Expanded polystyrene made using D-limonene as a plasticizer

摘要

Disclosed is a process for production of expanded polystyrene using D-limonene as a plasticizer, which allows reducing the amount of pentane in the process, yet allows generating beads with similar cell size as if greater quantities of pentane had been used. Pentane is an organic solvent with toxicity associated with organic solvents.

主权项

1. A process of forming expanded polystyrene beads having internal cells of a size typically generated by including a larger amount of pentane in the formulation, comprising:
heating a mixture of styrene, demineralized water, brominated flame retardant chemicals, a peroxide first polymerization initiator, paraffin, tricalcium phosphate (TCP), a surfactant, an extender and D-limonene to a first polymerization temperature; adding 3-8% by weight pentane and a second polymerization initiator to the mixture and heating to a second polymerization temperature to form EPS beads having cells as large as if about 25% more pentane was used than the amount of pentane which actually was used.