Research on Determination for Food-Related Polystyrene Doped with Recycled Plastic by GPC

Polystyrene (PS) had wide range of applications in food packaging field. Mechanical recycling of PS was simulated by multiple extrusions to assess the behavior of physical degradation. The molecular weight and the molecular weight distribution of PS with different extrusion cycles were investigated by gel permeation chromatography (GPC). Experimental results show that the differential and cumulative distribution curves of PS shift to smaller values with the number of extrusions cycled increasing. The Mn and Mw of PS decrease. However, Polydispersity index (PDI) increases obviously.