STYRENE-ETHYLENE BLOCK COPOLYMER

Polylphenylene oxide) Styrene-ethylene block copolymer... 

Styrene-butadiene block copolymer Styrene-isoprene block copolymer Styrene-ethylene block copolymer Styrene-butylene block copolymer... 

Dipolystyryl aluminum chloride, prepared by stoichiometric reaction of 1 mol of AICI3 and 2 mol of living polystyrene, is used together with titanium halide catalyst to synthesize styrene-ethylene block copolymers (189). 

Styrene block copolymer Styrene-ethylene block (copolymer) Styrene maleic anhydride Sheet molding compound... 

The effect of blending LDPE with EVA or a styrene-isoprene block copolymer was investigated (178). The properties (thermal expansion coefficient. Young s modulus, thermal conductivity) of the foamed blends usually lie between the limits of the foamed constituents, although the relationship between property and blend content is not always linear. The reasons must he in the microstructure most polymer pairs are immiscible, but some such as PS/polyphenylene oxide (PPO) are miscible. Eor the immiscible blends, the majority phase tends to be continuous, but the form of the minor phase can vary. Blends of EVA and metallocene catalysed ethylene-octene copolymer have different morphologies depending on the EVA content (5). With 25% EVA, the EVA phase appears as fine spherical inclusions in the LDPE matrix. The results of these experiments on polymer films will apply to foams made from the same polymers. 

HMX HMX HMX HMX HMX HMX HMX HMX HMX HMX HMX HMX HNS NTO NTO/HMX NTO/HMX NTO/HMX PETN PETN PETN PETN PETN PETN PETN PETN PETN PETN RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX TATB/HMX Cariflex (thermoplastic elastomer) Hydroxy-terminated polybutadiene (polyurethane) Hydroxy-terminated polyester Kraton (block copolymer of styrene and ethylene-butylene) Nylon (polyamide) Polyester resin-styrene Polyethylene Polyurethane Poly(vinyl) alcohol Poly(vinyl) butyral resin Teflon (polytetrafluoroethylene) Viton (fluoroelastomer) Teflon (polytetrafluoroethylene) Cariflex (block copolymer of butadiene-styrene) Cariflex (block copolymer of butadiene-styrene) Estane (polyester polyurethane copolymer) Hytemp (thermoplastic elastomer) Butyl rubber with acetyl tributylcitrate Epoxy resin-diethylenetriamine Kraton (block copolymer of styrene and ethylene-butylene) Latex with bis-(2-ethylhexyl adipate) Nylon (polyamide) Polyester and styrene copolymer Poly(ethyl acrylate) with dibutyl phthalate Silicone rubber Viton (fluoroelastomer) Teflon (polytetrafluoroethylene) Epoxy ether Exon (polychlorotrifluoroethylene/vinylidine chloride) Hydroxy-terminated polybutadiene (polyurethane) Kel-F (polychlorotrifluoroethylene) Nylon (polyamide) Nylon and aluminium Nitro-fluoroalkyl epoxides Polyacrylate and paraffin Polyamide resin Polyisobutylene/Teflon (polytetrafluoroethylene) Polyester Polystyrene Teflon (polytetrafluoroethylene) Kraton (block copolymer of styrene and ethylene-butylene)... 

Chiu, H.-T. Chiu, W.-M. The toughening behavior in propylene-ethylene block copolymer filled with carbon black and styrene-ethylene butylene-styrene triblock copolymer. Mater. Chem. Phys. 56, 108-115 (1998). 

The following TPs are the main thermoforming materials processed high-impact and high-heat PS, HDPE, PP, PVC, ABS, CPET, PET, and PMMA. Other plastics of lesser usage are transparent styrene-butadiene block copolymers, acrylics, polycarbonates, cellulosics, thermoplastic elastomers (TPE), and ethylene-propylene thermoplastic vulcanizates. Coextruded structures of up to seven layers include barriers of EVAL, Saran, or nylon, with polyolefins, and/or styreneics for functional properties and decorative aesthetics at reasonable costs.239-241... 

Studies of ethylene-vinyl aromatic monomer polymerizations continue to be published. Chung and Lu reported the synthesis of copolymers of ethylene and P-methylstyrene [28] and the same group extended these studies to produce and characterize elastomeric terpolymers which further include propylene and 1-octene as the additional monomers [29,30]. Returning to the subject of alternative molecular architectures for copolymers, Hou et al. [31] has reported the ability of samarium (II) complexes to copolymerize ethylene and styrene into block copolymers. 

Poly(styrene-6-ethylene-co-butylene-/)-styrene) (SEBS) block copolymers... 

The hydrophobic polyurethane block copolymer was chosen because phase-separated samples had been shown by an in vitro assay to exhibit a greater platelet adhesion from human blood than samples having a mixed, nonphase-separated structure (7). The hydrophobic styrene-butadiene-styrene (SBS) block copolymer was chosen because of the ease with which the morphology could be controlled (8). The block copolymer having hydrophilic blocks of poly(ethylene oxide) and hydrophobic polystyrene blocks (PS-PEO) was chosen to examine the effect of the more hydrophilic blocks on the protein interaction. 

However, poor compatibility has not allowed for commercial utility in a non-oriented form. The addition of a styrene/ethylene-butylene/ styrene SEES block copolymer to blends of these polyolefins and polystyrene has been noted to yield good mechanical compatibiliza-tion [Schwarz et al., 1988], but only limited commercial activity has resulted probably due to economic considerations. 

A comparative study of MAH and diethyl maleate grafting—initiated by DCP—to styrene-(ethylene-butylene)-styrene triblock copolymer (SEES) and PS blended with a random ethylene-1-butene copolymer has been described elsewhere (66). The weight ratio of PS to PO components in the block copolymer was the same as in the blend (20% PO and 80 wt% PS). The analysis of the functionalized PS/PO blend—after PS had been extracted in a solvent—showed that the monomer was grafted only to the PO component. Considering that the PS/ PO blend and SEES have quite similar phase and molecular structures, it was concluded that in styrene-containing block copolymers only aliphatic blocks become functionalized. 

Melt adhesives are based on thermoplastics, but usually contain a number of other components. The most commonly used melt adhesives are based on ethylene-vinyl acetate (EVA) copolymers, but polyethylene, polyesters, polyamides, and thermoplastic rubbers (e.g., styrene-butadiene block copolymers) are also used (see Adhesive Bonding of Plastics in Chapter 2). 

Figure 5-34. Morphology of biblock poly (styrene- -ethylene oxide) copolymers cast from nitromethane (N) or butyl phthalate (B). —, Poly(styrene) blocks, —, poly(ethylene oxide) blocks (after C. Sadron).

Similar block copolymers have also been prepared by coupling methyl methacrylate macroanions and suitably terminated poly(ethylene oxide)( )and by the initiation of methyl and ethyl methacrylate by alkali metal alkoxides of poly(ethylene oxide)( 3). styrene containing block copolymers have also been produced( ). In the former plus latter techniques the ester containing block segments were subsequently hydrolyzed to methacrylic acid thus making them water soluble. 

Orientations in elongated mbbers are sometimes regular to the extent that there is local crystallization of individual chain segments (e.g., in natural rubber). X-ray diffraction patterns of such samples are very similar to those obtained from stretched fibers. The following synthetic polymers are of technical relevance as mbbers poly(acrylic ester)s, polybutadienes, polyisoprenes, polychloroprenes, butadiene/styrene copolymers, styrene/butadiene/styrene tri-block-copolymers (also hydrogenated), butadiene/acrylonitrile copolymers (also hydrogenated), ethylene/propylene co- and terpolymers (with non-conjugated dienes (e.g., ethylidene norbomene)), ethylene/vinyl acetate copolymers, ethyl-ene/methacrylic acid copolymers (ionomers), polyisobutylene (and copolymers with isoprene), chlorinated polyethylenes, chlorosulfonated polyethylenes, polyurethanes, silicones, poly(fluoro alkylene)s, poly(alkylene sulfide)s. 

Semicrystalline ethylene-propylene copolymer, EP, was blended with amorphous EP and inorganic filler. The blends had good processability, mechanical properties, and impact strength. In the Mitsubishi patent, crystalline EP was blended with styrene-isoprene block copolymer, 5-30 wt% SIS, and polystyrene, 3-5 wt% PS, to give good paintability... 

Thermoplastic polyolefin (TPO) is a generic name that refers to polyolefin blends usually consisting of some fraction of polypropylene (PP), polyethylene (PE) or polypropylene block copolymer (PP-b-EP or BCPP ), and a thermoplastic olefinic rubber, with or without a mineral reinforcing filler such as talc or wollastonite. Common rubbers include ethylene propylene rubber (EPR), EPDM rubber, ethylene-octene (EO) copolymer mbber, ethylene-butadiene (EB), and styrene-ethylene-butadiene-styrene (SEBS) block copolymer rubbers. Currently, there are a great variety of commercial polypropylene homopolymers, PP block copolymers, and olefinic rubbers available to make a wide range of TPO blends with densities ranging from 0.92 to 1.1. 

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