be at least 6% by weight and no more than 60% by weight, including at least 12% by weight and no more than 57% by weight, such as at least 22% by weight and no more than 52% by weight, for example, at least 27% by weight and no more than 47% by weight. For example, the conductive filler can be at least 6.3% by weight in the elastomeric composition.

[0066] The one-or-more fillers can also include one or more reinforcing fillers complementing the conductive filler in its function as a reinforcing filler, thereby enhancing certain properties to the elastomeric composition. The one-or-more reinforcing fillers can be silicate fillers selected from silica, sodium silicate, potassium silicate, calcium silicate, magnesium silicate, and aluminum silicate. For example, the one-or-more reinforcing fillers can include magnesium silicate. However, it should be understood the one-or-more reinforcing filler are not limited to silicate fillers. Notably, the one-or-more reinforcing fillers can also include spent zeolite remaining in the elastomeric composition after curing the elastomeric formulation.

[0067] The one-or-more fillers can also include one or more stabilizing fillers such as antioxidants or radical scavengers for scavenging radicals in the elastomeric composition resulting from the beta radiation. The one-or-more stabilizing fillers can be selected from butylated hydroxytoluene (“BHT”), butylated hydroxyanisole (“BHA”), and butylated hydroxyquinone (“BHQ”). For example, the one-or-more stabilizing fillers can include BHT.

[0068] Notably, it is advantageous for the one-or-more fillers to include filler materials formed of elements or their ions having lower atomic numbers for better beta-radiation shielding and reduced bremsstrahlung. The elements or ions of such filler materials can include elements or ions selected from fluorine, chlorine, phosphorous, silicon, aluminum, and magnesium.

[0069] Such an elastomeric composition can have a Shore-A durometer of 40-55; a tensile strength of 3.4-6.2 MPa both before and after a dose of beta radiation up to 80 kGy, the tensile strength before the dose of beta radiation being greater than that after the dose of beta radiation; and an elongation at break of 425 -725 both before and after the dose of beta radiation up to 80 kGy, the elongation at break before the dose of beta radiation being greater than that after the dose of beta radiation, as set forth in Table 1 below.Table 1 : Examples of the elastomeric formulation and certain properties.Beta radiation-resistant elastomeric article of manufacture

[0070] FIGS. 4-7 illustrate a vial assembly 100 of a delivery device for administering radioactive microspheres 102 in accordance with some embodiments. An example of such a delivery device is delivery device 500 in FIG. 13 of US 2021 / 0369946, which is incorporated by reference in its entirety into this application.

[0071] As shown, the vial assembly 100 can include a cylindrical vial body 104, a diskshaped septum 106 of the elastomeric composition, and a disk-shaped septum cap 108; however, other shapes, geometries, or the like are possible for the vial body 104, the septum 106, and the septum cap 108 depending upon the delivery device. Notably, FIG. 7 illustrates a detailed view of a septum-sealed end portion of the vial assembly 100, wherein at least the septum cap 108 is fixedly attached to the vial body 104. Indeed, at least a vial body -facing annular portion 110 of the septum cap 108 can be fixedly attached by a heat weld, a solvent weld, or the like to a septum cap-facing annular recess 112 in a septum-sealable end portion of the vial body 104. In addition, an optional circumferential ridge 114 about the annular portion 110 of the septum cap 108 can be fixedly attached by the heat weld, the solvent weld, or the like to a corresponding circumferential channel in the annular recess 112 of the of the vial body 104 to further secure the septum cap 108 to the vial body 104. The septum 106 can be compressed between the septum cap 108 and the vial body 104 and, optionally, fixedly attached to the septum cap 108, the vial body 104, or both the septum cap 108 and the vial body 104 such that the boss 116 of the septum 106 covers an orifice 118 in the septum-sealable end portion of the vial body 104.

[0072] FIGS. 8-11 illustrate the septum 106 in accordance with some embodiments.

[0073] As shown, the septum can include a boss 116 extending from a vial body-facing portion of a body 120 of the septum 106, wherein the boss 116 is configured to cover the orifice 118 of the of the vial body 104. A remainder of the vial body-facing portion of the body 120 of the septum 106, in particular, an annular portion 122 around the boss 116, can be fixedly attached by a heat weld, a solvent weld, or the like to a septum-facing annular recess recessed within the septum cap-facing annular recess 112 in the septum-sealable end portion of the vial body 104 to secure the septum 106 to the vial body 104 if the septum 106 is not merely compressed between the septum cap 108 and the vial body 104. Similar to the septum cap 108, the annular portion 122 of the septum 106 can optionally include circumferential ridges 124 encircling the boss 116 about the annular portion 122 of the septum 106, which circumferential ridges 124 can be fixedly attached by the heat weld, the solvent weld, or the like to corresponding circumferential channels in the septum-facing annular recess of the vial body 104 to further secure the septum cap 108 to the vial body 104. Notably, a septum cap-facing portion of the body 120 of the septum 106 can likewise include circumferential ridges 126. Such circumferential ridges 126 can be fixedly attached to the vial body -facing annular portion 110 of the septum cap 108 by way of by a heat weld, a solvent weld, or the like if the septum 106 is not merely compressed between the septum cap 108 and the vial body 104. Regardless, both the circumferential ridges 124 and 126 are configured to enhance compressibility of the septum 106 between the septum cap 108 and the vial body 104 in that, when the septum 106 is compressed, annular spaces between the circumferential ridges 124 and 126 allow elastomeric material of the circumferential ridges 124 and 126 to radially expand into the annular spaces unencumbered by the elastomeric material that would otherwise be between the circumferential ridges 124 and 126.

[0074] As alluded to in FIG. 7, the septum 106 allows the vial assembly 100 to be safely accessed by a needle for both loading a dose of the radioactive microspheres 102 into the vial assembly 100 and administering the dose of the radioactive microspheres 102 from the vial assembly 100. Notably, such loading and administering of the dose the radioactive microspheres 102 is performed with at least the delivery device 500 in FIG. 13 of US 2021 / 0369946, which is incorporated by reference in its entirety into this application.

[0075] It should be understood that the septum is but one example of the elastomeric article, and the elastomeric article should not be limited thereto. Indeed, the nascent elastomeric composition set forth below in the method of making the elastomeric article can be molded intoany of a number of different elastomeric articles for the specialized medical devices used in radioembolization procedures. In fact, the nascent elastomeric composition can be molded into any of a number of different elastomeric articles that benefit from resistance to beta radiation regardless of their association with radioembolization.

[0076] Notably, like the elastomeric composition itself, the septum 106 or any other elastomeric article molded from the elastomeric composition, has a Shore-A durometer of 40- 55; a tensile strength of 3.4-6.2 MPa both before and after a dose of beta radiation up to 80 kGy, the tensile strength before the dose of beta radiation being greater than that after the dose of beta radiation; and an elongation at break of 425 -725 both before and after the dose of beta radiation up to 80 kGy, the elongation at break before the dose of beta radiation being greater than that after the dose of beta radiation. Further, the septum 106 and other elastomeric articles molded from the elastomeric composition can have enhanced resistance to aging, permeability, and mechanical puncture while having enhanced sealability.Methods

[0077] Methods include methods of making the elastomeric composition, the elastomeric article, or both the elastomeric composition and the elastomeric article. For example, a method of making the elastomeric article can include one or more operations selected from a weighing operation, a loading operation, a mixing operation, a discharging operation, a molding operation, and a curing operation, each operation of which can include additional operations or suboperations. For example, the loading operation can include an initial loading operation and one or more additional loading operations, as needed, for loading different compounding ingredients. Further, the mixing operation can include an initial mixing operation and one or more additional mixing operations, as needed, for mixing the compounding ingredients under different conditions. Such loading and mixing operations can be varied, as needed, to achieve certain properties of the elastomeric composition.

[0078] The weighing operation can include weighing the compounding ingredients in accordance with an elastomeric formulation for the elastomeric composition, and, optionally, pre-mixing two or more of the compounding ingredients to partially blend them or facilitate their addition to an internal mixer of a Banbury machine through one or more input ports thereof. The weighing of the compounding ingredients can be in parts-per-hundred rubber (“phr”), as set forth in detail below with respect to the compounding ingredients of the elastomeric formulation.

[0079] As to the elastomeric formulation for the elastomeric composition, the compounding ingredients can be selected from the two-or-more copolymers, the one-or-more crosslinking agents, the one-or-more fillers, and one or more additives, wherein the elastomeric formulation includes at least the two-or-more copolymers. While such compounding ingredients are set forth in detail below in accordance with their identities or functions as copolymers, crosslinking agents, fillers, and additives, it should be understood that some compounding ingredients can have more than one identity or function. In an example, the zeolite curative, or at least the spent zeolite remaining in the elastomeric composition after curing the elastomeric formulation, can also be a reinforcing filler. In another example, the ZnO catalyst, or at least ZnO remaining in the elastomeric composition after catalyzing formation of the conjugated dienes from the allylic bromides or allylic chlorides, can also be an acid scavenger. Likewise, albeit inversely, the MgO acid scavenger can also be a catalyst for forming the conjugated dienes from the allylic bromides or allylic chlorides.

[0080] The two-or-more copolymers can be selected from the halogenated poly(isobutylene-co-isoprene) or halobutyl copolymer and the EPDM terpolymer, wherein the halobutyl copolymer is selected from the bromobutyl copolymer and the chlorobutyl copolymer, and wherein the EPDM terpolymer includes ENB, VNB, or DCPD residues. For example, the two-or-more copolymers can include the bromobutyl copolymer and the EPDM terpolymer or the bromobutyl copolymer, the chlorobutyl copolymer, and the EPDM terpolymer, wherein the EPDM terpolymer has the ENB residues.

[0081] As to the brominated poly(isobutylene-co-isoprene) or bromobutyl copolymer (e.g., X_Butyl® BB X2, Arlanxeo), the bromobutyl copolymer can be at least 50, 55, 60, 65, 70, 75, 80, 85, or 90 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. Alternatively, the bromobutyl copolymer can be no more than 90, 85, 80, 75, 70, 65, 60, 65, or 60 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. As such, the concentration of the bromobutyl copolymer in the elastomeric formulation can be at least 50 phr and no more than 90 phr, including at least 55 phr and no more than 85 phr, such as at least 60 phr and no more than 80 phr, for example, at least 65 phr and no more than 75 phr.

[0082] As to the chlorinated poly(isobutylene-co-isoprene) or chlorobutyl copolymer (e.g., X_Butyl® CB 1240, Arlanxeo), the chlorobutyl copolymer can be at least 1, 5, 10, 15,20, 25, or 30 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. Alternatively, the chlorobutyl copolymer can be no more than 30, 25, 20, 15, 10, 5, or 1 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. As such, the concentration of the chlorobutyl copolymer in the elastomeric formulation can be at least 1 phr and no more than 30 phr, including at least 5 phr and no more than 25 phr, such as at least 10 phr and no more than 20 phr, for example, at least 15 phr and no more than 20 phr.

[0083] With both the brominated poly(isobutylene-co-isoprene) or bromobutyl copolymer and the chlorinated poly(isobutylene-co-isoprene) or chlorobutyl copolymer present in the elastomeric formulation, a ratio of the bromobutyl copolymer to the chlorobutyl copolymer can be at least 2.0 to 1.0, 3.0 to 1.0, 4.0 to 1.0, 5.0 to 1.0, 6.0 to 1.0, 7.0 to 1.0, or 8.0 to 1.0, inclusive of any intervening ratios defined by the so-called tenths place. Alternatively, the ratio of the bromobutyl copolymer to the chlorobutyl copolymer can be no more than 8.0 to 1.0, 7.0 to 1.0, 6.0 to 1.0, 5.0 to 1.0, 4.0 to 1.0, 3.0 to 1.0, or 2.0 to 1.0, inclusive of any intervening ratios defined by the so-called tenths place. As such, the ratio of the bromobutyl copolymer to the chlorobutyl copolymer can be at least 2.0 and no more than 8.0, including at least 3.0 and no more than 7.0, such as at least 4.0 and no more than 6.0, for example, at least 5.0 and no more than 6.0.

[0084] As to the EPDM terpolymer (e.g., Keltan® 2650, Arlanxeo), the EPDM terpolymer can be at least 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. Alternatively, the EPDM terpolymer copolymer can be no more than 50, 55, 40, 35, 30,25, 20, 15, 10, 5, or 1 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. As such, the concentration of the EPDM terpolymer in the elastomeric formulation can be at least 1 phr and no more than 50 phr, including at least 5 phr and no more than 45 phr, such as at least 10 phr and no more than 40 phr, for example, at least 15 phr and no more than 35 phr.

[0085] Whether the brominated poly(isobutylene-co-isoprene) or bromobutyl copolymer, the chlorinated poly(isobutylene-co-isoprene) or chlorobutyl copolymer, or both the bromobutyl and chlorobutyl copolymers are present in the elastomeric formulation, a ratio of the halobutyl copolymer to the EPDM terpolymer can be at least 1.0 to 1.0, 2.0 to 1.0, 3.0 to 1.0, 4.0 to 1.0, 5.0 to 1.0, 6.0 to 1.0, 7.0 to 1.0, 8.0 to 1.0, 9.0 to 1.0, or 10.0 to 1.0 inclusiveof any intervening ratios defined by the so-called tenths place. Alternatively, the ratio of the halobutyl copolymer to the EPDM terpolymer can be no more than 10.0 to 1.0, 9.0 to 1.0, 8.0 to 1.0, 7.0 to 1.0, 6.0 to 1.0, 5.0 to 1.0, 4.0 to 1.0, 3.0 to 1.0, 2.0 to 1.0, or 1.0 to 1.0, inclusive of any intervening ratios defined by the so-called tenths place. As such, the ratio of the halobutyl copolymer to the EPDM terpolymer can be at least 1.0 and no more than 10.0, including at least 2.0 and no more than 9.0, such as at least 3.0 and no more than 8.0, for example, at least 4.0 and no more than 7.0.

[0086] The one-or-more crosslinking agents can be carbon-carbon crosslinking agents selected from a halogenated alkyl-substituted phenol-formaldehyde resin, 1,3-bis (citraconimidomethyl)benzene, and 1,3-bis (citraconimidomethyl)benzol. For example, the one-or-more crosslinking agents can be the brominated octyl phenol-formaldehyde resin (e.g. SP-1056, Akrochem) and 1,3-bis (citraconimidomethyl)benzene (e.g., Perkalink® 900 RheinChemie Additives), optionally, together with a curative such as a zeolite (e.g., Rhenogran® Zeolite-70, RheinChemie Additives) to accelerate curing of the elastomeric composition by way of the brominated octyl phenol-formaldehyde resin, as well as a catalyst such as ZnO to catalyze formation of the conjugated dienes from the allylic bromides or allylic chlorides for reaction with the dienophile or electrophile of 1,3-bis (citraconimidomethyl)benzene to form the Diels- Alder adducts of the elastomeric composition.

[0087] Whether the halogenated alkyl-substituted phenol-formaldehyde resin is the brominated octyl phenol-formaldehyde resin or an analog thereof, the halogenated alkyl- substituted phenol-formaldehyde resin can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, or 15.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the halogenated alkyl-substituted phenol-formaldehyde resin can be no more than 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. As such, the concentration of the halogenated alkyl-substituted phenol-formaldehyde resin in the elastomeric formulation can be at least 1.0 phr and no more than 15.0 phr, including at least 2.0 phr and no more than 14.0 phr, such as at least 3.0 phr and no more than 13.0 phr, for example, at least 4.0 phr and no more than 12.0 phr.

[0088] Whether the 1,3-bis (citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol is present in the elastomeric formulation, the 1,3-bis(citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, or 15.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the 1,3-bis (citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol can be no more than 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. As such, the concentration of 1,3-bis (citraconimidomethyl)benzene or 1,3-bis (citraconimidomethyl)benzol in the elastomeric formulation can be at least 1.0 phr and no more than 15.0 phr, including at least 2.0 phr and no more than 14.0 phr, such as at least 3.0 phr and no more than 13.0 phr, for example, at least 4.0 phr and no more than 12.0 phr.

[0089] The one-or-more fillers can be inorganic fillers selected from the one-or more reinforcing fillers and at least the conductive filler set forth above, wherein the reinforcing fillers can be silicate fillers selected from silica, sodium silicate, potassium silicate, calcium silicate, magnesium silicate (e.g., Mistron® Vapor R, Magris Talc), and aluminum silicate, and wherein the conductive filler can be carbon black selected from acetylene black, channel black, furnace black, lamp black, and thermal black. For example, the one-or-more fillers can be magnesium silicate for the reinforcing filler of and acetylene black for the conductive filler.

[0090] Whether the reinforcing filler is silica, sodium silicate, potassium silicate, calcium silicate, magnesium silicate, aluminum silicate, or some combination thereof, the reinforcing filler can be at least 30, 35, 40, 45, 50, 55, 60, 65, or 70 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. Alternatively, the reinforcing filler can be no more than 70, 65, 60, 55, 50, 45, 40, 35, 30 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. As such, the concentration of the reinforcing filler in the elastomeric formulation can be at least 30 phr and no more than 70 phr, including at least 35 phr and no more than 65 phr, such as at least 40 phr and no more than 60 phr, for example, at least 45 phr and no more than 55 phr. Such a concentration of the reinforcing filler allows for an appropriate modulus and resistance to indentation of the elastomeric composition.

[0091] Whether the conductive filler is acetylene black, channel black, furnace black, lamp black, thermal black, or some combination thereof, the conductive filler can be in a concentration sufficient to achieve its percolation point in the elastomeric composition. Theconductive filler can be at least 1, 5, 10, 15, 20, 25, or 30 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. Alternatively, the conductive filler can be no more than 30, 25, 20, 15, 10, 5, or 1 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called ones or units place. As such, the concentration of the conductive filler in the elastomeric formulation can be at least 1 phr and no more than 30 phr, including at least 5 phr and no more than 25 phr, such as at least 10 phr and no more than 20 phr, for example, at least 15 phr and no more than 20 phr. Notably, advantageous elastomeric composition-property relationships were observed for the elastomeric composition and its resistance to beta radiation when the concentration of the conductive filler and the concentration of the chlorinated poly(isobutylene- co-isoprene) or chlorobutyl copolymer in the elastomeric formulation was 1.0 to 1.0.

[0092] The one-or-more additives can vary, as needed, to provide one or more functions in the elastomeric formulation or the elastomeric composition derived therefrom. For example, the one-or-more additives can be selected from curatives including the zeolite for accelerating the curing of the elastomeric composition by way of the brominated octyl phenolformaldehyde resin, catalysts including the ZnO for catalyzing formation of conjugated dienes from the allylic bromides or allylic chlorides, antioxidants or radical scavengers such as BHT, BHA, BHQ, or some combination thereof for scavenging radicals in the elastomeric composition resulting from the beta radiation, acid scavengers such as MgO for scavenging acid such as HBr or HC1 in the elastomeric composition resulting from formation of at least the conjugated dienes from the allylic bromides or allylic chlorides, and processing aids such as white mineral oil, one or more fatty acids such as stearic acid, oleic acid, behenic acid, lauric acid, and palmitic acid, or some combination thereof, the white mineral oil and the one-or-more fatty acids functioning as at least mold release agents.

[0093] Whether the curatives include the zeolite or one or more other curatives for accelerating the curing of the elastomeric composition, the curatives can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, or 15.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the curatives can be no more than 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. As such, the concentration of the curatives in the elastomeric formulation can be at least 1.0 phr and no more than 15.0 phr, including atleast 2.0 phr and no more than 14.0 phr, such as at least 3.0 phr and no more than 13.0 phr, for example, at least 4.0 phr and no more than 12.0 phr.

[0094] Whether the catalysts include the ZnO or one or more other catalysts for catalyzing one or more chemical reactions in the elastomeric formulation or the elastomeric composition derived therefrom, the catalysts can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the catalysts can be no more than 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. As such, the concentration of the catalysts can be at least 1.0 phr and no more than 10.0 phr, including at least 2.0 phr and no more than 9.0 phr, such as at least 3.0 phr and no more than 8.0 phr, for example, at least 4.0 phr and no more than 7.0 phr.

[0095] Notably, each of the two-or-polymers with their sites of unsaturation, the catalysts such as the ZnO for catalyzing formation of the conjugated dienes from the allylic bromides or allylic chlorides to provide additional sites of unsaturation, the crosslinking agents for forming the carbon-carbon crosslinks from the sites of unsaturation, and the curatives such as the zeolite for the curing of the elastomeric composition are selected to enable efficient crosslinking without an overabundance of the sites of unsaturation remaining in the elastomeric composition. Otherwise, such an overabundance of the sites of unsaturation remaining in the elastomeric composition can lead to degradation of the elastomeric composition by way the sites of unsaturation reacting with incident beta particles.

[0096] Whether the antioxidants or radical scavengers include the BHT, the BHA, the BHQ, or some combination thereof for scavenging radicals in the elastomeric composition, the antioxidants or radical scavengers can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the antioxidants or radical scavengers can be no more than 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. As such, the concentration of the antioxidants or radical scavengers in the elastomeric formulation can be at least 1.0 phr and no more than 10.0 phr, including at least 2.0 phr and no more than 9.0 phr, such as at least 3.0 phr and no more than 8.0 phr, for example, at least 4.0 phr and no more than 7.0 phr.

[0097] Whether the acid scavengers include the MgO or one or more other acid scavengers for scavenging acid in the elastomeric formulation or the elastomeric composition derived therefrom, the acid scavengers can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the acid scavengers can be no more than 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. As such, the concentration of the acid scavengers in the elastomeric formulation can be at least 1.0 phr and no more than 10.0 phr, including at least 2.0 phr and no more than 9.0 phr, such as at least 3.0 phr and no more than 8.0 phr, for example, at least 4.0 phr and no more than 7.0 phr.

[0098] As to processing aids such as the white mineral oil, the white mineral oil can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the white mineral oil can be no more than 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so- called tenths place. As such, the concentration of the white mineral oil in the elastomeric formulation can be at least 1.0 phr and no more than 10.0 phr, including at least 2.0 phr and no more than 9.0 phr, such as at least 3.0 phr and no more than 8.0 phr, for example, at least 4.0 phr and no more than 7.0 phr.

[0099] As to processing aids such as the one-or-more fatty acids, whether the one-or- more fatty acids include stearic acid, oleic acid, behenic acid, lauric acid, palmitic acid, or some combination thereof, the one-or-more fatty acids can be at least 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. Alternatively, the one-or-more fatty acids can be no more than 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0 phr in the elastomeric formulation, inclusive of any intervening concentrations defined by the so-called tenths place. As such, the concentration of the one-or-more fatty acids, in the elastomeric formulation can be at least 1.0 phr and no more than 10.0 phr, including at least 2.0 phr and no more than 9.0 phr, such as at least 3.0 phr and no more than 8.0 phr, for example, at least 4.0 phr and no more than 7.0 phr.

[0100] Some examples of the elastomeric formulation including the two-or-more copolymers, the one-or-more crosslinking agents, the one-or-more fillers, and the one-or-more additives are provided in Table 2 set forth below. Notably, the examples of the elastomericcomposition set forth in Table 1 above, namely Elastomeric Compositions 1-9, correspond to the examples of the elastomeric formulation set forth in Table 2 below, namely Elastomeric Formulations 1-9, respectively.Table 2. Examples of the elastomeric formulation.

[0101] Continuing with the method of making the elastomeric article, the loading Error! Bookmark not defined.operation can notably include, as above, the initial loading operation and the one-or-more additional loading operations, and the mixing operation can likewise include, as above, the initial mixing operation and the one-or-more additional mixing operations. While the method of making the elastomeric article is further set forth below with respect to the initial loading operation, the initial mixing operation, an additional loading operation, and an additional mixing operation, in the foregoing order, it should be understood the loading and mixing operations are not limited thereto. Indeed, the loading and mixing operations can include any number of loading and mixing operations in any order thereof, as needed, in accordance with an order in which different compounding ingredients should be added to the internal mixer of the Banbury machine in relation to each other, as well as conditions under which the compounding ingredients should to be mixed in the internal mixer to achieve certain properties of the elastomeric composition.

[0102] As to the initial loading operation, the initial loading operation can include loading up to all of the compounding ingredients but the one-or-more crosslinking agents into the internal mixer of the Banbury machine through the one-or-more input ports thereof.

[0103] As to the initial mixing operation, the initial mixing operation can include mixing up to all of the compounding ingredients but for the one-or-more crosslinking agents in the internal mixer of the Banbury machine by way of one or more rotors in different directions, at different speeds, or some combination thereof, thereby creating a shearing action for the mixing of the foregoing compounding ingredients. While such mixing can generate heat that softens the two-or-more copolymers and, thereby, facilitates dispersion of the one-or-more fillers and the one-or-more additives therethrough, heat, pressure, vacuum, or some combination thereof can be applied to the compounding ingredients in the internal mixer to further facilitate dispersion of the one-or-more fillers and the one-or-more additives through the two-or-more copolymers or as otherwise needed until adequately mixed.

[0104] As to the additional loading operation, the additional loading operation can include loading all remaining compounding ingredients including the one-or-more crosslinking agents into the internal mixer of the Banbury machine through the one-or-more input ports thereof, thereby completing the elastomeric formulation.

[0105] As to the additional mixing operation, the additional mixing operation can include mixing all of the compounding ingredients including the one-or-more crosslinking agents in the internal mixer of the Banbury machine by way of the one-or-more rotors in the different directions, at the different speeds, or some combination thereof. While such mixing can generate heat that softens the two-or-more copolymers and, thereby, facilitates dispersion of the one-or-more crosslinking agents therethrough, heat, pressure, vacuum, or some combination thereof can be applied to the compounding ingredients in the internal mixer to further facilitate dispersion of the one-or-more crosslinking agents through the two-or-more copolymers or as otherwise needed to ensure thorough distribution of the one-or-more crosslinking agents for uniform crosslinking of the two-or-more polymers and, thus, isotropic properties, in the elastomeric composition upon curing.

[0106] As to the different directions of the one-or-more rotors in the internal mixer of the Banbury machine, the different directions of the one-or-more rotors can be clockwise or counterclockwise, each rotor of the one-or-more rotors independent of every other rotor thereof.

[0107] As to the different speeds of the one-or-more rotors in the internal mixer of the Banbury machine, the different speeds of the one-or-more rotors can be at least 10, 20, 30, 40, 50, 60, 70, or 80 revolutions-per-minute (“RPMs”), each rotor of the one-or-more rotors independent of every other rotor thereof. Alternatively, the different speeds of the one-or-more rotors can be no more than 80, 70, 60, 50, 40, 30, 20, or 10 RPMs, each rotor of the one-or- more rotors independent of every other rotor thereof. As such, the different speeds of the one- or-more rotors can be at least 10 RPMs and no more than 80 RPMs, including at least 20 RPMs and no more than 70 RPMs, such as at least 30 RPMs and no more than 60 RPMs, for example, at least 40 RPMs and no more than 50 RPMs, each rotor of the one-or-more rotors independent of every other rotor thereof.

[0108] As to the heat applied to the compounding ingredients in the internal mixer of the Banbury machine to facilitate dispersion of the one-or-more fillers, the one-or-more additives, the one-or-more crosslinking agents, or some combination thereof through the two- or-more copolymers, the heat applied can result in an internal temperature of at least 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, 190 °C, or 200 °C. Alternatively, the heat applied to the compounding ingredients in the internal mixer can result in an internal temperature of no more than 200 °C, 190 °C, 180 °C, 170 °C, 160 °C, 150 °C,140 °C, 130 °C, 120 °C, 110 °C, or 100 °C. As such, the heat applied to the compounding ingredients in the internal mixer can result in an internal temperature of at least 100 °C and no more than 200 °C, including at least 110 °C and no more than 190 °C, such as at least 120 °C and no more than 180 °C, for example, at least 130 °C and no more than 170 °C.

[0109] The discharging operation can include discharging a nascent elastomeric composition from one or more output ports of the internal mixer of the Banbury machine in a continuous sheet-like form upon adequately mixing the compounding ingredients.

[0110] The molding operation can include placing the sheet-like form of the nascent elastomeric composition in a mold such as a compression mold and molding the nascent elastomeric composition into the elastomeric article.[OHl] The curing operation can include applying heat, pressure, or both heat and pressure to the mold during the molding operation or the elastomeric article upon its release from the mold. The curing operation completes crosslinking in the elastomeric composition, thereby imparting properties to the elastomeric composition and the elastomeric article thereof such as those set forth above in Table 1.

[0112] As to the heat applied to the mold during the molding operation or the elastomeric article upon its release from the mold, the heat applied can result in an internal temperature of at least 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, 190 °C, or 200 °C. Alternatively, the heat applied to the mold or the elastomeric article can result in an internal temperature of no more than 200 °C, 190 °C, 180 °C, 170 °C, 160 °C, 150 °C, 140 °C, 130 °C, 120 °C, 110 °C, or 100 °C. As such, the heat applied to the mold or the elastomeric article can result in an internal temperature of at least 100 °C and no more than 200 °C, including at least 110 °C and no more than 190 °C, such as at least 120 °C and no more than 180 °C, for example, at least 130 °C and no more than 170 °C.

[0113] As to the pressure applied to the mold during the molding operation or the elastomeric article upon its release from the mold, the pressure applied can be at least 1, 5, 10, 15, 20, 25, 30, 35, or 40 MPa. Alternatively, the pressure applied to the mold or the elastomeric article can be no more than 40, 35, 30, 25, 20, 15, 10, 5, or 1 MPa. As such, the pressure applied to the mold or the elastomeric article can be at least 1 MPa and no more than 40 MPa, including at least 5 MPa and no more than 35 MPa, such as at least 10 MPa and no more than 30 MPa, for example, at least 15 MPa and no more than 25 MPa.

[0114] Such a curing operation of applying heat, pressure, or both heat and pressure to the mold during the molding operation or the elastomeric article upon its release from the mold provides optimized cure kinetics for improved manufacturability. For example, the heat applied resulting in the internal temperature of 180 °C provides a T90 or time it takes to reach 90% of a maximum cure of less than 13 minutes.

[0115] While some particular embodiments have been disclosed herein, and while the particular embodiments have been disclosed in some detail, it is not the intention for the particular embodiments to limit the scope of the concepts provided herein. Additional adaptations or modifications can appear to those of ordinary skill in the art, and, in broader aspects, these adaptations or modifications are encompassed as well. Accordingly, departures may be made from the particular embodiments disclosed herein without departing from the scope of the concepts provided herein.

Claims

CLAIMSWhat is claimed is:

1. A beta radiation-resistant elastomeric composition, comprising: a polymer blend including a first copolymer and a second copolymer; carbon-carbon crosslinks between polymer chains of the first copolymer, polymer chains of the second copolymer, the polymer chains of the first and second copolymers, or some combination thereof; and one or more fillers including at least a conductive filler in a concentration sufficient to achieve its percolation point in the elastomeric composition, the conductive filler forming a three-dimensional conductive network throughout the elastomeric composition configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks and, thereby, conferring resistance of the elastomeric composition to the beta radiation.

2. The elastomeric composition of claim 1, wherein the first copolymer is a brominated poly(isobutylene-co-isoprene) including one or more chemical moieties selected from allylic bromides, primary conjugated dienes derived from the allylic bromides, and primary Diels-Alder adducts derived from the primary conjugated dienes and one or more dienophiles, the primary Diels-Alder adducts involved in at least a portion of the carbon-carbon crosslinks when the primary Diels-Alder adducts are formed between the polymer chains of the first copolymer, the polymer chains of the first and second copolymers, or some combination thereof.

3. The elastomeric composition of claim 2, wherein the one-or-more dienophiles are selected from l,3-bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

4. The elastomeric composition of any claim of claims 1-3, wherein the second copolymer is a terpolymer derived from an ethylene monomer, a propylene monomer, and a diene monomer.

5. The elastomeric composition of claim 4, wherein the second copolymer includes residues of ethylidene norbornene (“ENB”), vinyl norbornene (“VNB”), or dicyclopentadiene (“DCPD”) corresponding to the diene monomer.

6. The elastomeric composition of any claim of claims 1-5, wherein the polymer blend further comprises a third copolymer, the carbon-carbon crosslinks further between polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

7. The elastomeric composition of claim 6, wherein the third copolymer is a chlorinated poly(isobutylene-co-isoprene) including one or more chemical moieties selected from allylic chlorides, secondary conjugated dienes derived from the allylic chlorides, and secondary Diels-Alder adducts derived from the secondary conjugated dienes and one or more electrophiles, the secondary Diels-Alder adducts involved in at least a portion of the carboncarbon crosslinks when the secondary Diels-Alder adducts are formed between the polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

8. The elastomeric composition of claim 7, wherein the one-or-more electrophiles are selected from l,3-bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

9. The elastomeric composition of any claim of claims 1-8, wherein at least a portion of the carbon-carbon crosslinks include an alkyl-substituted phenol-formaldehyde resin crosslinking one or more copolymers of the polymer blend by way of tetrahydropyran adducts.

10. The elastomeric composition of claim 9, wherein the one-or-more fillers further include a magnesium silicate and a zeolite as a reinforcing filler, at least a portion of the zeolite being spent zeolite remaining in the elastomeric composition after curing the elastomeric composition to establish the carbon-carbon crosslinks from the alkyl-substituted phenolformaldehyde resin.

11. The elastomeric composition of any claim of claims 1-10, wherein the one-or- more fillers further include an antioxidant as a stabilizing filler.

12. The elastomeric composition of any claim of claims 1-11, wherein the conductive filler includes a carbon allotrope having a graphitic content of at least 40% by weight of the carbon allotrope.

13. The elastomeric composition of any claim of claims 1-12, wherein the elastomeric composition has a Shore-A durometer of 40-55; a tensile strength of 3.4-6.2 MPa both before and after a dose of beta radiation up to 80 kGy, the tensile strength before the dose of beta radiation being greater than that after the dose of beta radiation; and an elongation at break of 425 -725 both before and after the dose of beta radiation up to 80 kGy, the elongation at break before the dose of beta radiation being greater than that after the dose of beta radiation.

14. A beta radiation-resistant elastomeric article of manufacture, comprising: an elastomeric composition resistant to beta radiation, the elastomeric composition including: a polymer blend including a first copolymer and a second copolymer; carbon-carbon crosslinks between polymer chains of the first copolymer, polymer chains of the second copolymer, the polymer chains of the first and second copolymers, or some combination thereof; and one or more fillers including at least a conductive filler in a concentration sufficient to achieve its percolation point in the elastomeric composition, the conductive filler forming a three-dimensional conductive network throughout the elastomeric composition configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks and, thereby, conferring resistance of the elastomeric article to the beta radiation.

15. The elastomeric article of claim 14, wherein the first copolymer is a brominated poly(isobutylene-co-isoprene) including one or more chemical moieties selected from allylic bromides, primary conjugated dienes derived from the allylic bromides, and primary Diels- Alder adducts derived from the primary conjugated dienes and one or more dienophiles, the primary Diels-Alder adducts involved in at least a portion of the carbon-carbon crosslinks when the primary Diels- Alder adducts are formed between the polymer chains of the first copolymer, the polymer chains of the first and second copolymers, or some combination thereof.

16. The elastomeric article of claim 15, wherein the one-or-more dienophiles are selected from l,3-bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

17. The elastomeric article of any claim of claims 14-16, wherein the second copolymer is a terpolymer derived from an ethylene monomer, a propylene monomer, and a diene monomer.

18. The elastomeric article of claim 17, wherein the second copolymer includes residues of ethylidene norbornene (“ENB”), vinyl norbornene (“VNB”), or dicyclopentadiene (“DCPD”) corresponding to the diene monomer.

19. The elastomeric article of any claim of claims 14-18, wherein the polymer blend further comprises a third copolymer, the carbon-carbon crosslinks further between polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

20. The elastomeric article of claim 19, wherein the third copolymer is a chlorinated poly(isobutylene-co-isoprene) including one or more chemical moieties selected from allylic chlorides, secondary conjugated dienes derived from the allylic chlorides, and secondary Diels- Alder adducts derived from the secondary conjugated dienes and one or more electrophiles, the secondary Diels-Alder adducts involved in at least a portion of the carbon-carbon crosslinks when the secondary Diels-Alder adducts are formed between the polymer chains of the third copolymer, the polymer chains of the first and third copolymers, the polymer chains of the second and third copolymers, the polymer chains of the first, second, and third copolymers, or some combination thereof.

21. The elastomeric article of claim 20, wherein the one-or-more electrophiles are selected from l,3-bis(citraconimidomethyl)benzene and 1,3-bis (citraconimidomethyl)benzol.

22. The elastomeric article of any claim of claims 14-21, wherein at least a portion of the carbon-carbon crosslinks include an alkyl-substituted phenol-formaldehyde resin crosslinking one or more copolymers of the polymer blend by way of tetrahydropyran adducts.

23. The elastomeric article of claim 22, wherein the one-or-more fillers further include a magnesium silicate and a zeolite as a reinforcing filler, at least a portion of the zeolitebeing spent zeolite remaining in the elastomeric composition after curing the elastomeric composition to establish the carbon-carbon crosslinks from the alkyl-substituted phenolformaldehyde resin.

24. The elastomeric article of any claim of claims 14-23, wherein the one-or-more fillers further include an antioxidant as a stabilizing filler.

25. The elastomeric article of any claim of claims 14-24, wherein the conductive filler includes a carbon allotrope having a graphitic content of at least 40% by weight of the carbon allotrope.

26. The elastomeric article of any claim of claims 14-25, wherein the elastomeric article is a septum molded from the elastomeric composition.

27. The elastomeric article of claim 26, wherein the septum has a Shore-A durometer of 40-55; a tensile strength of 3.4-6.2 MPa both before and after a dose of beta radiation up to 80 kGy, the tensile strength before the dose of beta radiation being greater than that after the dose of beta radiation; and an elongation at break of 425 -725 both before and after the dose of beta radiation up to 80 kGy, the elongation at break before the dose of beta radiation being greater than that after the dose of beta radiation.

28. A method of making a beta radiation-resistant elastomeric article of manufacture, comprising: one or more loading operations of loading compounding ingredients of an elastomeric formulation into an internal mixer, the compounding ingredients including: a first copolymer; a second copolymer; one or more crosslinking agents; and one or more fillers including a conductive filler; one or more mixing operations of mixing the compounding ingredients in the internal mixer; a discharging operation of discharging a nascent elastomeric composition from the internal mixer in a continuous sheet-like form; a molding operation of molding the nascent elastomeric composition into the elastomeric article in a compression mold; anda curing operation of applying heat, pressure, or both to the compression mold to establish or complete crosslinking in a final elastomeric composition of the elastomeric article, the final elastomeric composition including: a polymer blend including the first copolymer and the second copolymer; carbon-carbon crosslinks between polymer chains of the polymer blend; and one or more fillers including at least the conductive filler in a concentration sufficient to achieve its percolation point in the final elastomeric composition, the conductive filler forming a three-dimensional conductive network throughout the final elastomeric composition configured to conduct beta radiation away from the carbon-carbon crosslinks for maintaining an integrity of the carbon-carbon crosslinks and, thereby, conferring resistance of the elastomeric article to the beta radiation.

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