ALTERNATIVE METHODS TO CONTROL CROSSLINKING IN HIGH IMPACT POLYSTYRENE

摘要

High impact polystyrene may be formed with increased swell index and reduced or eliminated discoloration. A process of forming high impact polystyrene may include providing a polymerization system including a polymerization reactor and a devolatilizer. High impact polystyrene may be formed in the polymerization reactor, and sent to the devolatilizer. A polar antioxidant having a hindered phenol structure and an aliphatic amine group, and with a phosphite antioxidant may be added to the polymerization system. In another process, a chemical retarder and a fluorescent whitening agent may be added to the polymerization system. In another process, a chemical retarder that inhibits free radical rubber crosslinking may be added to the polymerization system.

主权项

1. A process comprising:
providing a polymerization system comprising a polymerization reactor upstream of a devolatilizer; forming a high impact polystyrene within the polymerization reactor; sending the high impact polystyrene to the devolatilizer; adding a polar antioxidant to the polymerization system, wherein the polar antioxidant has a hindered phenol structure and an aliphatic amine group, and wherein the polar antioxidant is added to the polymerization system at or upstream of the devolatilizer; and adding a phosphite antioxidant to the polymerization system, wherein the phosphite antioxidant is added to the polymerization system at or upstream of the devolatilizer.