Miniemulsion and macroemulsion copolymerization of vinyl acetate with vinyl versatate

Abstract

ABSTRACT:The miniemulsion and macroemulsion polymerization of vinyl acetate with vinyl versatate in batch and semibatch systems was investigated. Vinyl versatate was added either as an emulsion with the vinyl acetate, or as a neat liquid stream. In the batch runs, there is a poor dispersion of vinyl versatate during the nucleation period for the runs in which the vinyl versatate was added neat at the beginning of the polymerization. This led to smaller particles, lower polymerization rate, and different polymer composition evolution when compared with runs in which the vinyl versatate was emulsified with the vinyl acetate. In seeded semibatch runs, residual surfactant in the seed latex, along with the propensity for homogeneous nucleation in vinyl acetate emulsions, resulted in continuing nucleation during the entire semibatch interval. The polymerization rate was primarily affected by monomer feed rate rather than the feeding mode. The effect of monomer feeding mode on copolymer composition was weak when the semibatch feed rate was low, indicating some level of vinyl versatate mass transfer resistance. In all runs, only one glass transition temperature was observed, indicating effective copolymerization.

Miniemulsion Copolymerization of Ethylene and Vinyl Acetate

“…Even for monomers with as low solubility as styrene (water solubility at 60 °C: 0.24 wt.‐%), there is no evidence of transport limitation. However, ethylene has very low water solubility of ≈0.008 wt.‐% at 60 °C and 1 atm,8 which is approximately the same water solubility as vinyl versatate, a monomer known to have very low water solubility 9. The difference is that vinyl versatate is emulsion copolymerized in small amounts to improve the water resistance of VAc‐based coatings, while here we are attempting to include more that 50% (monomer fraction) of ethylene into VAc.…”

Influence of redox initiator component ratios on the emulsion copolymerisation of vinyl acetate and neodecanoic acid vinyl ester

“…Appendix Table A4 † for detailed intensities of the signals). This could be due to the very low water solubility of Versa®10 (2.58 wt% vinyl acetate against 7.5 × 10 −4 wt% Versa®10 at room temperature 50 ), which would increase at higher temperature and therefore facilitate the implementation of the monomer into the final polymer.…”

Continuous Miniemulsion Polymerization

“…Wu et al29 also investigated miniemulsion and macroemulsion copolymerization of VAc and vinyl versatate (VEOVA) in batch and seeded semibatch manners. At room temperature, the water solubility of VAc is 2.58 wt.‐%, and vinyl versatate is 7.5 × 10 −4 wt.‐%.…”