TY - JOUR
T1 - Emulsion polymerization of styrene using an alkali-soluble random copolymer as polymeric emulsifier
AU - Lee, D. Y.
AU - Kim, J. H.
PY - 1998/11/30
Y1 - 1998/11/30
N2 - An alkali-soluble random copolymer (ASR), poly(styrene/α-methylstyrene/ acrylic acid), was used as a polymeric emulsifier in the emulsion polymerization of styrene. The calorimetric technique was applied to study the kinetics of emulsion polymerization of styrene using ASR and a conventional ionic emulsifier, sodium dodecyl benzenesulfonate (SDBS). ASR could form aggregates like micelles, and the solubilization ability of the aggregates was dependent on the neutralization degree of ASR. The rate of polymerization in the ASR system was lower than that in the SDBS system. This result can be explained by the creation of a hairy ASR layer around the particle surface, which decreases the diffusion rate of free radicals through this region. Although a decrease in particle size was observed, the rate of polymerization decreased with increasing ASR concentration. The higher the concentration of ASR is, the thicker and denser ASR layer may be, and the more difficult it would therefore be for radicals to reach the particle through this layer of ASR. The rate of polymerization decreased with increasing the neutralization degree of ASR. The aggregates with high neutralization of ASR are less efficient in solubilizing the monomer and capturing initiator radicals than that of the lower neutralization degree, which leads to decrease in rate of polymerization.
AB - An alkali-soluble random copolymer (ASR), poly(styrene/α-methylstyrene/ acrylic acid), was used as a polymeric emulsifier in the emulsion polymerization of styrene. The calorimetric technique was applied to study the kinetics of emulsion polymerization of styrene using ASR and a conventional ionic emulsifier, sodium dodecyl benzenesulfonate (SDBS). ASR could form aggregates like micelles, and the solubilization ability of the aggregates was dependent on the neutralization degree of ASR. The rate of polymerization in the ASR system was lower than that in the SDBS system. This result can be explained by the creation of a hairy ASR layer around the particle surface, which decreases the diffusion rate of free radicals through this region. Although a decrease in particle size was observed, the rate of polymerization decreased with increasing ASR concentration. The higher the concentration of ASR is, the thicker and denser ASR layer may be, and the more difficult it would therefore be for radicals to reach the particle through this layer of ASR. The rate of polymerization decreased with increasing the neutralization degree of ASR. The aggregates with high neutralization of ASR are less efficient in solubilizing the monomer and capturing initiator radicals than that of the lower neutralization degree, which leads to decrease in rate of polymerization.
KW - Aggregate
KW - Alkali-soluble random copolymer
KW - Hairy ASR layer
KW - Polymeric emulsifier
KW - Rate of polymerization
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U2 - 10.1002/(SICI)1099-0518(19981130)36:16<2865::AID-POLA4>3.0.CO;2-7
DO - 10.1002/(SICI)1099-0518(19981130)36:16<2865::AID-POLA4>3.0.CO;2-7
M3 - Article
AN - SCOPUS:0032208983
SN - 0887-624X
VL - 36
SP - 2865
EP - 2872
JO - Journal of Polymer Science, Part A: Polymer Chemistry
JF - Journal of Polymer Science, Part A: Polymer Chemistry
IS - 16
ER -