A KINETIC-STUDY OF HOMOGENEOUS BULK-POLYMERIZATION OF ETHYL-METHACRYLATE INITIATED BY BENZOYL PEROXIDE AND AN N,N'-DIMETHYLANILINE REDOX PAIR

The homogenous bulk polymerization of ethyl methacrylate (EMA) was stu died using benzoyl peroxide (BPO) and an N,N'-dimethylaniline (DMA) re dox pair with the dilatometric method. The half-order dependence of th e polymerization rate upon both the BPO and DMA concentrations was obt ained. The overall activation energy of the polymerization was found t o be between 32.3-55.3 kJ/mole for different initial molar ratios of t he redox pair. A retaring effect was observed at lower polymerization temperatures for low concentrations of BPO. The formation of reddish c olored polymers at higher DMA concentrations was explained by the adso rption of adduct formed between DMA radicals.