STUDY ON RING-OPENING POLYMERIZATION OF 2 ,2-DIMETHYLTRIMETHYLENECARBONATE AND PHYSICOCHEMICAL AND MECHANICAL-PROPERTIES

2,2-Dimethyltrimethylenecarbonate (DMTMC) was polymerized in bulk cond ition with stannous octoate as a catalyst. The activation energies of DMTMC and D,L-lactide (DLLA) for polymerization were about 100 and 90 kJ/mol, respectively. Several kinds of physicochemical properties were evaluated. T-m and T-g of poly(DMTMC) were 120 and 33 degrees C, resp ectively, which were lower than those of poly(L-lactide) (PLLA) and po ly(glycolide) (PGA). T-m was not observed for poly(DMTMC-co-LLA). The tensile strength and the Young's modulus of PDMTMC were smaller than t hose of amorphous poly(D,L-lactide) (PDLLA), in spite of high crystall inity. The mechanical properties and degree of in vitro hydrolization of poly(DMTMC-co-LLA) varied with its composition, though hydrolytic d egradation of PDMTMC itself was extremely depressed compared with PLLA .