Abstract: A method including operating a high impact polystyrene (HIPS) reaction system having a devolatilizer downstream of a polymerization reactor, and from which a HIPS product is obtained, and injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being one or more aromatic antioxidants. A HIPS product produced by operating a HIPS reaction system to produce a HIPS product, with the HIPS reaction system including a devolatilizer downstream of a polymerization reactor, and including injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being comprising one or more aromatic antioxidants. The antioxidant may comprise at least one thiol group, at least one cresol group, or both. A system for producing the HIPS product is also provided.

Abstract: A method including operating a high impact polystyrene (HIPS) reaction system having a devolatilizer downstream of a polymerization reactor, and from which a HIPS product is obtained, and injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being one or more aromatic antioxidants. A HIPS product produced by operating a HIPS reaction system to produce a HIPS product, with the HIPS reaction system including a devolatilizer downstream of a polymerization reactor, and including injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being comprising one or more aromatic antioxidants. The antioxidant may comprise at least one thiol group, at least one cresol group, or both. A system for producing the HIPS product is also provided.

Abstract: Disclosed are novel non-linear vinyl polymers comprised of a multifunctional peroxide, and a cross-linking agent and/or a chain transfer agent, and methods of making such polymers having: at least 0.03 branches/1000 backbone carbons; linear portions with a molecular weight (Mw) of 350,000 or less; 0.2 to 3.0 branches/molecule; or, a Mz/Mw of from 1.7 to 5.7. Methods of quantifying branching are disclosed using a linear reference having 0.0 to 0.06 branches/1000 backbone carbons along with SEC techniques and measurements of molecular weight, molecular size, and concentration. Also discovered is a vinyl polymer resin comprised of from 0.1 to 50 weight percent of non-linear polymers having at least 0.06 branches/1000 backbone carbons, where branching is measured using a heat polymerized polystyrene having from 0.0 to 0.06 branches/1000 backbone carbons as a linear reference.

Abstract: Disclosed are novel non-linear vinyl polymers comprised of a multifunctional peroxide, and a cross-linking agent and/or a chain transfer agent, and methods of making such polymers having: at least 0.03 branches/1000 backbone carbons; linear portions with a molecular weight (Mw) of 350,000 or less; 0.2 to 3.0 branches/molecule; or, a Mz/Mw of from 1.7 to 5.7. Methods of quantifying branching are disclosed using a linear reference having 0.0 to 0.06 branches/1000 backbone carbons along with SEC techniques and measurements of molecular weight, molecular size, and concentration. Also discovered is a vinyl polymer resin comprised of from 0.1 to 50 weight percent of non-linear polymers having at least 0.06 branches/1000 backbone carbons, where branching is measured using a heat polymerized polystyrene having from 0.0 to 0.06 branches/1000 backbone carbons as a linear reference.