Kinetics of poly(propylene fumarate)synthesis by step polymerization of diethyl fumarate and propylene glycol using zinc chloride as a catalyst

Diethyl fumarate and propylene glycol were reacted in the presence of a zinc chloride catalyst to synthesize poly(propylene fumarate)(PPF)over a period of 12 hours. The kinetics of the transesteri. cation polymerization at 130±C, 150±C, and 200 ±C were determined by gel permeation chromatography (GPC)analysis. The initial rate of polymerization at each temperature was quanti. ed by calculating the rate of change of the number average molecular weight (Mn). At 200 ±C, gelation of the PPF occurred after 4 h. GPC analysis of the reaction showed that PPF synthesized at 150±C had a higher . nalMn of 4600 (§190)and a higher weight average molecular weight of 10 500 (§760)than at 130 ±C (n D 3). The chemical structure of the PPF was veri. ed by NMR and FT-IR analysis. This study demonstrated that the maximum Mn of PPF by a transesteri. cation reaction is limited due to gelation of PPF at high temperature.