Environmentally-Friendly Acrylates-Based Polymer Latices - Advanced Materials for Agriculture, Food and Environmental Safety - page 159

independent on initiator concentration. Naghash et al. [89] synthesized
vinyl acetate-acrylic emulsion copolymer in the presence of APS as initia-
tor. h ey found that the polymerization rate increases with increasing its
concentration.

6.2.1.3 Monomer(s)

h e emulsion polymerization of MMA and BA in the presence of a small
amount of sodium methacrylate with KPS initiator at 70 C was investi-

gated by Zhang et al. [90]. h ey found the ef ect of BA concentration on
the polymer properties. Increasing the BA in the feed caused the decrease
of particle diameter, surface tension, and viscosity of the latexes and an
increase in particle number, polymerization rate, surface charge density
and average molecular weight of polymers. h e ef ect of the monomer ratio
on the microstructure of BA/MMA emulsion copolymer was investigated
by Gonzalez et al. [91]. h ey observed that the addition of MMA led to a
decrease in conversion rate and gel content.
Va i l et al. [92] synthesized random MMA/BMA copolymers in the pres-
ence of a chain transfer agent. h e reactivity ratios for the monomer pair
and Tg of the polymers were determined. Laureau et al. [93] studied the
ef ect of monomer composition of EHA/MMA (constant positive and neg-
ative gradient) latex particles and found that the homogeneity and hetero-
geneity of copolymer compositions af ected the adhesive strength (tack,
peel and shear).
Tigli and Evren [94] synthesized acrylic resins by emulsion polymer-
ization using MA, EA, and BA monomers. h e i lm structures of homo-
and copolymers were investigated and three of them [P(MMA/BA) 1:1,
P(MMA/EA) 1:1.5, P(MMA/MA) 1:3] were indicated as appropriate bind-
ers for paint production. h e i lms were characterized by their mechanical
properties like hardness, l exibility, adhesion, gloss, and UV resistance.
Yu a n et al. [95] prepared the MMA-BA-MAA copolymer emulsions
as seed latexes and the seeded emulsion polymerization of MMA-MAA-
DVB was used to prepare carboxylated core particles. h e hydrophobic
shell was then synthesized onto the core using styrene, acrylonitrile, and
DVB as comonomers. h e hollow latex particles were obtained by alkali-
zation treatment of the core-shell latex particles. h e ef ects of the feeding
rate of monomer mixture, contents of emulsii er, sodium dodecylbenzene
sulfonate (SDBS) and crosslinking agent DVB, and ratio of the mono-
mers during the core stage and shell stage on the morphology and volume
expansion of the latex particles were investigated. h e results indicated
the formation of monodispersed hollow latex particles of large size when

°