Homopolymerization of 1,8Dioxan-2-one to High Molecular Weight Poly(Trimethylene Carbonate)

Abstract

Abstract 1,3-Dioxan-2-one was synthesized from 1,3-propanediol and di-ethyl carbonate by using either sodium ethoxide or stannous 2-ethythexa-noate as the transesterification catalyst. The latter method gave the monomer in a yield of over 50%. 1,3-Dioxan-2-one was polymerized by ring-opening polymerization to poly(trimethylene carbonate) by using cationic and anionic initiators. The conditions were varied with different solvents and without solvent, and with different reaction temperatures, different reaction times, and different atmospheres. Polymerization in solution gave mixtures of oligomers and polymers with molecular weights less than 50,000. Bulk polymerization, especially at higher temperatures, and preferably using BF3O(C2H5), as initiator, gave poly(tri-methylene carbonate) with a molecular weight in excess of 100,000. Higher reaction temperatures gave a higher molecular weight and a faster polymerization rate, but excessive heating caused thermal degradation of poly(trimethylene carbonate). The...