Polymer recovery through selective dissolution of co-mingled post-consumer waste plastics

It still remains a challenge to the recycling industry to develop an efficient and economical large-scale plastic waste recycling system, in spite of growing environmental concerns in waste disposal. Selective dissolution and precipitation (SDP) is a mechanical recycling technique that eliminates pre-sorting of mixed waste plastics and recycling polymer of high-grade quality. In this preliminary investigation, recycling of a comingled post-consumer waste plastic mixture of low-density polyethylene (LDPE), polystyrene (PS), high-density polyethylene (HDPE), and polyethylene terephthalate (PETE) using a lab-scale SDP setup was examined. A few experimental runs performed on the representative samples using Xylene/Toluene as solvents and acetone/2-propanol as anti-solvents demonstrated the sorting and recycling efficiency of this technique. FT-IR analysis of the reclaimed products revealed that the structural properties being very similar to virgin materials.