Copolymerization Kinetics of Polyetyhylenglycol Allylether Type Polycarboxylate Superplasticizer

摘要

The free radical copolymerization kinetics of polyethylenglycol allylether (APEG) with acrylic acid(AA) had been studied in aqueous solution through using ammonium persulfate(APS) and 30% hydrogen peroxide(H_2O_2) as initiators. The structure of polycarboxylate superplasticizer had been characterized by IR and 'H-NMR. The rate of copolymerization was proportional to the molar ratio of monomers (AA:APEG) to the power of 0.4405, and to the amount of initiator (1.5%APS-2%H_2O_2, mass ratio to monomers) to the power of 0.7819, respectively. The overall observed activation energy of copolymerization was 45.048 kJ/mol. The kinetic relationship of copolymerization reaction of APEG with AA had been established as follow: Rp∝[APEG/AA]~(0.4405)[APS-30% H_2O_2]~(0.7819)e~((-5418)/T). The temperature and initiator were main influencing factors on polymerization reaction.