A KINETIC STUDY OF THE POLYMERIZATION OF METHYL METHACRYLATE UNDER SUPERCRITICAL FLUID CO_2

摘要

The kinetics of the in situ polymerization of methyl methacrylate (MMA) in the presence of benzoyl peroxide (BPO) initiator under supercritical fluid CO_2 (sCO_2) was studied by high pressure DSC. The influences of the reaction medium, initiator content, and reaction temperature on the polymerization rate were studied. The results indicated that the formation of PMMA follows a first order reaction mechanism. The polymerization rate in the presence and absence of sCO_2 were found to be similar but the exothermic profiles were different, with the polymerization under sCO_2 having a lower profile. Increasing the amount of BPO initiator accelerated the rate of PMMA formation and reduced the induction time. The molecular weight of PMMA produced under sCO_2 was 34% Higher than that obtained in air.