Mechanical performance of styrene-2-ethylhexyl acrylate polymers synthesized by semicontinuous emulsion polymerization varying feed composition

A semicontinuous emulsion process varying comonomer feed composition in the course of the reaction is used here to produce copolymer chains of different composition as conversion proceeds. Polymeric material global composition and evidence of branching are determined by 1H-NMR. The ? determined by GPC is beyond the range where the mechanical properties depend on molecular weight. Static and dynamic mechanical properties of variable composition copolymers exhibit highly improved copolymer type behavior for all tested compositions (styrene content between 30 and 85 wt%), showing high superiority of the mechanical performance in comparison with random copolymers and two-stage polymers of equivalent composition, synthesized also by emulsion polymerization. Copyright Taylor & Francis Group, LLC