Effects of Reaction Parameters on Particle Size, Molecular Weight, and Kinetics for Dispersion Polymerization of n-Butyl Acrylate

Abstract

Poly(acrylic acid) (PAA) prepared in the presence of n-dodecyl mercaptan (DDM) was used as a steric stabilizer for dispersion polymerization of n-butyl acrylate (BA). The effects of polymerization parameters such as alcohol/water ratios, concentration and molecular weight of PAA stabilizer, concentration and species of initiator, concentration of monomer, and polymerization temperature on number-average particle size and size distribution, weight-average molecular weight, molecular weight distribution, and polymerization rate were investigated. The effects of medium ratio, stabilizer and monomer concentration, and polymerization temperature were similar to those obtained in the conventional dispersion polymerization. However, the effect of molecular weight of PAA stabilizer showed significantly different trends than the existing results. As the molecular weight of PAA decreased, the molecular weight of poly(butyl acrylate) (PBA) and rate of polymerization increased, while the particle size of PBA decreased. This is due to the formation of PAA-block-PBA copolymers, which played a crucial role in particle stabilization.