Study on soapless emulsion copolymerization methyl methacrylate and n‐butyl acrylate

Abstract

The soapless emulsion copolymerization of methyl methacrylate (MMA) and n‐butyl acrylate (n‐BuA) at four levels of monomer feed composition (f10) was studied. Conversion (X), average particle diameter (Dp), molecular weight distribution (MWD), surface charge density, and glass transition temperature (Tg) of the copolymer as a function of reaction time (t) were measured. The copolymers obtained even at low conversion, except for the run of (f10) = 90 wt. percent MMA, exhibit two Tgs in their DSC thermograms. Phase separation is found to occur in the latex particles during polymerization. The heterogeneous distribution of monomers in particles, in which a relatively rich MMA region exists in the shell and a relatively rich n‐BuA region exists in the core of the particles, is assumed to arise from phase separation. The average copolymer composition and the fraction of the two domains are estimated. The polymerizatrion course and particle size growth follow the linear X vs. t2 and Dp3/2 vs. t relationships, respectively. Although the coagulation of particles happens after around 30 percent conversion, the polymerization behaviors, except for increasing rates, are not affected.

Modeling and experimental studies of emulsion copolymerization systems. III. Acrylics

“…Methyl methacrylate/butyl acrylate (MMA/BA) emulsion copolymerization has been studied by several researchers focusing on kinetic and particle structure aspects,5–12 soapless emulsion polymerization,13, 14 and semicontinuous processes 15–17. Emelie et al5, 6 studied the influence of emulsifier and initiator concentration and monomer to water ratio on the polymerization rate.…”

“…Barton et al10 studied the kinetics of polymerization of MMA over seed particles of poly(butyl acrylate). A number of papers discuss core–shell emulsion copolymerization of BA/MMA with a core rich in BA and a shell rich in MMA 11–14. A practical application of this polymer is the toughening of poly(methyl methacrylate) 12.…”

“…Presumably, the production of emulsifier‐free core–shell BA/MMA particles could be used to reinforce clear poly(methyl methacrylate) without affecting its optical properties. Working with a soapless system, Pan et al13 studied the effect of monomer composition on the final properties of the copolymer. They found evidence of phase separation in the particles ending up with a copolymer containing a BA‐rich phase in the core and an MMA‐rich phase in the shell.…”

Kinetics of the seeded semicontinuous emulsion copolymerization of methyl methacrylate and butyl acrylate

“…Some amount of MMA-rich polymer, presumably produced in the aqueous phase, was detected. Pan et al 7 studied the soapless batch emulsion copolymerization of MMA and BuA. A phase separation with a relatively MMA-rich region in the shell and a BuA-rich region in the core as well as a coagulation of particles after a 30% conversion was reported.…”

Preparation of methacrylic acid‐grafted chitin using cerium (IV) ion and its application in adsorbing paraquat

“…The samples were heated from 30°C at a rate of 10°C/min to 260°C to prevent decomposition of amine at around 295°C 23. Glass transition temperature ( T g ) was taken as the intersection of the extrapolated baseline with the extrapolation of the curve from the point of inflection 24…”