Biodegradable PVC plasticizer derived from a new CO2-based Poly (carbonate-ester) macrodiol: Molecular design and plasticizing effect

A completely new poly(carbonate-ester) macrodiol (PPCP-mDL), derived from direct copolymerization of carbon dioxide (CO2), propylene oxide (PO), phthalic anhydride (PA) and 1, 4-butanediol (BDO) catalyzed by metal-free triethylborine (TEB)/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) pairs has been developed. The molecular weight of PPCP-mDL produced varying from 1.1-2.3 kg mol-1 can be easily controlled through the regulation of reaction conditions. For the formulation of non-toxic, phthalate-free flexible PVC, novel and biodegradable ecPPCP-mDL with high molecular weight may be obtained through end-capping the PPCP-mDL using benzoyl chloride. The ec-PPCP-mDL/PVC blends display better comprehensive plasticization performance than do comparable blends with commercial DEHP plasticizers. These blends exhibit high thermal stability, mechanical properies, plasticizer migration resistance and transmittance. The interaction between ec-PPCP-mDL and PVC has been characterized using FTIR spectroscopy. A possible mode of plasticization has been suggested. The rich ester groups in the structure of ec-PPCP-mDLs interact well with PVC via hydrogen bonding, resulting in excellent compatiblity with PVC. Overall, the novel ec-PPCP-mDL material, respects an attractive alternative to plasticizers as a green, non-toxic, biodegradable, partially sustainable for the preparation of flexible PVC formulations.