ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Highly viscous systems made up of 70 wt% epoxy resin dissolved in 30% monomer mixture of styrene and acrylic monomers were irradiated with 1.5 MeV electrons to initiate graft copolymerization. The obtained product of graft copolymer mixture was fed into a mixed solvent of n-butanol and cyclohexanone, and was heated 2 h at 70°C to form a predispersion. Then aqueous solution of 2-dimethylaminoethanol or ethanol was added to the predispersion, thus giving a stable dispersion in water or in ethanol. The particle diameter of the aqueous and ethanol dispersions is practically the same, thus suggesting that polymer particles are virtually generated during the predispersing procedure, and at this step the size of the particles is actually determined. The particle diameter increases inversely proportional to the polymer concentration in the predispersion. Furthermore, the particle diameter shows a tendency to decrease with an increase in the hydrophilicity of monomers used in the graft copolymerization. The stopped-flow measurement, on the other hand, reveals a characteristic pH dependence of the dispersion stability to the addition of NaCl. This result is interpreted based on a particle model consisting of a particle core of epoxy resin and its surrounding layer of acrylic copolymer.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1987.070340610
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