Ethylene–vinyl acetate semi‐batch emulsion copolymerization: Use of factorial experiments for improved process understanding

Abstract

A good working knowledge of the mechanism and an appreciation of the effects the process variables have on the properties of interest are required for optimization and control of polymerization processes. Despite the importance of ethylene‐vinyl acetate emulsion copolymers, limited kinetic information is available. Results from a series of factorial experiments are presented here which examine the emulsion polymerization of ethylene with vinyl acetate. Copolymers of up to 32 wt % ethylene have been produced at an ethylene pressure of 500 psig and a temperature of 20°C. The effects of the process variables on the rate of polymerization, copolymer composition, particle size and number, molecular weight averages, and gel content are discussed. The kinetic results obtained suggest process improvements for the production of homogeneous copolymer. Mechanistically, the locus of polymerization has been verified as the polymer particles and little water phase polymerization was observed. © 1993 John Wiley & Sons, Inc.

Miniemulsion Copolymerization of Ethylene and Vinyl Acetate

“…The emulsion copolymerization of EVA has been widely studied 5. Penlidis and coworkers 21–24 have published a model for the emulsion copolymerization of ethylene and VAc. However, there are no reports of free radical miniemulsion polymerization of EVA.…”

Reaction engineering of the emulsion homopolymerization of vinylidene fluoride: Progress and challenges

“…While there are undoubtedly reasons to use the horizontal configuration, they are not immediately clear. It is widely accepted in chemical reaction engineering literature that a high aspect ratio is desirable to enhance gas/liquid contacting . It seems obvious that if the gas phase can be entrained (or fed) to the bottom of the reactor, then it will take a reasonably long time to rise back to the vapour space at the top of the reactor, giving the system more time to absorb the species in question.…”

Vinyl Acetate Polymers

“…Vinyl acetate copolymerizes easily with a few monomers, eg, ethylene, vinyl chloride, and vinyl neodecanoate, which have reactivity ratios close to its own (see Table 4). The kinetics and the effect of process parameters on the copolymerization of vinyl acetate with ethylene have been studied (122,123). With some monomers, eg, maleic anhydride, it tends to form alternating copolymers.…”