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High pressure semibatch emulsion and miniemulsion copolymerization of vinyl acetate and ethylene
Author(s) -
Narayanan Manu,
Choi Kyu Yong
Publication year - 2021
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.49784
Subject(s) - miniemulsion , copolymer , polymerization , polymer chemistry , emulsion polymerization , emulsion , vinyl acetate , materials science , ethylene , chain transfer , chemistry , chemical engineering , polymer , organic chemistry , radical polymerization , catalysis , engineering
This study presents the experimental study of semibatch emulsion and miniemulsion copolymerization of vinyl acetate (VAc) and ethylene to vinyl acetate‐ethylene (VAE) copolymer at 60°C and 80–300 psig. In the miniemulsion copolymerization, a water‐soluble initiator (K 2 S 2 O 8 ) is used and VAc miniemulsion is prepared in presence of surfactant and cosurfactant using a sonicator or a high‐shear homogenizer. Then, ethylene gas is supplied to the reactor at constant partial pressure. In a miniemulsion process, the mass transfer limitations of VAc from monomer droplets to the aqueous phase, and to micelles or polymer latex particles that are present in conventional macro‐emulsion polymerization can be eliminated and the transfer of ethylene dissolved in the aqueous phase to the miniemulsion droplets is the major ethylene transport process for the polymerization. The experimental data show that the amount of ethylene incorporation into the copolymer is higher in miniemulsion polymerization than in emulsion polymerization. The ethylene pressure has been found to have a strong impact on the ethylene incorporation into the copolymer phase in both emulsion and miniemulsion copolymerizations but the increase is more pronounced in miniemulsion case. The VAE copolymer latex particles prepared by miniemulsion polymerization exhibited higher storage stability than those prepared by macro‐emulsion polymerization.