Lead-free ammunition projectile

Abstract

A bullet (ammunition projectile) is described that includes a branched condensation polymer and a filler, where the filler is present in an amount of about 10% to 65% by volume of the branched condensation polymer and filler. The cartridge may be manufactured by heating a mixture of a branched condensation polymer and a filler comprised of first and second fillers having different densities and different particle size distributions to form a molten mixture, and injecting the molten mixture into a mold to form the ammunition projectile, thus, the characteristics of the bullet are allowed to be customized for different applications.

Description

Technical Field

[0001] The present disclosure is directed to a lead-free ammunition projectile comprising a branched condensation polymer and a filler. The present disclosure is also directed to a method of making an ammunition projectile. Background Art

[0002] Lead is the most widely used ammunition metal due to its relatively low cost, low melting temperature, and high density. However, the environmental and health risks associated with lead have led to a comprehensive movement to eliminate its use in many applications, including lead-containing ammunition. For example, lead contamination at shooting ranges has been a problem for many years due to poor air circulation after indoor shooting and the accumulation of projectiles at outdoor shooting ranges. Addressing this issue has become even more important in recent years due to the current focus on reducing lead contamination.

[0003] In addition, in many types of training situations and confrontation situations, the use of lethal ammunition is not appropriate. During shooting practice, there is a potential risk of injury due to ricochet. When a bullet hits a surface at a certain angle, the kinetic energy it carries may not be fully dissipated through the bullet's rupture or deformation, that is, part of the energy may remain in the deformed bullet or bullet fragments, which may cause unnecessary injury or collateral damage to other people or objects.

[0004] This effect can be avoided or minimized by making the bullet more "fragile," that is, by making it easier for the bullet to break into small pieces when it hits its primary target, so that the energy associated with these tiny fragments of the bullet is very small and the collateral damage they can cause is minimal.

[0005] However, previous attempts at non-lead ammunition (e.g., filled plastic bullets) have suffered from one or more drawbacks that have prevented their widespread use. For example, existing non-metallic ammunition tends to break apart (i.e., the individual components separate from one another) during firing. Because it is difficult to adequately load the filler in plastic, the bullets tend to be light in mass, which can result in reduced accuracy (i.e., bullet tumble can occur). When the bullet is highly loaded, the filler distribution can be uneven, which can also result in reduced accuracy.

[0006] It would be desirable to provide a lead-free "green" ammunition projectile that is relatively easy and economical to manufacture and use, and that provides a structure that can be adjusted based on the desired bullet properties and can withstand the forces within the ammunition during firing. For example, it would be desirable to provide a lead-free polymer based ammunition that, when fired in situations where a frangible bullet is preferred, will frangible upon impact, but otherwise function like a conventional bullet. Summary of the invention

[0007] It has been discovered that bullets (ammunition projectiles) with desired properties can be achieved through the use of branched polymers with specific properties that allow high and flexible loading of high density fillers while achieving desired bullet characteristics, such as the ability to behave in different ways depending on the target material, improved barrel lubricity and reduced toxicity, while achieving a uniform high density bullet.

[0008] One aspect of the present disclosure is directed to an ammunition projectile comprising: a branched condensation polymer and a filler, wherein the filler is present in an amount of about 10% to 65% by volume of the branched condensation polymer and the filler.

[0009] Another aspect of the present disclosure is directed to a method of forming an ammunition projectile, the method comprising heating a mixture of a branched condensation polymer and a filler to form a molten mixture, the filler being comprised of first and second fillers having different densities and different particle size distributions, and injecting the molten mixture into a mold to form an ammunition projectile. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] When combined with Figure 1 The present disclosure can be best understood when reading the following detailed description. It should be emphasized that, according to common practice, the various features of the drawings are not drawn to scale. Instead, the sizes of the various features are arbitrarily expanded or reduced for clarity.

[0011] Figure 1 Depicted is the particle size distribution of the stainless steel filler incorporated into the ammunition projectiles of the present disclosure.

[0012] Figure 2 Depicted is the particle size distribution of the stainless steel filler incorporated into the ammunition projectiles of the present disclosure.

[0013] Figure 3 Particle size distribution of tungsten incorporated into ammunition projectiles of the present disclosure is depicted.

[0014] Figure 4 is an optical micrograph of a polished cross-section of an ammunition projectile of the present disclosure.

[0015] Figure 5 is an optical micrograph of a polished cross-section of a commercial ammunition projectile not of the present disclosure. DETAILED DESCRIPTION

[0016] While the present disclosure has been described in conjunction with certain embodiments, it should be understood that the present disclosure is not limited to the disclosed embodiments, but on the contrary, the present disclosure is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope should be given the broadest interpretation so as to encompass all such modifications and equivalent structures permitted by law.

[0017] Unless otherwise expressly stated, all numerical values ​​in this specification should be understood as modified by the word "about", and all geometric and spatial descriptors should be understood as modified by the word "substantially", to describe the broadest scope of the technology. When "about" is used for a numerical value, it means that the calculation or measurement allows for slight imprecision in the value (the value is close to precision to some extent; approximately or reasonably close to the value; almost). If for some reason the imprecision provided by "about" and / or "substantially" cannot be understood in this ordinary sense in the art, then the "about" and / or "substantially" used herein at least indicates the variation that may result from ordinary methods of measuring or using such parameters.

[0018] An ammunition projectile comprising a branched polymer and a filler is disclosed. The branched polymer can be any polymer generally understood to be branched, including polymers referred to as hyperbranched, dendritic, etc., as long as it has specific melt flow characteristics to adequately load the filler and maintain the desired properties.

[0019] The branched polymer is preferably a branched condensation polymer. The branched polymer may be any condensation polymer that can be shaped and can produce an ammunition projectile having the desired properties. Commercially available condensation polymers often have a weight average molecular weight (MW) greater than 500,000 or 1,000,000 Da. w ) and low molecular weight and low melt flow rate (i.e., less than 10,9 g / 10 / min measured at 2.16 kg at 235°C). In order to achieve the desired melt flow while also having the necessary thermorheological behavior to allow uniform dispersion of the filler even with a high mass (e.g., at least 10 g / cc), it has been found that branched condensation polymers that are chain-broken by chain-breaking / capping compounds incorporated into the condensation polymer may be particularly suitable, such as described in co-pending application PCT / US2021 / 019391 (WO2021 / 173651), which is incorporated herein by reference.

[0020] Illustratively, the polymer is a condensation polymer such as polyamide, polycarbonate and polyester having 1% to 3% by weight of a chain-breaking / capping compound "SE compound". It is understood that SE compounds are chemically bonded at room temperature but may break at elevated temperatures, which may result in a different structure being formed upon continued heating. Examples of SE compounds that are particularly suitable for polyamides and polyesters include anhydrides and carboxylic acids such as phthalic anhydride, tetrabromophthalic anhydride, hexahydrophthalic anhydride, sulfophthalic anhydride, trimellitic anhydride, 1,8-naphthalic anhydride.

[0021] SE compounds can introduce useful chemical groups that impart desired properties or characteristics, such as flame retardancy, UV resistance, or other functionalities, such as the ability to further react with different polymers or reactive groups. For example, end-capping compounds (e.g., anhydrides) can have variable functionalities as follows. An end-capping compound (e.g., anhydride) may react only once with a polyamide (functionality of 1), but with a polyester with a functionality of 2, so an end-capping compound that caps a polyamide may have residual functionality that allows it to react with a polyester (if desired). It is not clear at present, but such polymers may rearrange to form different structures (e.g., from branched to hyperbranched to dendritic) each time they are continuously heated to a temperature above the temperature at which the condensation polymer flows and begins to crack. Typically, such heating reaches temperatures of at least 200°C, 250°C, 275°C, 300°C, or higher.

[0022] Examples of suitable branched condensation polymers may include polyamides, polyesters, polyacetals, polycarbonates, or combinations thereof. Any suitable branched condensation polymer may be used, including hyperbranched condensation polymers. Exemplary branched condensation polymers include nylon 6 / 66 / 12, which is subjected to the method described in WO2021 / 173651, which is incorporated herein by reference.

[0023] The branched condensation polymer has a melt flow rate sufficient to produce the desired ammunition projectiles having the desired properties discussed in this application. The melt flow is at least 10, 15 or 20 to 50, 75 or 100 as measured using ASTM D1238 (2.16 kg at 235° C., [g / 10 min.]).

[0024] The amount of filler is sufficient to provide the projectile with the desired mass and other properties suitable for the particular application. Generally, the amount of filler is at least 10% up to any feasible amount where the polymer is unable to adequately bind the filler particles during firing, which may depend on the particular application and the polymer used, with typical amounts being up to 65%, 60% or 55%.

[0025] The ammunition projectile includes a filler. The filler can be any material that can be mixed with the branched polymer and can produce an ammunition projectile with desired properties. The filler can include an inorganic compound having a density of about 5 g / cc or greater, about 8 g / cc or greater, about 10 g / cc or greater. The inorganic compound can include a transition metal. The filler can include at least one compound consisting of copper, tungsten, iron, bismuth, tantalum, zinc, antimony, and mixtures thereof. The compound can be an alloy or ceramic, such as an oxide, carbide, nitride, or a combination thereof (e.g., tungsten oxide, tungsten carbide, and ceramic metal composites, such as WC-Co).

[0026] The filler may have a particle size and particle size distribution that is conducive to the manufacture of ammunition projectiles having the desired characteristics discussed in this application. In defining useful sizes, the particle size and size distribution are given by the median size (D50), D10, D90, and the maximum size limit (D100). The sizes are equivalent spherical diameters by volume, as measured by laser scattering methods (Rayleigh or Mie, with Mie scattering being preferred) using dispersion of solids in liquids with low solid loadings. By volume, D10 is the size at which 10% of the particles have a smaller size, D50 (median) is the size at which 50% of the particles have a smaller size, and D90 is the size at which 90% of the particles have a smaller size. Typically, the filler has an equivalent spherical diameter median (D50) particle size of about 10 μm to about 130 μm, about 20 μm to about 120 μm, about 25 μm to about 115 μm; a D10 of about 1 μm to about 70 μm, 5 μm to about 60 μm, 10 μm to about 50 μm; a D90 of about 70 μm to about 215 μm, 60 μm to about 210 μm, 40 μm to about 200 μm; a D100 of about 50 μm to about 250 μm, about 45 μm to about 150 μm, about 40 μm to about μm. The filler may have a particle size of about 125 μm or less, or about 100 μm or less, or 50 μm or less, or 30 μm or less, or 25 μm. The filler may have an average particle size of about 5 μm to about 110 μm, about 25 μm to about 110 μm.

[0027] The filler may comprise a mixture of one or more inorganic compounds. The filler may comprise a mixture of two or more inorganic compounds. The two or more inorganic compounds may have different particle size distributions. The two or more inorganic compounds may include a low-density compound and a high-density compound. As used herein, a low-density compound is any compound having a density less than about 10 g / cc. As used herein, a high-density compound is any compound having a density greater than about 10 g / cc. For example, a low-density compound may be a compound made of iron, and a high-density compound may be a compound made of tungsten.

[0028] Surprisingly, branched condensation polymers allow for uniform incorporation of high density fillers throughout the bullet, such as when injection molded. This allows, for example, the performance of the bullet to be tailored for different situations that may be encountered. It also allows for densities equal to or higher than copper bullets, even though this may not be necessary for the desired properties in most situations. For example, the density of the bullet can be in any useful range, but is typically from about 2 g / cc, 3 g / cc, or 4 g / cc to 9 g / cc, 8 g / cc, 7 g / cc, or 6 g / cc. Uniform distribution can be determined by randomly selecting 10 approximately 8 mm 3The method may be performed by measuring the volume of a random cube of the bullet to determine the amount of filler in that volume, or by physically slicing the bullet and measuring the density of the cubes, where uniform means that the density of all cubes is within 5% of the average of the cubes, but preferably within 3%, 2% or even 1%. Similarly, the method may be performed using a randomly selected 4 mm cube from the bullet. 2 The random surface density in a square area.

[0029] The filler may include a compound consisting of iron with an average particle size of about 25 μm to about 110 μm and a compound consisting of tungsten with an average particle size of about 5 μm to about 10 μm. The content of the compound consisting of iron can be present in an amount of about 10 volume % to about 50 volume % of the branched condensation polymer and the filler. The content of the compound consisting of tungsten can be present in an amount of about 0.1 volume % or 1 volume % to about 20 volume % or 15 volume % of the branched condensation polymer and the filler. Unexpectedly, finer fillers achieve higher solid loadings because larger surface areas must be wetted by finer powders of the polymer.

[0030] The ammunition projectile may also be composed of additives commonly used in polymers, such as lubricants, thermoplastic adhesives, pigments or combinations thereof. Any suitable lubricant capable of manufacturing an ammunition projectile with the desired properties discussed in this application may be used. The lubricant may include one or more of a fatty acid metal salt and a solid lubricant. Exemplary solid lubricants (e.g., lubricants with a plate-like structure) include one or more of talc, boron nitride, molybdenum disulfide and clay. The lubricant may include an aliphatic polyketone, such as an aliphatic polyketone described in a co-pending U.S. application (U.S. Patent Publication No. 2022 / 0363825A1), which is incorporated herein by reference.

[0031] The lubricant may be present in the ammunition projectile in an amount sufficient to facilitate manufacturing the desired ammunition projectile having the desired properties as discussed in this application.

[0032] Any suitable thermoplastic binder capable of producing an ammunition projectile having the desired properties discussed in this application may be used. The thermoplastic binder may include one or more of hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, cellulose gum, and hydroxyalkyl starch. The thermoplastic binder may be present in the ammunition projectile in an amount sufficient to facilitate production of the desired ammunition projectile having the desired properties.

[0033] Any suitable pigment capable of producing an ammunition projectile having the desired characteristics discussed in this application may be used. The pigment may include any pigment known and used in the industry. The pigment may be present in the ammunition projectile in a sufficient amount to allow the ammunition projectile to have the desired color and facilitate the production of the desired ammunition projectile having the desired characteristics discussed in this application.

[0034] The amount of additives can be any useful amount, and the amount of each additive and the amount of total additives present can be 0.1 wt%, 0.5 wt%, or to about 10 wt%, 5 wt%, or 2 wt%.

[0035] The ammunition projectile may be formed by any means sufficient to produce a projectile having the properties described herein. Exemplary processes include injection molding, thermoforming, and extrusion, with further machining if desired. Injection molding of the ammunition projectile may be accomplished by multi-point or single-point injection.

[0036] Illustratively, the bullet can be formed by a molding process such as injection molding as is generally understood in the art, which includes heating a mixture consisting of a branched condensation polymer and a filler and injecting the molten mass into a mold. In a specific example, the filler consists of a first and a second filler having different densities and different particle size distributions, as described herein.

[0037] In addition, it has been found that the combination of branched condensation polymers and fillers having particle sizes described herein achieves injection molded pellets in which the particles are encapsulated by the branched polymer even when the filler loading is at least 20%, 30%, 35%, or 40% to 60% or 50% by volume. As used herein, "encapsulated" means that there are substantially no exposed filler particles on the surface of the injection molded pellet. Essentially, this is when no more than or 1% of the surface has exposed filler particle surfaces, as determined by microphotography. In particular, it has been found that even when the density of the powders varies greatly, such as a difference of 2, 3, 4, 5, or 6 g / cc or more between the filler densities (e.g., W = 19.28 g / cc and Fe 7.87 g / cc), the particle size distribution of the lower density and higher density fillers described above can achieve uniform distribution and encapsulation of the filler.

[0038] When more than one filler is used, any useful density difference between the fillers can be utilized as described herein. In a specific example, the first filler can be any compound having a density less than about 10 g / cc (low density filler). The second filler can be any compound having a density greater than about 10 g / cc (high density filler). Density can be measured by weight and size using, for example, the Archimedean method. For example, the first filler can be a compound consisting of iron, and the second filler can be a compound consisting of tungsten. The first filler can have an average particle size of about 25 μm to about 110 μm, and the second filler can have an average particle size of about 5 μm to about 10 μm, or vice versa. The low-density filler can be any useful amount, but is generally present in an amount of 10% to about 50% of the volume of the mixture (bullet volume). The high-density filler can be present in any amount, but is generally at least about 0.1%, 1%, 5% or 10% to 30% or 20% of the volume of the bullet. Surprisingly, finer fillers achieve higher solid loadings because a larger surface area must be wetted by the polymer.

[0039] The mold may be any acceptable ammunition projectile size, such as the commonly used sizes: 5.56mm, 7.62mm, 50 caliber, 45 caliber, 380 caliber, 38 caliber, 9mm, 10mm, 12.7mm, 14.5mm, or 14.7mm cartridges.

[0040] Example

[0041] Formulations 1 and 2 with different solid contents were formed by combining branched polyamide 6 / 66 / 12 (UBE 6434, melt flow rate of about 1.9 (2.16 kg at 235° C. [g / 10 min])) modified using the method described in WO2021 / 173651 to have a melt flow rate of 20 to 80 with ATW-150 stainless steel having an average particle size of about 114 microns. The particle size distribution of the stainless steel is as follows Figure 1 The resulting formulations 1 and 2 are shown in Table 1.

[0042] Formulation 3 was formed in the same manner as above, except that the filler was ATW-150 stainless steel having an average particle size of about 25 microns. The particle size distribution of the stainless steel is as follows: Figure 2 The resulting Formulation 3 is shown in Table 1. The particle size distribution of ATW-150 was varied to achieve a loading of 46.5% by volume before injection molding issues were encountered.

[0043] Formulations 4-9 with different solid contents were formed by combining branched polyamide 6 / 66 / 12 (UBE 6434, melt flow rate of about 1.9 (2.16 kg at 235° C. [g / 10 min])) modified using the method described in WO2021 / 173651 to have a melt flow rate of 20 to 80 with ATW-150 stainless steel having an average particle size of about 114 microns and tungsten having an average particle size of about 7.6 microns. The particle size distribution of the stainless steel is as follows Figure 1 The particle size distribution of tungsten is shown in Figure 3 The resulting formulations 4-9 are shown in Table 1. This ATW-150 steel could be loaded into this particular branched polymer up to 42.6 vol%, with problems occurring at 45.5 vol%.

[0044] Table 1

[0045]

[0046]

[0047] Comparative Example 1 was obtained from Ecomass High Gravity Compound 1850ZN84T1, available from Ecomass Technologies, Austin TX.

[0048] The exemplary formulations and Comparative Example 1 were injection molded and subjected to standard IZOD impact testing as described in ASTM D256. Formulation 8 exhibited an unmeasured linear elasticity of 285.21 (14.07 kJ / m), Formulation 3 exhibited an unmeasured linear electrical resistance of 266.81 (10.76 kJ / m), and Comparative Example 1 exhibited an unmeasured linear electrical resistance of 136.18 (5.721 kJ / m). This is surprising given that Comparative Example 1 has a much lower filler loading and is a linear polyamide (PA6) as described below.

[0049] The cross section of the injection molded cylinder Formulation 9 was polished and observed under a microscope to check the density and distribution of the metal particles therein. Optical micrographs of Formulation 9 and Comparative Example 1 are shown in Figures 1 and 2, respectively. Figure 4 and Figure 5 The metal particles of Formulation 9 have an area density of 40% metal to 60% resin ( Figure 5 ), while Comparative Example 1 has an areal density of 24.3% metal.

[0050] Comparative Example 2 was prepared in the same manner as the Exemplary Formulation, except that the condensation polymer was a commercially available 6 / 66 / 12 polyamide. Injection molding of Comparative Example 2 was problematic even with a 30% volume loading of ATW-150 stainless steel.

Claims

1. An ammunition projectile, the ammunition projectile comprising: Branched condensation polymers, and A filler, wherein the filler is present in an amount of about 10% to 65% by volume of the branched condensation polymer and the filler.

2. The ammunition projectile of claim 1 wherein the branched condensation polymer has a melt flow rate of from 10 g / 10 min to 80 g / 10 min (2.16 kg at 235°C).

3. An ammunition projectile as claimed in claim 1 or claim 2 wherein the melt flow rate is at least 20 g / 10 min (2.16 kg at 235°C).

4. The ammunition projectile of any of the preceding claims, wherein the branched condensation polymer comprises one or more of a polyamide, a polyester, a polyacetal, and a polycarbonate.

5. The ammunition projectile of any of the preceding claims wherein the branched condensation polymer comprises said polyamides, polyesters, and combinations thereof.

6. An ammunition projectile as claimed in any one of the preceding claims wherein the branched condensation polymer is comprised of a chain breaking / extension compound.

7. The ammunition projectile of claim 6 wherein the chain breaking / extension compound is present in an amount of 1% to 3% by weight of the branched condensation polymer.

8. The ammunition projectile of claim 7 wherein the chain breaking / extending compound is comprised of a carboxylic acid or anhydride.

9. An ammunition projectile as claimed in any one of the preceding claims wherein the filler comprises an inorganic compound having a density of 7 g / cc to 20 g / cc.

10. The ammunition projectile of claim 9 wherein the ammunition projectile has a density of 4 g / cc to 9 g / cc.

11. An ammunition projectile as claimed in any one of the preceding claims wherein the inorganic compound comprises a transition metal.

12. The ammunition projectile of any of the preceding claims, wherein the filler is comprised of one or more of oxides, carbides, nitrides, and combinations thereof.

13. The ammunition projectile of any of the preceding claims, wherein the filler comprises one or more of: copper, tungsten, iron, bismuth, tantalum, zinc, antimony, and combinations and alloys thereof.

14. An ammunition projectile as claimed in any one of the preceding claims wherein the filler has an average particle size of from about 5 μm to about 110 μm.

15. The ammunition projectile of claim 13, wherein the filler has an average particle size of about 25 μm to about 110 μm.

16. An ammunition projectile as claimed in any one of the preceding claims wherein the filler has a particle size distribution of from about 10 μm to about 130 μm.

17. An ammunition projectile as claimed in any one of the preceding claims wherein the filler comprises one or more of tungsten and iron.

18. The ammunition projectile of any of the preceding claims, wherein the filler comprises at least one of tungsten metal, tungsten oxide, tungsten carbide, and a tungsten alloy.

19. An ammunition projectile as claimed in any one of the preceding claims wherein the filler is comprised of a compound comprised of iron having an average particle size of about 25 μm to 110 μm and a compound comprised of tungsten having an average particle size of about 5 μm to about 10 μm.

20. The ammunition projectile of claim 19 wherein the compound comprised of iron is present in an amount from about 10% to about 50% by volume of the branched condensation polymer and filler and the compound comprised of tungsten is present in an amount from greater than 0% to about 20% by volume of the branched condensation polymer and filler.

21. An ammunition projectile as claimed in any one of the preceding claims wherein the projectile further comprises an additive in an amount of 0.1% to 10% by weight of the ammunition projectile.

22. The ammunition projectile of claim 21 wherein the additive comprises a lubricant.

23. The ammunition projectile of claim 22, wherein the lubricant comprises one or more of a fatty acid metal salt and a solid lubricant.

24. The ammunition projectile of claim 22, wherein the lubricant comprises a solid lubricant comprised of one or more of talc, boron nitride, molybdenum disulfide, and clay.

25. The ammunition projectile of claim 22 wherein the lubricant comprises an aliphatic polyketone.

26. The ammunition projectile of claim 21 wherein the additive comprises a thermoplastic binder.

27. The ammunition projectile of claim 26, wherein the thermoplastic binder comprises hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, cellulose gum, and hydroxyalkyl starch.

28. The ammunition projectile of claim 21 wherein the additive comprises a pigment.

29. A method of forming an ammunition projectile, the method comprising: (i) heating a mixture consisting of a branched condensation polymer and a filler to form a molten mixture, the filler consisting of first and second fillers having different densities and different particle size distributions, and (ii) injecting the molten mixture into a mold to form the ammunition projectile.

30. The method of claim 29, wherein the first filler has a density less than about 10 g / cc and the second filler has a density greater than about 10 g / cc.

31. The method of claim 29 or claim 30, wherein the first filler has an average particle size of about 25 μm to about 110 μm, and the second filler has an average particle size of about 5 μm to about 10 μm.

32. The method of any one of claims 29 to 31, wherein the mixture comprises about 10% to about 50% by volume of the mixture of the first filler, and From about 0.1% to about 20% by volume of the mixture of the second filler.

33. The method of any one of claims 29 to 32, wherein the first filler is comprised of iron and the second filler is comprised of tungsten.

34. The method of any one of claims 29 to 33, wherein the branched condensation polymer is comprised of one or more of polyamides, polyesters, polyacetals, and polycarbonates and chain breaking / extending compounds.

35. The method of claim 34, wherein the branched condensation polymer is a polyamide.

36. The method of 35, wherein the branched condensation polymer comprises a 6 / 66 / 12 polyamide.

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