Abstract: Disclosed are bituminous blends having improved toughness and elasticity. The blends contain a bituminous binder and a tapered block copolymer formed from a monovinyl aromatic compound and a conjugated diene. Suitable tapered block copolymers include a tapered A-B-A type block copolymer of the A-t-B-t-A configuration, particularly those having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent, and tapered A-B-A type block copolymers of the A-B-t-A configuration having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent of the total monovinyl aromatic compound in the tapered block copolymer. Further disclosed is a method of making the blends. Further disclosed is a tapered A-B-A type block copolymer having an isolated monovinyl aromatic compound content of about 29 to about 75 weight percent.

Abstract: Novel diene/methacrylate ester block polymers, especially tertiary butyl methacrylate ester block polymers are uniquely prepared at near ambient temperatures and capable of being hydrolyzed and neutralized to yield the corresponding methacrylic acid and methacrylic acid salt (ionomer) derivatives. The compositions are usefully employed in the preparation of thermoplastic elastomers, adhesives and laminating films.

Abstract: Disclosed are bituminous blends having improved toughness and elasticity. The blends contain a bituminous binder and a tapered block copolymer formed from a monovinyl aromatic compound and a conjugated diene. Suitable tapered block copolymers include a tapered A-B-A type block copolymer of the A-t-B-t-A configuration, particularly those having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent, and tapered A-B-A type block copolymers of the A-B-t-A configuration having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent of the total monovinyl aromatic compound in the tapered block copolymer. Further disclosed is a method of making the blends. Further disclosed is a tapered A-B-A type block copolymer having an isolated monovinyl aromatic compound content of about 29 to about 75 weight percent.

Abstract: Disclosed are bituminous blends having improved toughness and elasticity. The blends contain an emulsion of a bituminous binder and an emulsion of a tapered block copolymer formed from a monovinyl aromatic compound and a conjugated diene. Suitable tapered block copolymers include a tapered A-B-A type block copolymer of the A-t-B-t-A configuration, particularly those having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent, and tapered A-B-A type block copolymers of the A-B-t-A configuration having an isolated styrene content of about 20 to about 90 weight percent of the total monovinyl aromatic compound in the tapered block copolymer. Also disclosed is a method of applying the blends to various surfaces.

Abstract: Narrow molecular weight telechelic and/or block copolymers are prepared by anionic polymerization using multifunctional lithium initiator in combination with a C.sub.2-16 lithium alkoxide.

Abstract: Tapered block copolymers of monovinylidene aromatic monomers and conjugated diene monomers having an isolated polymerized monovinylidene atomatic content of from 30 to 75 percent, hydrogenated derivatives thereof and a process for their preparation.

Abstract: A thermoplastic blend useful for the preparation of molded articles comprising a thermoplastic polymer and a tapered triblock elastomer of a monovinylidene aromatic monomer and butadiene having a melt index (condition 200/5.0 ASTM method D1238-82) of 0.5 to 60 and an average molecular weight from 50,000 to 135,000.

Abstract: A method for preparing an asymmetric, semi-permeable membrane containing a uniform microporous structure for gas and liquid separation, including forming a dense separation on one major surface of a microporous support structure. The microporous support structure is initially formed as a solid unitary film, fiber or sheet by the simultaneous extrusion of at least two streams of heat-plastified polymeric materials including at least two differentially soluble polymeric materials. The separation layer can be formed on the support structure prior to or after the soluble polymeric material has been dissolved out of, as by leaching from the solid support structure to form the microporous support for the separation layer. Preparation in this manner greatly reduces the tendency to form undesiralbe pinholes in the membrane.

Abstract: Asymmetric membranes are prepared by treating a major surface of a glassy polymer composition to render the surface resistant to solvent crazing and then contacting the glassy polymer composition with a crazing solvent. The crazing solvent permanently deforms the glassy polymer composition by forming a microporous structure on the untreated surface. The treated surface becomes the dense, discriminating layer of the membrane which achieves desirable permeation selectivity. The methods of treatment are (1) crosslinking, (2) providing an agent which renders the surface resistant to crazing, and (3) providing an agent which reacts with the surface. Additionally, the glassy polymer composition can be crosslinked before or after it is crazed to increase the mechanical strength of the membrane.

Abstract: Semipermeable membranes with improved permeation flux are prepared by contacting a glassy polymer in the form of a hollow fiber or film with a solvent in which the polymer swells at conditions which permit the swelling solvent to diffuse into the glassy polymer and then stretching the swollen polymer in an amount sufficient to cause visible stress whitening.

Abstract: A pressure sensitive adhesive composition is provided. The adhesive comprises an ABA block polymer wherein A represents a copolymer of styrene and alpha-methylstyrene and B represents blocks of diene polymer. The diene polymer can be butadiene, isoprene or a mixture thereof. The composition also contains a tackifying resin.

Abstract: ABA block copolymers containing N,N-disubstituted acrylamides in the A blocks and butadiene polymer in the B block provides thermoplastic elastomer adhesives or compatibilizing agents for polymer blends.

Abstract: An improved method for the polymerization of mixtures of mixed cis and trans-isomers of 1,3-pentadiene in the production of block copolymers. By continuously or incrementally adding a cis-isomer of 1,3-pentadiene polymerization promoter, using a hydrocarbon solvent with no aprotic solvents of a polar nature and not exceeding specified temperature ranges, the cis-isomer of 1,3-pentadiene is polymerized, resulting in a greater 1,3-pentadiene polymerization yield. The polymerization promoter is a vinyl-substituted aromatic monomer, for example styrene.

Abstract: Block copolymers having two or more blocks may be prepared from vinyl-substituted aromatic hydrocarbons and a mixed isomer mixture of 1,3-pentadiene. At least one block is polymerized from the cis and trans-isomer mixture of 1,3-pentadiene. The amount of the mixed isomer mixture of 1,3-pentadiene polymerized may be increased by including in the mixed isomer mixture a cis-isomer polymerization promoter.

Abstract: Membrane compositions useful in filtration and distillation applications are prepared by providing a glassy polymer composition (e.g., polystyrene) optionally having an amount of crosslinking and crazing the polymer composition in the presence of a monomer (e.g., methyl methacrylate) which can graft to said polymer composition. The membrane compositions so prepared comprise a microporous structure wherein the micropores can contain polymeric material. Alternatively, the surface region of the membrane composition and/or the surface region of the micropores has a polymeric material grafted thereto.

Abstract: Block copolymers of the AB(BA).sub.n configuration are employed in the preparation of asphalt blend concentrates. Advantageously asphalt is blended with polymer solution from polymerization reactor and subsequently devolatilized.

Abstract: .alpha.-Methylstyrene-styrene copolymer is blended with an .alpha.-methylstyrene-styrene diene block copolymer or copolymers to provide impact resistant molding material.

Abstract: Block copolymers are prepared having end blocks with random copolymer of styrene and/or alkyl substituted derivatives and alpha-methylstyrene ranges from 1:0.5 to 1:2.5, a central block of a polydiene polymer joins the terminal blocks. The block copolymers contain from 10 to 90 weight percent of polydiene, the remaining portion being of random (alkyl) styrene-alpha-methylstyrene copolymer. The polymers range from medium impact polystyrene type polymer of low polydiene content to thermoplastic elastomers of high polydiene content.

Abstract: Diene-styrene-.alpha.-methylstyrene block polymers are prepared by polymerization in excess .alpha.-methylstyrene with a lithium initiator wherein styrene-.alpha.-methylstyrene block is polymerized at a temperature from about 20.degree. centigrade to about 160.degree. centigrade with the ratio of styrene to .alpha.-methylstyrene being from about 50 to 1 to about 1 to 50.

Abstract: Styrene is polymerized employing a free radical initiator in the presence of a styrene-diene block copolymer of the AB or AB (BA).sub.n configuration to provide a polymer containing from about 15 to 30 weight percent diene units polymerized therein. The polymer contains polydiene domains in the form of rods and spheres having diameters of 50 nanometers or less.