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/FeCl 3 /2,2′ bipyridine as the ATRP catalyst system and ethyl-2-bromo-isobutyrate as co-initiator in N, N′-dimethyl formamide at 100 °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 °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 .