Polyethylene terephthalate) Recycling with Organic Phosphates-I. Increase in Molecular Weight

Recycling of poly(ethylene terephthalate) by processing flakes obtained from post-consumer PET bottles was investigated. Flakes were additivated with organic phosphites during the processing in an internal mixer and the torque and temperature of the melt were monitored in each run. The molecular weight and polydispersity of the recycled PET were measured by viscometry and SEC. Some of the phosphites acted as chain extenders increasing the polymer M w . Best chain extension results were obtained with triarylphosphites, while dialkyl and trialkylphosphites promoted PET degradation. The study showed that triphenylphosphite was the best chain extender used in this work.