Evaluation of the emulsion copolymerization of vinyl pivalate and methacrylated methyl oleate

In this study, we synthesized a new class of copolymeric lattices based on vinyl pivalate (VPi) and modified oleic acid (OA) through a batch emulsion polymerization process. The effects of the chemically modified OA [methacrylated methyl oleate (MAMO)] on the thermal stability, glass-transition temperature (T-g), average molar masses [mass-average molar mass (M-w) and number-average molar mass (M-n)], and molar mass dispersity ((D) over bar) of the copolymers were evaluated. The experimental results indicate that via the introduction of MAMO into the polymer chains resulted in significant reductions in T-g, M-w, M-n, and (D) over bar; this demonstrated a decrease of T-g at approximately 40 degrees C when the MAMO molar fraction equaled 9% compared to the value observed for the pure poly(vinyl pivalate) (PVPi), which was equal to 80.5 degrees C. MAMO incorporation led to a significant decrease in the M-w value observed in the interval, with a differential from approximately 1.6 x 10(3) to 289.6 kg/mol, and (D) over bar values between 2.17 to 1.55, which was when the MAMO molar fraction present in the VPi-containing copolymers varied from zero (pure PVPi) to approximately 9 mol %. We also observed that the thermal stability of the copolymers decreased slightly when the MAMO concentration increased in the reaction medium. Despite this minor drawback, polymer lattices with a high colloidal stability were formed at a high rate of polymerization, and the elevated conversion was within the interval 90-100%. (C) 2016 Wiley Periodicals, Inc.