ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
True 100% grafted polymers were prepared in a two-stage emulsion polymerization process. Microgels of styrene crosslinked with divinylbenzene, methyl acrylate crosslinked with divinylbenzene, and acrylonitrile crosslinked with methylene-bisacrylamide were used as first stage polymers, and the grafting of styrene and acrylonitrile were studied. The polymers were analyzed as microsols by limiting viscosity number and by ultracentrifuge measurements. In the ultracentrifuge the quantitative separation of crosslinked particles from linear polymers was demonstrated. From a study of the polymerization conditions which result in a single sedimenting component in the ultracentrifuge, 100% grafted polymers were synthesized. The results indicated that in order to obtain 100% grafting initiation must be by free radicals present in the polymer particles with none from residual catalyst or by thermal initiation. The existence of polymeric free radicals of lives greater than 100 days is demonstrated.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1958.1202811715
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