Poly(ethylene-co-BMA) via dual concurrent ATRP-RAFT and its thermokinetic study

Well-defined copolymers of ethylene and butyl methacrylate (BMA) (poly(ethylene-co-BMA)) with narrow molecular weight distribution were synthesized via dual concurrent atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization using 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid as an alkyl pseudo-halide initiator, ascorbic acid/FeCl3/2,2' bipyridine as the ATRP catalyst system and ethyl-2-bromo-isobutyrate as co-initiator in N, N'-dimethyl formamide at 100 A degrees C. From size exclusion chromatography result, controlled molecular weight with narrow molecular weight distributions of poly(ethylene-co-BMA) was obtained in every case. The experimental results indicated that dual concurrent ATRP-RAFT polymerization is more successful over free radical or RAFT polymerization in terms of controlling molecular weight and polydispersity. X-ray diffraction analysis demonstrated the amorphous behaviour of poly(ethylene-co-BMA) while thermogravimetric analysis reveals that the main decomposition of poly(ethylene-co-BMA) occurs in the range 300-420 A degrees C. The multivariate nonlinear regression analysis was performed to establish the mechanism and kinetic model and found that n-dimensional Avrami-Erofeev (An) mechanism was responsible for the decomposition of the synthesized poly(ethylene-co-BMA). The apparent activation energy (E-a) of decomposition of the synthesized copolymer was found to be 211.88 kJ mol(-1).