58 results about "Polymer morphology" patented technology

The spherical catalyst carrier is prepared with alcoholated magnesium chloride containing double-ether compound in emulsifying pelletizer. Liquid titanium halide compound is carried onto the spherical catalyst carrier to form spherical solid catalyst component in the presence of electron donor. In the X-ray diffraction spectrogram, the spherical solid catalyst component has diffraction peak in 13.3 deg of 2theta angle, strongest diffraction peak in 26.5 deg of 2theta angle and no characteristic diffraction peak of alpha-anhydrous MgCl2 in 15 deg of 2theta angle. The catalyst of the presentinvention has very high activity and may be used to produce polymer with good form, high apparent density and less fine powder. The catalyst is used in homopolymerization and copolymerization of olefin and suitable for various polymerization process.

The invention discloses an equivoluminal dipping loading method of non-metallocene olefin polymeric catalyst as well as application of copolymerizing course within two or more different olefins, which comprises the following steps: dissolving non-metallocene olefin polymeric catalyst in the solvent; mixing solution and carrier; stirring wet solid material evenly; drying; obtaining the load-typed non-metallocene olefin polymeric catalyst; making the solvent and carrier satisfy specific relationship.

A stent may be formed from a PLLA tubular polymer construct that is deformed in a blow mold. A desirable polymer morphology resulting in improved stent performance is obtained with a selected radial axial expansion ratio from about 20% to about 70%, a selected radial expansion ratio from about 400% to about 500%, a selected axial rate of deformation propagation at or about 0.3 mm/minute, a selected expansion pressure at or about 130 psi, and a selected expansion temperature that does not exceed 200 deg F. The tubular polymer construct may also be made of PLGA, PLLA-co-PDLA, PLLD/PDLA stereocomplex, and PLLA-based polyester block copolymer containing a rigid segment of PLLA or PLGA and a soft segment of PCL or PTMC.

The invention provides a drawn and/or crimped fiber comprising a biodegradable polymer, such as polylactic acid, wherein the drawn and/or crimped fiber exhibits a storage-stable tenacity that does not decrease from an initial tenacity upon manufacture by more than about 10% after storage for 120 days in ambient conditions. The polymer composition used to form the fiber may comprise a softening agent. The fiber can be a drawn and crimped bicomponent fiber that is helically self-crimped and which comprises a first biodegradable polymer component and a second biodegradable polymer component, wherein the first polymer component and the second polymer component exhibit different polymer morphology such that each polymer component will undergo a different extent of longitudinal shrinkage upon application of heat. The outer surface of the fiber may carry a water-repellant coating. The invention also provides a method of forming a drawn and/or crimped fiber exhibiting storage-stable tenacity.

Hot-curing structural adhesives with multiphase polymer morphology, wherein the binder matrix of the cured chemically reactive adhesive displays

• (a) a continuous phase containing a polymer P1 having a glass transition temperature of over 100° C.;
• (b) a heterodisperse phase consisting of individual continuous domains of a thermoplastic or elastomeric polymer P2 having a glass transition temperature of below −30° C. and an average particle size of between 0.5 and 50 μm, which itself contains separate phases of another thermoplastic or elastomeric polymer P3 having a glass transition temperature of below −30° C. and a size of between 1 nm and 100 nm, parts of which can be in aggregated form as larger agglomerates; and
• (c) another heterodisperse phase embedded in the continuous phase and consisting of domains of the polymer P3, at least parts of which have an average particle size of between 1 nm and 50 nm, wherein P3 is not identical to P2; are suitable as high-strength, impact resistant structural adhesives, for internal stiffeners for cavities in automobile construction and for the production of reinforcing coatings for thin-wall sheet components.

The two stage production of clear, low-haze, injection stretch blow molded polypropylene container articles is disclosed. In the first processing stage, a preform article is manufactured on an injection molding machine. In a second and subsequent step, which may occur remotely from apparatus used in the first step, the preform article is heated and stretch blown into a container. The process may employ the selection of processing parameters to produce preform articles that facilitate stretch blow molding at relatively high rates of speed, while still maintaining an appropriate polypropylene polymer morphology that results in clear, low haze containers.

The two stage production of clear, low-haze, injection stretch blow molded polypropylene container articles is disclosed. In the first processing stage, a preform article is manufactured on an injection molding machine. In a second and subsequent step, which may occur remotely from apparatus used in the first step, the preform article is heated and stretch blown into a container. The process may employ the selection of processing parameters to produce preform articles that facilitate stretch blow molding at relatively high rates of speed, while still maintaining an appropriate polypropylene polymer morphology that results in clear, low haze containers, with ultraviolet light protection. In some applications, the resulting containers are capable of withstanding hot fill operations.

The invention belongs to the field of modern isolation analysis materials science and engineering, it relates to preparation method and application of microwave assistant molecular print magnetic microsphere, the procedure as follows: adopting microwave chemical reactor, taking nanometer magnetic fluid as magnetic nuclei, by cleaning and external modification, ultrasound detracting to water; mounted pattern molecule and functional monomer self-assembly; adding polymeric liquor by step, cross link agent and initiator, making it mixes and separates with magnetic fluid fully by stirring of machine, microwave procedure controlled temperature and heats up, until raising polymerization; Magnetic separates the foregoing magnetic microsphere, removing mounted pattern molecule, vacuum drying, aging. The molecular print magnetic microsphere has not only recognize ability of mounted pattern molecule and its analogue, but also has the approved characteristic of 'gathering hyphen recycle', the process of preparation heats up with microwave, decreasing the time of print aggregation, improving homogeneity and print efficiency of polymer form. The molecular print magnetic sphere applies to gather, isolate and analysis of structure analogue in the environmental sample, eatable etc complex samples.

The invention relates to a supported metallocene catalyst. The catalyst contains 5-20wt% of Al, and 0.01-0.3wt% of a transition metal. The catalyst can be used for homopolymerization and copolymerization reactions of olefin, a polymer prepared in the invention has good form and is not sticky to kettles, and the olefin polymerization catalysis activity is not lower than 1000 times/h. The invention also relates to a preparation method of the supported metallocene catalyst. The alkylaluminoxane load rate and the metallocene compound load rate of the supported metallocene catalyst prepared through the method are greater than 70wt% respectively. The preparation method has the advantages of simple process, short production period, efficient preparation of the supported metallocene catalyst under mild reaction conditions, small loss of alkylaluminoxane in the loading process, and production cost reduction.

The invention relates to a metallocene catalyst composition. The catalyst composition contains a polymer, and alkylaluminoxane and a metallocene compound supported metallocene catalyst component which are supported on a carrier, wherein a weight ratio of the polymer to the supported metallocene catalyst component is 0.1-10:1, and the alkylaluminoxane loading rate and the metallocene compound loading rate are respectively greater than 70wt%. The catalyst can be used for homopolymerization and copolymerization reactions of olefin, the olefin polymerization reaction catalysis activity is high, and a polymer prepared in the invention has good form and few fine powders and is not sticky to kettles. The invention also relates to a preparation method of the metallocene catalyst composition. The method has the advantages of simple process, short production period, efficient preparation of metallocene catalysts under mild reaction conditions, small loss of alkylaluminoxane in the loading process, and production cost reduction.

The invention relates to a loaded metallocene catalyst. The load rates of alkylaluminoxane and a metallocene compound of the catalyst are greater than 70% (by weight). The catalyst is relatively high in activity, and can be used for homopolymerization and copolymerization reactions of olefins and does not fall in the polymerization process. The prepared polymer is good in shape and less in polymer fine powder and is not sticky to a kettle. The invention further relates to a method for preparing the loaded metallocene catalyst. The method is simple in process and short in production period, and can be used for efficiently preparing the loaded metallocene catalyst under a mild reaction condition. The loss of alkyl aluminum in the loading process is less, the production cost is low, and the prepared catalyst is high in load rate and good in polymerization reaction activity.

The invention relates to a metallocene catalyst system for olefin polymerization and a preparation method thereof. The catalyst is mainly prepared from an organic high-molecular polymer carrier, a co-catalyst and a metallocene compound, wherein the carrier is styrene-divinyl benzene-hydroxyethyl methylacrylate terpolymer; a molar ratio of aluminum Al in the co-catalyst to metal atom M in the metallocene compound is 50-300; and based on the molar percentage of aluminum Al, each gram of organic high-molecular polymer carrier contains 1-12mmol of co-catalyst. The preparation method mainly comprises the steps of synthesizing the organic high-molecular polymer carrier, and loading the metallocene catalyst. The preparation method is simple and environment-friendly, the prepared catalyst and polymer have good shape since a novel organic porous carrier is adopted, and the catalyst has relatively high activity.

Disclosed are hydrogels polymerized with a biofunctional moiety, biodegradable and permanent, designed to be implantable in a mammalian body and intended to block or mitigate the formation of tissue adhesions. The hydrogels of the present invention are characterized by comprising four structural elements: a) a polymeric backbone which defines the overall polymeric morphology, b) linkage groups, c) side chains, and d) biofunctional end groups. The hydrophobicity of the various structural elements are chosen to reduce tissue adhesion and enhance the biofunctional aspect of the end groups. The morphology of these polymers are typically of high molecular weight and have shape to encourage entanglement. Useful structures include branching chains, comb or brush, and dendritic morphologies.

Olefin polymerization in the presence of heterogeneous supported catalysts is improved by incorporating into the supported catalyst a unifunctional hydrophobic tether comprising a hydrophobic portion containing no basic nitrogen and a univalent reactive group. The unifunctional hydrophobic tether reduces fouling and sheeting in gas phase polymerization processes and improves polymer morphology and bulk density in slurry polymerization processes, while substantially maintaining or enhancing catalyst polymerization activity.

The invention relates to application of a catalyst loaded with alpha-diimine metal complex to olefin polymerization. Hydroxyl at a diimine ligand can react with reactive groups on a chemically modified carrier to form covalent bonds, so that the alpha-diimine compound is firmly supported on the carrier by chemical bonding and is prevented from being detached from the carrier. The alpha-diimine exhibits high-temperature-resistant catalytic activity in the presence of a small steric hindrance group. Meanwhile, an aromatic group on an imine group in the alpha-diimine compound can be arbitrarily changed as needed. Moreover, the preparation of the alpha-diimine ligand is simple, thereby facilitating application of the alpha-diimine metal complex to polymerization of olefins. The load of the alpha-diimine metal complex can improve the problems of adherence to a kettle, control difficulty on polymer morphology, large usage amount of a co-catalyst, bad thermal stability and the like of a homogeneous alpha-diimine late transition metal catalyst in actual application in the prior art.

A real-time observing system for small-angle laser diffusion of slit in ultrasonic vibration field is composed of a die wound by heating winding and with lower slit and upper material cavity, temp sensor, displace sensor installed to plunger rod in said cavity ultrasonic generator, laser device, photoelectric detector, amplifier, temp control system and microcomputer.

This invention discloses one chromatography image test method in enclosed melt materials, which comprises the following steps: shaping space chromatography image; aim chromatography image extracting and pre-processing; aim image property extracting; aim image property identifying and measuring for melt materials enclosed. This invention solves the problems of difficult identification and measurement to provide one technique method for polymer shaping mechanism.