Oxidative chemical recycling of polyethylene

The oxidative chemical recycling of polyethylene to a series of short chain diacid products, i.e., succinic, glutaric, adipic, and pimelic acids, was presented. These products have great value economically as monomers for the production of nylon or as industrial solvents when converted to diesters. Reaction of various polyethylenes under the described conditions was presented. Regardless of starting material, yields of glutaric, adipic and pimelic acids stayed consistent to within ∼ 0.1 mmole. However, the amount of succinic acid produced was inconsistent between samples. Acids higher than that of pimelic were not detected in the reactions. Results for low density polyethylene (LDPE) showed that shortening reaction time significantly reduces the amount of succinic acid produced with Reaction 4 producing better than 10% less succinic acid than Reaction 1. By increasing the reaction temperature and heating the sample in two steps, LDPE could be converted exclusively to succinic, glutaric, adipic, and pimelic acids. No side products from nitration were observed, showing that the system is truly catalytic in NO used.