Abstract: A thermoplastic vulcanizate (TPV) is produced by melt blending until the volume fraction of dispersed rubber particles is greater than 0.5 preferably from 0.55 to 0.95, the remaining being the dispersed continuous plastic phase in a manner so as to develop a morphology which generates optimum elastic recovery. The majority (by volume) of large rubber particles are adjacent a small particle which is separated from one or more large particles by a critically thin, less than 0.1 $G(m)m thick, ligament of deformable plastic. When the majority of large particles evidence this morphology, as seen in a transmission electron microscope (TEM) photomicrograph, the TPV exhibits unexpectedly higher elastic recovery than if the ligaments were thicker. The foregoing is simulated in a micromechanical model which confirms, and in retrospect, predicts the observed actual elastic recovery of the TPV.

Abstract: A thermoplastic vulcanizate (TPV) from a blend of a first thermoplastic polyolefin, a second thermoplastic olefin and a rubber is described. The rubber is crosslinked with a hydrosilylation crosslinking agent. The second polyolefin includes at least one OR group pendant to a Si atom chemically attached via one or more intermediate molecules to said second polyolefin. R can be hydrogen or an alkyl of 1 to 8 carbon atoms. The OR groups can react with the hydrosilylation catalyst to reduce the compression set of the TPV.

Abstract: A process for forming a thermoplastic vulcanizate compromising the steps of dynamically vulcanizing a rubber within a blend that comprises the rubber and a thermoplastic polymer, where said step of vulcanizing is carried out by using a phenolic resin in the presence of a catalyst system formed by combining a metal halide and a metal carboxylate. Also, a thermoplastic vulcanizate having low moisture pick-up with a technologically useful cure.

Abstract: Random thermoplastic ethylene copolymers can be used to increase the elongation to break and toughness of thermoplastic vulcanizates. Polypropylene is a preferred thermoplastic phase. The rubber can be olefinic rubbers. Random thermoplastic ethylene copolymers are different from Ziegler-Natta ethylene copolymers as the compositional heterogeneity of the copolymer is greater with Ziegler-Natta copolymers. This difference results in substantial differences in properties (elongation to break and toughness) between thermoplastic vulcanizates modified with random thermoplastic ethylene and those modified with Ziegler-Natta ethylene copolymers. An increase in elongation to break results in greater extensibility in the articles made from a thermoplastic vulcanizate.

Abstract: A method for the dynamic vulcanization of polymer blends made by solution polymerization in series reactors. The polymer blends are mixed under conditions of heat and shear, and a curing agent is added to at least partially cross-link one of the blend components.

Abstract: A polar thermoplastic and acrylate or ethylene acrylate based polar rubbers form a useful thermoplastic vulcanizate when the rubber is selectively cured with curatives which do not affect the polar thermoplastic and do not generate volatile organics. Examples of thermoplastics include aromatic polyesters, polycarbonates, poly(phenylene oxide), or combinations thereof. Examples of curatives include compounds with a multifunctional oxazoline, oxazine or imidazoline, which can react with functional groups such as carboxylic acid groups on the rubber.

Abstract: Random propylene thermoplastic copolymers can be used to increase the elongation to break and toughness of thermoplastic vulcanizates. Semi-crystalline polypropylene is a preferred thermoplastic phase. The rubber can be olefinic rubbers. Random thermoplastic polypropylene copolymers are different from conventional Ziegler-Natta propylene copolymers as the compositional heterogeneity of the copolymer is greater with Ziegler-Natta copolymers. This difference results in substantial differences in properties (elongation to break and toughness) between thermoplastic vulcanizates modified with random thermoplastic propylene copolymers and those modified with conventional Ziegler-Natta propylene copolymers. An increase in elongation to break results in greater extensibility in the articles made from a thermoplastic vulcanizate.

Abstract: In the preparation of thermoplastic elastomers by hydrosilylation crosslinking of the elastomeric component, the use of an elastomer containing a non-conjugated diene and having a Mooney viscosity within the MST range of 45 to 100 provides products with a high level of crosslinking and an improved combination of physical properties. This improvement is obtained even at low concentrations of hydrosilylation catalyst.

Abstract: Random propylene thermoplastic copolymers can be used to increase the elongation to break and toughness of thermoplastic vulcanizates. Semi-crystalline polypropylene is a preferred thermoplastic phase. The rubber can be olefinic rubbers. Random thermoplastic polypropylene copolymers are different from conventional Ziegler-Natta propylene copolymers as the compositional heterogeneity of the copolymer is greater with Ziegler-Natta copolymers. This difference results in substantial differences in properties (elongation to break and toughness) between thermoplastic vulcanizates modified with random thermoplastic propylene copolymers and those modified with conventional Ziegler-Natta propylene copolymers. An increase in elongation to break results in greater extensibility in the articles made from a thermoplastic vulcanizate.

Abstract: Low oil swell, non sticky readily processable carboxylated nitrile rubber-thermoplastic polyurethane vulcanizate compositions have increased upper service temperature over comparable thermoplastic polyurethanes. The compositions of the present invention are made utilizing a processing aid, for example, maleated polyolefins and addition type curing agents such as bisoxazolines or bisimidazolines. The compositions generally contain thermoplastic polyurethane as a continuous phase with the carboxylated nitrile rubber being dispersed therein.

Abstract: A thermoplastic vulcanizate composition containing a thermoplastic and a functionalized copolymer of para-alkylstyrene-isoolefin is free radically cured, as for example, with a peroxide to yield a product having low impurities and good clarity. The thermoplastic typically can be a polyolefin.

Abstract: Thermoplastic elastomer compositions which have good high temperature end use and good oil swell resistance are made by blending a high melting thermoplastic polymer containing a non-polar rubber and a polar rubber. Alternatively, a high melting thermoplastic polymer containing a non-polar rubber or a polar rubber or both is blended with a polyolefin thermoplastic polymer containing a non-polar rubber, or a polar rubber, or both. The composition is dynamically vulcanized. The cured multi-component thermoplastic elastomer compositions exhibit good end use properties such as hardness, tensile strength, modulus, flexibility.

Abstract: Thermoplastic vulcanizate blends are prepared from a semi-crystalline polymer and a rubbery copolymer derived from copolymerizing at least one alpha-olefin monomer and at least one cyclic olefin copolymer. The rubbery copolymer also includes repeat units from at least one polyene monomer. The polyene monomer provides residual unsaturation for crosslinking of said rubbery copolymer. Crosslinking the rubbery copolymer of the blend generally reduces tension set, compression set and oil swell in aliphatic solvents. The cyclic olefin monomer reduces oil swell in aliphatic oils.

Abstract: A blend of a semicrystalline polyolefin, a rubbery polymer containing repeat units from norbornene, and a polymeric compatibilizer is disclosed. This composition has reduced oil swell as compared to thermoplastic vulcanizates from a semicrystalline polyolefin and hydrocarbon rubbers.

Abstract: Low oil swell, processable carboxylated nitrile rubber thermoplastic vulcanizate compositions having high melting points are made utilizing a processing aid, for example, maleated polyethylene, and addition type curing agents such as bisoxazolines or bisimidazolines. The compositions generally contain polar thermoplastic high melting point crystalline polymers such as polyester as a continuous phase with the carboxylated nitrile rubber being dispersed therein.

Abstract: Thermoplastic elastomer compositions which have good high temperature end use and good oil swell resistance are made by blending a high melting thermoplastic polymer containing a non-polar rubber and a polar rubber. Alternatively, a high melting thermoplastic polymer containing a non-polar rubber or a polar rubber or both is blended with a polyolefin thermoplastic polymer containing a non-polar rubber, or a polar rubber, or both. The composition is dynamically vulcanized. The cured multi-component thermoplastic elastomer compositions exhibit good end use properties such as hardness, tensile strength, modulus, flexibility.

Abstract: A thermoplastic elastomer composition has a plastic phase or matrix of an engineering thermoplastic such as a polyamide and a crosslinked phase of cured acrylic rubbers. The rubbers contain at least two functionalized acrylic rubbers wherein the functional group such as a carboxyl, an epoxy, or a hydroxyl can be the same or different. The curing agents generally react via covalent bonding with the reactive functional groups of the rubbers. The composition can be dynamically vulcanized and when one of the rubbers is a terpolymer of ethylene-alkyl acrylate-unsaturated carboxylic acid, the composition has a single low temperature brittle point.

Abstract: A thermoplastic elastomer composition has a plastic phase or matrix of an engineering thermoplastic such as an ester polymer and a crosslinked phase of cured acrylic rubbers. The rubbers are cured by a curing agent and contain at least two functionalized acrylic rubbers wherein the functional group such as a carboxyl, an epoxy, or a hydroxyl can be the same or different. The composition can be dynamically vulcanized and desirably when one of the functionalized acrylic rubbers is a terpolymer of ethylene-alkyl acrylate-unsaturated carboxylic acid, the composition has a single low temperature brittle point.

Abstract: The phenolic resin curatives used as a curative in thermoplastic elastomers are attributed with staining of painted surfaces which physically contact the thermoplastic elastomers. When the phenolic resin curatives are esterified (e.g., acetylated, tosylated, silylated or phosphorylated) before use as a curative, the amount of staining is reduced or staining is eliminated.

Abstract: Thermoplastic vulcanizates from semicrystalline polyolefins and blends of crosslinked rubbers are disclosed. The blends are a mixture of at least two rubbers. One rubber is a copolymer predominantly of C.sub.4 to C.sub.7 isomonoolefins (e.g. isobutylene), along with optional monomers of conjugated dienes and/or p-alkylstyrene. This copolymer is optionally halogenated. The second rubber is ethylene/propylene rubber, natural rubber or a rubber polymerized predominantly from a conjugated diene. Such rubbers include polybutadiene, nitrile rubber, butadiene-styrene copolymers or combinations thereof.