Abstract: Poly(polyethylene glycolcocitric acid) (PEGCA) was synthesized via condensation reaction between citric acid and polyethylene glycol. Its reaction kinetics and rheological behaviors of the product were studied. It showed that the energy of activation was 61.9 kJ/mol and the frequency factor was 1.89×105 kg/mol·min. Measurements showed that the PEGCA samples were Newtonian fluid. The only exception was the sample prepared with the reaction temperature and time of 130 ℃ and 35 h, respectively, measured at 60 ℃, While the reaction time is 35 h,its nonNewtonian index and consistency were 1.3 and 1.3×106 mPa·sn, respectively. The relatively low viscous activation energy (31~40 kJ/mol) of PEGCA is showed that the reaction time had little effect on the viscous activation energy.

Key words: citric acid, polyethylene glycol, biodegradation, reaction kinetic, rheological behavior, viscosity