Environmentally-Friendly Acrylates-Based Polymer Latices - Advanced Materials for Agriculture, Food and Environmental Safety - page 152

nature having similar composition as in the monomer feed. Hwa [27] syn-
thesized MMA and methylene dimethacrylate copolymer by suspension
polymerization at 60 C in the presence of a free radical catalyst.

Statistical copolymer i lms that consist of two types of monomers, a
sticky and a glassy monomer, were investigated by Diethert et al. [28].
h ese model systems of pressure-sensitive adhesive i lms were probed
with X-ray rel ectivity and mechanical tack measurements. h e inl uence
of the type of monomers being copolymerized, the monomer ratio, and the
sample age on the near-surface composition as well as the resulting adhe-
sive performance of the i lms were analyzed. h e copolymer contains EHA
as the major component and styrene, maleic acid anhydride, or MMA as
a minor component. h e minimization of surface free energy resulted in
an internal reorganization and the component of the statistical copolymer
with the lower surface tension was enriched at the free surface.
Zhang et al. [29] synthesized an acrylic emulsion of MMA, BA, and
acrylic acid with high hydroxyl content. In their work ammonium persulfate
was used as initiator; sodium lauryl sulfate (SLS) mixed with p-octyl poly-
ethylene glycol phenyl ether (OP) was used as emulsii er. It was concluded
that emulsion with high hydroxyl content is useful in the coating industry.
Moraes et al. [30] investigated MMA, BA, and EHA as alternatives to
EA in the composition of methacrylic acid (MAA)-EA copolymers for
the production of hydrophobically-modii ed alkali-soluble emulsions. h e
EHA gave reasonable results as a replacement comonomer for the synthe-
sis and applications of alkali-soluble emulsion.
Latex properties of poly(urethane acrylate) (Pu-A) and MMA copoly-
mer have been studied by Zhang et al. [31] h ey found that the cast i lm
was signii cantly inl uenced by the amount of 2-hydoxypropyl acrylate,
dimethylpropionic acid and MMA.
Bakhshi et al. [32] used emulsion polymerization for the synthesis
of poly(butyl acrylate-co-glycidyl methacrylate) by selecting dif erent
monomer feed ratio at 75

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C with potassium persulfate (KPS) as initiator.
Solubility, gel content, and copolymer compositions were determined. h e
composition of copolymer was determined by the 1 H-NMR analysis.
H.Y. Erbill [33] copolymerized vinyl acetate and BA monomer by emul-
sion polymerization using the controlled monomer and initiator addition
method. Particle size distribution, viscosity average molecular weights, Tg
and molar composition of the copolymers were determined. Surface ten-
sion components of the copolymer i lms were calculated from contact angle
data of various liquids by using van Oss-Good methodology. A decrease
of average particle size and Tg was found by the increase of BA content.
Surface tension was also af ected by the BA content in the monomer feed.

°