Abstract: A method of producing a polymer or a stellar polymer which comprises polymerizing a vinyl monomer in the manner of living radical polymerization and adding a compound having two or more polymerizable carbon-carbon double bonds at the end point of the polymerization.

Abstract: A process for the preparation of a blend of ABS polymers is disclosed. The invention comprises introducing a core/shell grafted rubber in the form of powder (crumb) to at least one stage of the continuous mass polymerization process for making an ABS polymer.

Abstract: The present invention discloses a process for manufacturing monovinylaromatic compounds containing an elastomer to provide increased toughness and strength. One particular embodiment of the invention discloses a process for manufacturing high impact polystyrene wherein styrene monomer containing a dissolved polybutadiene rubber is flowed into an elongated upflow stirred reactor containing three reaction zones, wherein the styrene and rubber are polymerized past the inversion point, then discharged to at least one additional reactor to continue their conversion to polymer.

Abstract: A process for producing impact-resistant moulding compositions, which is characterised in that a monomer mixture comprising 90 to 20 parts by weight of an aromatic monoalkenyl compound, 10 to 50 parts by weight of an ethylenically unsaturated nitrile, 0 to 30 parts by weight of other copolymerisable compounds is polymerised by a radical mechanism in the presence of 15 to 50 parts by weight, per 100 parts by weight of monomers, of a soluble, gel-free butadiene polymer, and in the presence of 50 to 200 parts by weight, per 100 parts by weight of monomers, of a solvent, wherein the solvent is selected from the group comprising an aliphatic (C1-C8) or cycloaliphatic alcohol, ketone, ether, ester, nitrile (A) or mixtures thereof or a mixture of (A) with an aliphatic (C4-C10), cycloaliphatic or aromatic hydrocarbon (B) in an A:B weight ratio of 100:0 to 30:70, and the polymerisation is conducted as far as a polymer content of the total mixture of 30 to 70% by weight, with thorough mixing and optionally with

Abstract: A process for preparing a solution of high molecular weight polymers of conjugated dienes in a vinylaromatic hydrocarbon by anionic polymerization of the diene in the presence of an alkyllithium as catalyst and a process for preparing impact-modified polymers of vinylaromatic compounds is described. The first process comprises firstly polymerizing the diene in solution in an aromatic hydrocarbon which is free of ethylenic double bonds to a molecular weight below about 105, then adding a trialkylaluminum in a molar excess relative to the alkyllithium, diluting the solution obtained with the vinylaromatic compound and then coupling the polydiene with a polyepoxide or an alkyl (meth)acrylate to give a high molecular weight polymer. The solution obtained in this way is further processed to give an impact-modified polymer of a vinylaromatic hydrocarbon by polymerizing the solution prepared as described, if desired after addition of further amounts of a vinylaromatic compound, in a manner known per se.

Abstract: The present invention provides a solvent exchange column for continuously exchanging styrene monomer with the solvent used to produce polybutadiene and a method of use therefor. The solvent exchange column includes an exchange plate support structure coupled to and supporting spaced apart exchange plates, wherein each of the exchange plates has holes located therein to allow a passage of fluid therethrough. The solvent exchange column further includes a vapor ventilation system for allowing the volatized solvent to exit the solvent exchange column.

Abstract: A hydrogenated block copolymer has at least two polymer blocks A each having an aromatic vinyl hydrocarbon compound monomer unit and at least two hydrogenated polymer blocks B each having a hydrogenated butadiene monomer unit. At least 90% of olefinically unsaturated double bonds in the polymer blocks mainly having a butadiene monomer unit before hydrogenation have been hydrogenated. At least one of the locks at the terminal of the hydrogenated block copolymer is the polymer block B. The proportion of the terminal polymer blocks B in the hydrogenated block copolymer is 0.1 wt % to 9.1 wt %. The proportion of the aromatic vinyl hydrocarbon compound in the hydrogenated block copolymer is 25 wt % to 80 wt %. The 1,2-bond content of the polymer blocks having a butadiene monomer unit before hydrogenation averages 60 mol % to 99 mol %. The resulting resin composition improves the balance among the appearance of its molded article, tensile elongation at break and moldability.

Abstract: A hydrogenated block copolymer which comprises at least two polymer blocks A each mainly comprising an aromatic vinyl hydrocarbon compound monomer unit and at least two hydrogenated polymer blocks B each mainly comprising a butadiene monomer unit, at least 90% of the olefinically unsaturated double bonds in said polymer block mainly comprising a butadiene monomer unit before hydrogenation having been hydrogenated, wherein at least one of the block at the terminal of the hydrogenated block copolymer is the polymer block B, wherein the proportion of the terminal polymer blocks B in the hydrogenated block copolymer is at least 0.1 wt % but less than 9.

Abstract: Radial block copolymers that exhibit one phase melt behavior at a temperature below the degradation temperature of the radial block copolymer. The radial block copolymers have a plurality of arms, wherein each arm has a numerical average molecular weight of from about 5,000 to about 30,000, each arm includes a monoalkenyl aromatic hydrocarbon block and a hydrogenated conjugated diolefin block, and the monoalkenyl aromatic hydrocarbon is preferably present in an amount of from about 10 wt % to about 40 wt % of the radial block copolymer. Also disclosed is a process for preparing the one phase melt block copolymers.

Abstract: The present invention relates to a transparent butadiene-based rubber-reinforced resin produced by graft-polymerizing monomer components (b) comprising as main components an aromatic vinyl compound, a vinyl cyanide compound and an acrylic or methacrylic acid ester in the presence of particles of a butadiene-based rubber (a), said butadiene-based rubber-reinforced resin comprising, when observed by an electron microscope, a rubber phase having an average particle size of 150 to 350 nm and containing particles having a particle size of less than 150 nm in an amount of not more than 30% by weight and particles having a particle size of more than 350 nm in an amount of not more than 30% by weight; and containing acetone solubles having an intrinsic viscosity [&eegr;] of 0.2 to 0.4 dl/g when measured at 30° C. in methyl ethyl ketone.

Abstract: In a process for the homopolymerization of vinylaromatic monomers or the copolymerization of vinylaromatic monomers and dienes, the monomers are polymerized in the presence of at least one alkali metal organyl, at least one magnesium organyl and at least one aluminum organyl. The invention also provides an initiator composition for carrying out the process.

Abstract: Disclosed are rubber-modified monovinylidene aromatic polymers with improved toughness and rigidity as well as a process for the preparation thereof. The polymer comprises: a) a monovinylidene aromatic polymer matrix, b) rubber particles dispersed therein, characterized in that the rubber particles are produced from a diene rubber having I) from 20 to 80 percent, based on the total weight of said rubber particles, of a high solution viscosity component having a viscosity value ranging from 110 to 500 centipoise and II) from 80 to 20 percent, based on the total weight of said rubber particles, of a low solution viscosity component having a viscosity value ranging from 1 to 100 centipoise, further characterized in that the ratio of solution viscosity of high solution viscosity component to the solution viscosity of low solution viscosity ranges from 1.

Abstract: A block copolymer comprising at least three consecutive conjugated diene/monovinylarene tapered blocks is provided. Other aspects of this invention include a polymerization process for preparing the block copolymer and polymer blends comprising the block copolymer. The block copolymer and polymer blends exhibit excellent optical and mechanical properties.

Abstract: The present invention relates to star-block interpolymers having the following structure (X—Y)n—C, wherein X represents a random copolymer block derived from conjugated diene and monovinyl aromatic monomer; Y represents a polyconjugated diene block; C represents a residue derived from a multifunctional lithium based initiator; and n represents the functionality of the initiator and has a value of not less than 3; and preparation of the same. The star-block interpolymers according to the present invention have in the same molecule both a random copolymer block derived from conjugated diene and monovinyl aromatic monomer and a rubber block selected from the group consisting of a homopolymer block derived from conjugated diene, a tapered copolymer block derived from conjugated dienes, a random copolymer block derived from conjugated dienes and combinations thereof, and hence possess excellent properties of the both kinds of rubbers, and can be used widely as elastomeric materials.

Abstract: The present invention discloses processes and apparatus for the efficient and rapid conversion of an elastomeric monomer to a polymerized elastomer, and conjointly, reaction of the resultant rubbery polymer into a monovinylaromatic polymerization reaction to form a rubber-modified polymer; and more specifically teaches a method of polymerizing butadiene and reacting it with styrene monomer to form a transparent rubber-modified impact-resistant polystyrene material exhibiting elastomer concentrations that range from as low as 6 weight percent or lower, to as high as about 50 percent.

Abstract: A block copolymer comprising at least three consecutive conjugated diene/monovinylarene tapered blocks is provided. Other aspects of this invention include a polymerization process for preparing the block copolymer and polymer blends comprising the block copolymer. The block copolymer and polymer blends exhibit excellent optical and mechanical properties.

Abstract: A process of preparing a diblock/triblock composition in a single reaction vessel includes reacting a first monomer, such as styrene, with a first portion of an anionic catalyst in a suitable solvent to form a first polymer block of the triblock. A second step includes adding a second monomer, such as butadiene (when the first monomer is styrene). This forms a second block of the triblock and a first block of the diblock. A further addition of the first monomer completes the diblock and triblock interpolymers. At least a portion of the diblock and/or triblock interpolymers are functionally terminated with a functional terminating agent, such as cyclohexene oxide or isopropanol, to provide the blocks with a functional group. The functional group and the proportion of the interpolymers functionally terminated are selected to provide desired adhesive properties for a particular application.

Abstract: A thermoplastic molding composition containing 1 to 99 parts by weight of aromatic polycarbonate or polyester carbonate and 1 to 99 parts by weight of at least one graft polymer prepared by solution polymerization is disclosed. The graft polymer is characterized in having rubber content of 20 to 50 wt. % and in that the average particle size of its rubber phase is 80 to 600 nm. The composition, which optionally contains additives, flameproofing agents and reinforcing agents, is characterized by its improved mechanical properties.

Abstract: A process is disclosed for manufacturing coupled radial block copolymers of the S—B—Li type having improved optical properties, which process utilizes coupling agents having from about 3 to about 7 epoxy groups per mole.

Abstract: An anionically polymerized impact-modified polystyrene has a yield stress of at least 24 MPa, measured at 23° C. to DIN 53455 and a hole impact strength of at least 11 kJ/m2, measured at 23° C. to DIN 53753, measured in each case on a specimen produced to ISO 3167. A preparation process is described.

Abstract: The present invention relates to a process for producing a rubber reinforced styrene-based resin, using a polymerization apparatus comprising: a prepolymerizer; mixing means and a circulating reactor connected with a circulation line; and a plug-flow type reactor, which process comprises: continuously feeding a stock solution into the prepolymerizer; feeding the prepolymerized liquid into the mixer; in this mixer, mixing the prepolymer liquid with circulated liquid that is circulated from the circulating reactor at a flow amount of from 0.5 to 3 times (circulation flow ratio: volume ratio) the flow amount of the prepolymer liquid fed from prepolymerizer into the mixing means; particulating and dispersing the rubbery polymer in the mixed liquid by mechanical shear force; and then feeding the polymer liquid into the plug-flow type reactor, to thereby effect a polymerization.

Abstract: A process for preparing impact-modified styrene polymers (HIPS) omprises anionic polymerization of styrene in the presence of a rubber in one or more polymerization reactors in succession. The rubber is prepared in solution in an immediately upstream process. The heat of polymerization is utilized to remove the solvent for the rubber, this solvent having a boiling point lower than those of styrene and ethylbenzene, from at least one of the polymerization reactors via distillation with distillative cooling, and the solvent is reintroduced into the process of rubber preparation.

Abstract: A process is disclosed for the continuous production of an ABS resin. The polymerization step comprises at least two substeps, one being a first-stage substep of forming particles of the rubbery polymer and the other a second-stage substep of adjusting the particle sizes of the particles. The first-stage substep is conducted in a polymerization system making use of a plug flow reactor or a batch polymerization reactor, and conducts polymerization at least until the particles are formed in the polymerization mixture. The second-stage substep increases a converted amount of the monomer component into the polymer compared with that in the particle forming substep and makes the particles smaller. A polycarbonate-ABS resin composition is also disclosed.

Abstract: A styrene resin is disclosed having excellent moldability and physical properties and is suited for recycling; and a thermoplastic polycarbonate composition with the styrene resin. The styrene resin contains 50 to 90 wt. % of a continuous phase component (S) composed of a copolymer of a styrene monomer, an unsaturated nitrile monomer; and 10 to 50 wt. % of a dispersed phase component on which said monomers have been grafted and which has occluded said copolymer. In the styrene resin, no triple chain unit AAA is detected from the unsaturated nitrite monomer component (A) in the continuous phase component (S) and a double chain unit AA amounts to 3% or less based on the whole units (A) detected.

Abstract: A process for interpolymerizing a vinyl aromatic hydrocarbon polymer and a block polymer is disclosed. The process includes the following steps: (a) forming a block polymer precursor of at least one polymeric block containing conjugated diene monomer contributed units in the presence of an anionic initiator and in an inert diluent, the block polymer precursor having living ends; and (b) thereafter adding to the block polymer precursor a charge of a vinyl aromatic hydrocarbon monomer and an additional charge of an anionic initiator to simultaneously form (1) a block polymer having a terminal block formed from the charge of vinyl aromatic hydrocarbon monomer attached to the block polymer precursor and (2) a poly(vinyl aromatic hydrocarbon) polymer interpolymerized with the block polymer. The practice of this process produces a vinyl aromatic hydrocarbon block terminated block polymer, such as SBS, interpolymerized with a polymer formed from vinyl aromatic hydrocarbon monomer, such as polystyrene.

Abstract: In a process for the preparation of block copolymers from vinylaromatic monomers and dienes, the monomers are polymerized in the presence of at least one alkali metal organyl or alkali metal alkoxide and at least one magnesium, aluminum or zinc organyl.

Abstract: The rubber-containing styrenic resin of the present invention comprises a styrenic resin matrix and a rubber component dispersed in particles. In the resin, the graft ratio of a styrenic monomer relative to the rubber component is not less than 1, the particle size of the dispersed rubber component is 0.1 to 3 &mgr;m, and the following equation (1) is satisfied: Mn=aT+b  (1) wherein Mn is the number average molecular weight of the matrix resin; T is the conversion of the styrenic monomer; a is a constant greater than 0; and b is a constant of 0 or greater. The rubber component may be a butadiene-series rubber. The particle-size distribution of the dispersed rubber component may have, for example, two peaks.

Abstract: The present invention is related to a bimodal rubber characterized in that the bimodal rubber is a composition of linear, and branched rubber molecules, and has a broad, yet monomodal Mw distribution and rubber modified polymers produced therefrom.

Abstract: In a process for increasing the elongation at break of moldings made from thermoplastic molding compositions comprising, based on the total of the amounts of components A and B and, where appropriate, C and/or D, the entirety of which gives 100% by weight,

Abstract: A thermoplastic resin composition comprises a thermoplastic resin (A) and graft copolymer particles (B) having a hollow rubber portion and graft chain, in which a volumetric proportion of hollow part in the hollow rubber portion of the graft copolymer particles is 1 to 70% by volume. The thermoplastic resin composition contains the thermoplastic resin and the graft copolymer particles in a weight ratio (A)/(B) of 2/98 to 100/1. The hollow part in the graft copolymer particle functions to further improve impact resistance.

Abstract: Disclosed is a polymer blend composition containing an aromatic carbonate polymer and a rubber-modified monovinylidene aromatic copolymer comprising a star-branched rubber and optionally, a linear rubber. The polymer blend compositions according to the invention have a desirable balance of processability and when molded, impact strength.

Abstract: Disclosed is a rubbery polymer comprising a conjugated diene polymer, and bonded thereto, a lithium-detached residue of a lithium-containing organic polymer used as a catalyst in the production of the conjugated diene polymer, wherein the lithium-containing organic polymer is obtained by reacting an organolithium compound with a first polymerizable material comprising at least one conjugated diene monomer and a second polymerizable material comprising at least one aromatic vinyl compound, which second polymerizable material contains at least one multi-vinyl aromatic compound having at least two vinyl groups, and wherein the lithium-containing organic polymer has a specific narrow molecular weight distribution.

Abstract: The anionic polymerization of dienes or copolymers of dienes and vinylaromatic monomers in a vinylaromatic monomer or monomer mixture to give homopolydienes or copolymers or mixed homopolydienes and copolymers is carried out in the presence of a metal alkyl or aryl of an element having a valence of at least two without addition of Lewis bases.

Abstract: This invention relates to a process for preparing rubber-modified aromatic vinyl resin compositions by polymerizing a raw material solution containing 3 to 20% by weight of rubbery polymer, 50 to 97% by weight of an aromatic vinyl monomer, and 0 to 30% by weight of a solvent until the conversion of said aromatic vinyl monomer falls in the range from 30 to 70%, adding a (meth)acrylate monomer or its mixture with other monomers to the reaction mixture so that the ratio by weight of the aromatic vinyl monomer in the reaction mixture to the (meth)acrylate monomer becomes 85/15 to 50/50, continuing the polymerization, and devolatilizing to remove the unreacted monomers, solvent, and the like. It is possible by this process to prepare easily and economically rubber-modified aromatic vinyl resin compositions of easy processability, good surface properties in respect to appearance and scratch resistance, and good balance between impact resistance and rigidity.

Abstract: The present invention provides resin materials for producing molded products endowed with excellent heat resistance, solvent resistance, toughness, tensile elongation, and transparency. Specifically, there are provided aromatic vinyl resin materials which have the following properties: Storage elasticity values G′(1.0) and G′(0.1) as measured at 300° C., a strain &ggr; of 20%, and a frequency of 1.0 Hz or 0.1 Hz satisfy the expression, log[G′(1.0)/G′(0.1)]≦0.6, the heat of fusion &Dgr;H as measured over the range 200-295° C. is 8 to 50 (J/g), and the 1H-NMR peak integrated values for the fraction corresponding to the temperature range of not lower than 50° C., as collected from temperature rising election fraction on the Soxhlet extraction residue by use of cyclohexane or o-dichlorobenzene, satisfy the relation [1.8-2.1 (ppm)]/[1.0-1.7(ppm))<0.49.

Abstract: Novel triblock copolymers are provided. The triblock copolymers have a midblock which is a copolymer of an isoolefin monomer and a vinyl aromatic monomer. Preferably, the midblock is a copolymer of isobutylene and alkylstyrene. The end blocks of the triblock copolymer are either a homopolymer of a vinyl aromatic monomer or a copolymer of two or more monomers selected from the group consisting of vinyl aromatics, styrene, methylstyrene, butylstyrene, halostyrene, p-allylstyrene and p-3-butenylstyrene. In addition, a process is provided for preparing a triblock copolymer.

Abstract: A method for preparing tapered block copolymers which are particularly useful for blend components in blends with polymers of styrene. In the first embodiment of this invention the copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; and (4) a coupling agent; to produce a polymodal tapered block copolymer. In a second embodiment of the invention tapered block copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjugated diene monomers; and (5) a coupling agent; to produce a polymodal tapered block copolymer.

Abstract: A method for preparing tapered block copolymers which are particularly useful for blend components in blends with polymers of styrene. In the first embodiment of this invention the copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; and (4) a coupling agent; to produce a polymodal tapered block copolymer. In a second embodiment of the invention tapered block copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjugated diene monomers; and (5) a coupling agent; to produce a polymodal tapered block copolymer.

Abstract: The present invention relates to a process for the manufacture of a composition comprising a vinylaromatic polymer and a rubber, wherein the polymerization stage is carried out in the presence of a stable free radical in a polymerization mixture. The presence of the stable free radical in the polymerization mixture makes its possible to increase the melt index and to influence the size of the rubber nodules in the final composition by generally increasing the fraction, by volume, of the rubbery phase and by widening the distribution of the size of these nodules. This is reflected by an improvement both in the melt index and in the impact strength of the final composition, which makes the latter an ideal composition for injection molding.

Abstract: The invention relates to a process for preparing a composition comprising a vinylaromatic polymer matrix and particles of rubber, which comprises a step of polymerizing at least one vinylaromatic monomer in the presence of a rubber comprising a group which generates a stable free radical. The process makes it possible to obtain morphologies other than salami morphologies, such as the labyrinth, onion or capsule morphology, with the aim, for example, of enhancing the gloss of the high-impact vinylaromatic polymer.

Abstract: In a process for preparing thermoplastic molding compositions by

Abstract: The dispersibility of the initial polystyrene block in forming a S-B-S type of copolymer is improved by first preparing a small block of homopolydiene such as homopolybutadiene as a dispersing agent. Onto this small block of homopolybutadiene, the first block of polystyrene is formed and affixed and thereby made dispersible in a mixture of alkanes and 15 to 60% by weight of cycloalkanes, preferably hexane and cyclohexane. After the preparation of the dispersing agent and the first styrene block, the remaining monomer charges to the reactor are fed in aliphatic hydrocarbon diluents, preferably hexane or technical hexane, thereby greatly reducing the final percentage of cycloalkanes including cyclohexane in the reactor to less than 25% of total dispersing medium. The block copolymers produced according to the present process display a narrow molecular weight distribution and improved tensile strength over block copolymers produced in the absence of the additional cycloalkanes in the solvent system.

Abstract: A hydrogenated block copolymer comprising: at least two polymer blocks A mainly comprising vinylaromatic hydrocarbon compound monomer units; and at least two polymer blocks B mainly comprising hydrogenated conjugated diene compound monomer units, in which at least 90% of the olefinically unsaturated double bonds contained in the unhydrogenated polymer block mainly comprising the conjugated diene compound monomer units is hydrogenated, wherein at least one of the terminal blocks is a polymer block B, the proportion of the terminal polymer block B in the hydrogenated block copolymer being 0.1% by weight or higher and lower than 9.1% by weight, and wherein the content of the vinylaromatic hydrocarbon compound units in the hydrogenated block copolymer is 12% by weight or higher and lower than 25% by weight. Also disclosed are a resin composition containing the hydrogenated block copolymer, and a molded article of the resin composition.

Abstract: Polymers are produced by alternate anionic polymerization of conjugated dienes and/or monomalkenyl arenes to form a living polymer chain, followed by precise incorporation of protected functional groups into that living polymer chain.

Abstract: Disclosed is a method for producing a rubber-modified styrenic resin. The method includes the steps of (a) producing a rubber solution by dissolving a rubber polymer in a vinyl monomer; (b) producing a rubber composition by continuously supplying the above rubber solution in a first reactor to polymerize the rubber polymer with the vinyl monomer at a reaction temperature of 120°-145° C. to perform phase inversion of the rubber polymer, thereby producing the polymer of conversion ratio of 10-40 wt %, and realized through 50-99% of rubber particles having an average particle diameter of 0.1-0.

Abstract: The present invention is a process for producing an anionic block polymer which comprises optionally anionically polymerizing styrene to form a homopolymer block of polystyrene, anionically polymerizing isoprene to form a hompolymer block of polyisoprene, and anionically copolymerizing styrene and isoprene to form a tapered copolymer block wherein the charge rate of both styrene and isoprene is from 15% to 75% by weight of the total tapered block monomer charge per minute and the weight ratio of the styrene to the isoprene is from 0.5:1 to 1.5:1. The process produces a unique polymer containing a tapered polymer block of styrene and isoprene which has a specific taper structure consisting of small segments of variable size of styrene monomers and isoprene monomers.

Abstract: The present invention is a blend of a monovinylidene aromatic polymer and a rubber modified monovinylidene aromatic polymer, which can be used to produce cost effective, transparent packaging that can be used in food packaging and non-food packaging markets, and can be produced using conventional thermoforming equipment. The blend comprises: a) from 50 to 88 wt. percent based on the total weight of the blend, of a monovinylidene aromatic polymer having a weight average molecular weight (Mw) of from 265,000 to 400,000 and a melt flow of less than 2.5 g/10 min.; and b) from 12 to 50 wt. percent based on the total weight of the blend, of a rubber modified monovinylidene aromatic polymer comprising a monovinylidene aromatic polymer matrix having rubber particles dispersed therein, wherein the rubber particles comprise, based on the total weight of the rubber particles, from 25 to 100 weight percent rubber particles having a capsule morphology and a volume average particle size of from 0.1 to 0.

Abstract: The use of microphase-separated polymer blends, comprising A-B-C triblockcopolymers containing an elastomeric middle block B and A′-C′ diblockcopolymers, for the preparation of permeable membranes.

Abstract: The invention relates to polybutadiene rubber wherein a molecular weight distribution curve of the rubber as determined by gel permeation chromatography (GPC) has 2 peaks attributable to a high molecular weight component and a low molecular weight component, a peak top molecular weight of the high molecular weight component and a peak top molecular weight of the low molecular weight component fall within ranges of from 100,000 to 1,500,000 and from 10,000 to 50,000, respectively, a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), Mw/Mn, falls within a range of from 4.5 to 14.5, and the content of a cis-1,4 structure is at least 80 wt. %, a high-impact aromatic vinyl resin composition comprising the polybutadiene rubber, and a preparation process of the resin composition.

Abstract: A thermoplastic molding composition comprising a grafted rubber and a copolymeric matrix is disclosed. The composition is characterized in that its grafted rubber includes a substrate, a first grafted phase and a subsequent grafted phase which are sequentially grafted to said substrate. The substrate which contains a crosslinked elastomer is grafted with a first grafted phase and with a subsequent grafted phase, both phases containing copolymers of at least one vinylaromatic monomer and at least one member selected from the group consisting of (meth)acrylonitrile and alkyl (meth)acrylate. The relative ratios of the monomers making up the copolymerized phases differ one from the other. The grafted rubber is present in particulate form having a weight average particle size of about 0.1 to 1.0 microns. The composition features improved impact strength and reduced opacity.