Abstract: We disclose a monovinylarene/conjugated diene block copolymer, comprising: (i) a random (conjugated dienex/monovinylareney)m block, wherein x is about 2.5 wt % to about 10 wt %, y is from about 90 wt % to about 97.5 wt %, and x+y is about 97.5 wt % to 100 wt %; and (ii) a (conjugated diene)n block; wherein n is from about 20 wt % to about 30 wt %, m is from about 70 wt % to about 80 wt %, and m+n is from about 90 wt % to 100 wt %. We also disclose a method of forming the block copolymer and a method for fabricating an article from the block copolymer. The block copolymer typically exhibits a Tg at least about 10° C. less than the Tg of a reference polymer differing only in that x is about 0 wt % and y is about 100 wt %.

Abstract: Embodiments include articles without plasticizers, having improved clarity, kink resistance, flexibility, melt fracture and die lines. Manufacturing may be conducted with materials comprising polymodal tapered polymers prepared from copolymerizing at least one monovinyl aromatic monomer and at least one conjugated diene monomer followed by coupling with at least one coupling agent.

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

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 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 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.

Abstract: A process for recovering a rubbery polymer from a rubber-in-solvent solution by steam-stripping the solution to produce rubber crumb in aqueous phase using a low molecular weight lactone copolymer as stripping aid.

Abstract: A monovinyl arene, such as styrene, is polymerized with a monofunctional lithium initiator, followed by addition of a conjugated diene, such as butadiene, with additional monofunctional lithium initiator. The resultant block copolymers are coupled to give linear coupled block copolymers or radial coupled block copolymers with a random distribution of homopolymer and copolymer branches. The polymers exhibit increased tack and improved creep resistance in adhesive compositions. The amount of initiator added as the second increment with the second monomer must be greater than the amount added as the first increment with the first monomer.

Abstract: Rubbery coupled conjugated diene/monovinyl-substituted aromatic hydrocarbon teleblock copolymers are prepared by incremental addition of both monovinyl-substituted aromatic hydrocarbon and initiator. The resulting copolymers can be used to produce improved pressure-sensitive adhesives.