Study on depolymerisation of poly(trimethylene terephthalate) in supercritical methanol by GPC-HPLC-IR

The degradation behaviour of poly(trimethylene terephthalate) (PTT) in supercritical methanol was investigated to develop a chemical recycling process for waste plastics. GPC and HPLC combined with FTIR spectrometry were applied to qualitative and quantitative analysis of products. DMT, MHPT, BHPT, MHET, BHET and HEHPT were found to be the main reaction products. The yields of monomer components are strongly consistent with the bond energy differences in the repeat unit. The detailed reaction process was discussed based on the experimental data. Further investigation indicates that the complex characteristic of supercritical fluids and impurities in raw materials can result complication in products. (C) 2004 Elsevier Ltd. All rights reserved.