Process for the Preparation of Solid Particulate Vinyl Aromatic Polymer Compositions

摘要

A novel process for preparing vinyl aromatic polymer particles is described. The particles and beads are suitable for being processed into foamed styrenic products of substantially improved insulation values, as well as other useful products.

主权项

1. A process for the preparation of a solid particulate vinyl aromatic polymer composition, wherein the process comprises:
(i) providing an aqueous mixture comprising styrene and/or styrene derivative(s), a suspension stabilizer, at least one initiator and optionally a flame retardant, wherein the styrene and/or styrene derivative(s) content is less than 40 wt % with respect to the total weight of the mixture as provided in (i), (ii) polymerizing styrene and/or styrene derivative(s) of (i) via suspension polymerization to form seeds, (iii) subsequent to (ii) dosing of additional styrene and/or styrene derivative(s) and same or different at least one initiator to the formed aqueous suspension and further polymerizing styrene and/or styrene derivative(s) through seed polymerization to produce an aqueous suspension comprising at least 45 wt % of suspension organic phase with respect to the total weight of the suspension as present at the end of (iii).