Atom transfer graft copolymerization of 2-ethyl hexylacrylate from labile chlorines of poly(vinyl chloride) in an aqueous suspension

Copper-mediated atom transfer radical polymerization (ATRP) is presented as a versatile tool for the graft copolymerization of 2-ethyl hexylacrylate with poly(vinyl chloride) (PVC) in an aqueous suspension. The appreciable solubility of PVC in 2-ethyl hexylacrylate (30%) at temperatures around 130°C makes grafting of the monomer possible from labile chlorines of PVC in aqueous suspensions without the use of additional solvent. The first-order kinetics (rate constant k = 4.2 × 10^-6 s^-1) of the mass percentage increase reveals a typical ATRP fashion of the graft copolymerization at low conversions. The use of a completely organosoluble copper(I) complex of hexylated triethylene tetramine, in combination with α-methylcellulose as a stabilizer, makes the graft copolymerization possible in a dispersed organic phase. Nearly spherical, green particles can be obtained with moderate stirring rates (1000 rpm) in high graft yields. Although the kinetics of the reaction deviates from the first order at high conversions, reasonable graft yields (146%) can be attained within a reaction period of 24 h. In this study, the reaction conditions of the grafting have been studied, and graft products have been confirmed by common techniques such as ¹H NMR, gel permeation chromatography, and differential scanning calorimetry.