Synthesis Of Poly(styrene-b-n-butyl Acrylate-b-styrene) Triblock Copolymer Latex Via AGET Cationic Emulsion ATRP

This article provided a kind of preparation method producing cationic emulsions of triblock copolymer particles, which should be friendly to environment, wide range of monomers and mild reaction conditions, in order to solve the existing limitations of triblock copolymer synthesis methods and the severities of synthesis conditions, and production could be used directly.In this paper, organic halide with bifunctional group named ethylene bis(2-bro-moisobutyrate) was conducted as initiator, and transition metal complex as halogen atom carrier, strong hydrophobic pyridine derivative as ligand, cationic surfactant as emulsifier and vitamin C as reducing agent were adopted. Poly(styrene-b-n-butyl acrylate-b-styrene) triblock copolymer cationic latex and poly(styrene-b-hexyl acrylate-b-styrene) triblock copolymer cationic latex were synthesized by activator generated by electron transfer atom transfer radical cationic emulsion polymerization with two steps directly.For the sake of simplicity, sequential monomer additions were performed without any removal of unreacted monomer. In terms of poly(styrene-b-n-butyl acrylate-b-styrene) triblock copolymer cationic latex, effects of different types of ligands and different cationic surfactants on this system were discussed in details. The maximal polymerization degree of n-butyl acrylate block was investigated, and a series of poly(styrene-b-n-butyl acrylate-b-styrene) triblock copolymer cationic latex with different n-butyl acrylate block were synthesized by adjusting the different proportions of monomer and initiator. The most suitable polymerization degree of n-butyl acrylate block was studied, and a series of poly(styrene-b-n-butyl acrylate-b-styrene) triblock copolymer cationic latex with different styrene block were synthesized under such circumstance. The molecular weight and molecular weight distribution of the resultant copolymers were characterized by gel permeation chromatography(GPC). Thermal weight loss of triblock copolymers was studied by thermal gravity analysis(TGA). Glass transition temperature of triblock copolymers was investigated by differential scanning calorimeter(DSC). Dynamic light scattering(DLS) was used to characterize particle size and particle size distribution of resulted latexes, and the resultant latexes showed good colloidal stability with average particle size around 100~300 nm in diameter.The maximal polymerization degree of hexyl acrylate block was investigated, and a series of poly(styrene-b-hexyl acrylate-b-styrene) triblock copolymer cationic latex with different hexyl acrylate block were synthesized by adjusting the different proportions of monomer and initiator. The polymerization kinetics of hexyl acrylate was studied, and the particle size of the triblock copolymer latex during the whole process of polymerization was tracked.