Mechanical Properties of Polystyrene Recycled Using d-Limonene

Abstract

The mechanical properties of polystyrene recycled using d-limonene were investigated. d-Limonene dissolves only polystyrene; the degree of extraction of other plastic is less than 2 wt%. We found that polystyrene recycled 5 times containing at least 0.3×10^-2 mol/100 g of residual limonene content retains its original mechanical properties because there is only a 12% decrease in the molecular weight of the polystyrene, whereas polystyrene recycled once using the conventional method of thermal shrinking has a 35% decrease in molecular weight compared with new polystyrene. The deviation of the molecular weight change of about 2.7 tons of polystyrene recycled using d-limonene is within 10% and the mechanical properties in this range of molecular weights are the same except impact strength and melt flow rate. The 20 wt% blend of the polystyrene recycled to TV cabinet material has the same mechanical properties, flammability and melt-flow rate if there is a small adjustment in the material composition.