| Summary: | 碩士 === 國立成功大學 === 化學工程研究所 === 81 === In this article, soap-free emulsion polymerization is applied
make latex particles with heterogeneous structures. Two major
subjects are discussed. For the first part,two hydrophobic
monomers BA、MMA and two hydrophilic monomers MAA、MAM
copolymerize by soap-free emulsion polymerization. We study the
growth、structure and stability of the latex particles. These
particles are analyzed by DSC thremograms and TEM photographs.
Avreage particle sizes are measured by light scattering. They
are core-shell type particles with hydrophobic core and
hydrophilic shell. MAA copolymerizing with BA、MMA can increase
phase separation and raise the T${}_g$ of copolymers. MAM
polymerizes itself to form water-soluable shell. It causes
surface electric density decreasing but increasing steric
hindrance of particles. The second part, MAA14\% latex
particles are used as seeds. GMA reacts with carboxyl group of
surface PMAA in order to reserve its double bond as reactive
site in the latter step. Various weights of styrene are dripped
slowly into seed latexes to react with seeds. The composite
particles are raspberry type proved by TEM photographs. They
are composed of a rubber core, a middle layer and PS shell
analyzed by DSC thermograms.
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