Abstract: This invention relates to polymer blends, which comprise at least one tapered conjugated diene-monovinylarene block copolymer and at least one styrenic polymer. The polymer blends possess good optical and mechanical properties.

Abstract: This invention relates to polymer blends, which comprise at least one tapered conjugated diene-monovinylarene block copolymer and at least one styrenic polymer. The polymer blends possess good optical and mechanical properties.

Abstract: This invention relates to polymer blends, which comprise at least one tapered conjugated diene-monovinylarene block copolymer and at least one styrenic polymer. The polymer blends possess good optical and mechanical properties.

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 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 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: A process to produce a monovinylaromatic/monoolefin polymer is provided. Said monovinylaromatic/monoolefin polymer is provided.

Abstract: A process to produce a monovinylaromatic polymer is provided. Said monovinylaromatic polymer is provided.

Abstract: This invention provides a process to produce coupled block copolymers and said coupled block copolymers.

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 system and process for purifying a 1,3-butadiene feedstock containing 1,3-butadiene and various impurities by first introducing the 1,3-butadiene feedstock stream to a separation column to produce an intermediate product stream containing 1,3-butadiene and residual impurities and then introducing the produced intermediate product stream through a condenser to a suitable dryer for removing residual impurities from the intermediate product stream and thereby forming a purified 1,3-butadiene stream. The separation column separates an overhead stream, containing 1,3-butadiene and impurities such as propadiene, water and oxygen, and a bottoms stream, containing impurities such as polymerization inhibitor, ethyl acetylene, 1,3-butadiene dimer, pentane and 1,2-butadiene, from the intermediate product stream which leaves the separation column in the form of a vapor side draw stream.

Abstract: This invention provides a process to produce a composition that comprises diluent and copolymer and also provides the composition. The process of this invention comprises: (a) producing a composition that comprises diluent and copolymer; and (b) removing a portion of said diluent from said composition. This produces a composition that has a lower amount of diluent and a lower amount of imperfections.

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 resinous polymodal monovinylarene-conjugated diene block copolymers and polymers produced thereby are provided. The method comprises sequentially contacting under polymerization conditions:(a) a monovinylarene monomer and initiator;(b) initiator and a monovinylarene monomer;(c) a sequence of at least two charges selected from the group consisting of (i) initiator and a monovtnylarene monomer, (ii) a mixture of monovtnylarene monomer and conjugated diene monomor, (iii) a conjugated diene monomer, (iv) a monovinylarene monomer;(d) a coupling agent;wherein the sequence of at least two charges in step (c) can be made in any order. In a preferred embodiment, at least three Initiator charges are provided. In another preferred embodiment, at least three monovinylarene charges precede the first charge containing conjugated diene. In another preferred embodiment, at least four monovinylarene charges precede the first charge containing conjugated diene.

Abstract: A method for preparing blends of a copolymer in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomer in the presence of a randomizer; (2) an initiator and monovinylaromatic monomer; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjuated diene monomers; (5) conjugated diene monomer; and (6) a coupling agent; and the polymodal tapered block copolymers prepared thereby. The copolymers are particularly useful neat or in blends for applications such as packaging and food or drink containers which require transparency and good environmental stress crack resistance.

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 block copolymers from which can be made transparent blue articles comprising sequentially charging under polymerization conditions at least one monovinylaromatic monomer and at least one conjugated diene monomer, wherein at least the first monomer charge is a monovinylaromatic monomer charge polymerized in the presence of an initiator; wherein at least one other charge polymerized in the presence of an initiator is a monomer selected from the group of conjugated diene monomers and mixtures of monovinylaromatic and conjugated diene monomers; wherein the final monomer charge is a conjugated diene charge; and thereafter charging the reaction mixture with at least one coupling agent. The invention copolymers are particularly useful for applications such as packaging, display devices, toys and decorative items in which transparent blue appearance is desired without significant compromise of other physical and mechanical properties.

Abstract: A method for preparing resinous polymodal monovinylarene-conjugated diene block copolymers and polymers produced thereby are provided. The method comprises sequentially contacting under polymerization conditions:(a) a monovinylarene monomer and initiator;(b) initiator and a monovinylarene monomer;(c) a sequence of at least two charges selected from the group consisting of (i) initiator and a monovinylarene monomer, (ii) a mixture of monovinylarene monomer and conjugated diene monomer, (iii) a conjugated diene monomer, (iv) a monovinylarene monomer;(d) s coupling agent;wherein the sequence of at least two charges in step (c) can be made in any order. In a preferred embodiment, at least three initiator charges are provided. In another preferred embodiment, at east three monovinylarene charges precede the first charge containing conjugated diene. In another preferred embodiment, at least four monovinylarene charges precede the first charge containing conjugated diene.

Abstract: A process for stabilizing polymers is provided comprising:(1) contacting at least one hindered phenolic compound and an organic phosphite to form a stabilizing mixture,wherein said contacting is at a temperature sufficient to at least partially dissolve said hindered phenolic compound,wherein said stabilizing mixture is essentially free of organic solvent; and(2) contacting said stabilizing mixture and a polymeric composition comprising a monovinylarene/conjugated diene copolymer;wherein said organic phosphite and said at least one hindered phenolic compound are present in step (2) in an effective amount sufficient to stabilize said polymeric composition. In accordance with another aspect of this invention a method for preparing a stabilizing mixture essentially free of organic solvent is provided.