Block Copolymer Composite Synthesis in a Mechanistic Approach

Abstract

Carbon nanotubes-block copolymer composites were synthesized via reversible addition–fragmentation chain transfer living emulsion mechanism, based on zero–one and pseudo-bulk kinetics. In conjunction with multiwalled carbon nanotubes, ab initio reversible addition–fragmentation chain transfer homopolymerization of styrene and butyl acrylate, respectively, was carried out using xanthate-based reversible addition–fragmentation chain transfer agent through ultrasonified macroemulsion and miniemulsion. Then, the second and third monomer were applied at stage II and III, respectively, to produce multiwalled carbon nanotube diblock and triblock copolymer composites such as multiwalled carbon nanotube-b-poly(styrene)-co-polybutyl acrylate-co-polymethyl acrylate and multiwalled carbon nanotube-b-polybutyl acrylate-co-polymethyl acrylate-co-poly(styrene). As multiwalled carbon nanotube-homopolymer proceeds to diblock and triblock, thermal resistance of multiwalled carbon nanotube block composite products is enhanced. A mechanistic approach of reversible addition–fragmentation chain transfer living macroemulsion and miniemulsion polymerizations, with the purified multiwalled carbon nanotubes enables us to control the composite properties such as thermal degradation, mechanical strength, and glass transition temperature of multiwalled carbon nanotube-block copolymer composites, in conjunction with reaction conditions, monomer type, blocking sequence, particle size, and molecular weight.