ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
By the thermistor method, we measured rates of copolymerization of St(styrene)-VA(viny1 acetate) and MM(methy1 methacrylate)-St for various mixing ratios of the two monomers. In the St-VA system, the large difference between the reactivity ratios of the two monomers causes a large error limit in values of 4, so that we could not find any essential regularities in the variation of 4 with successive mixing ratios. In the MM-St system, however, where the difference of the two reactivity ratios is not so large, we can determine the values of 4 more precisely and obtain a concrete confirmation of Arlman's theory. As a result, we conclude that, for the MM-St system (at. 24°C.), the termination constants for mixed radicals are larger than those for homogeneous radicals, and, furthermore, that the rate constant for a normal cross-termination reaction is about 3 times larger than that of the cross-termination reaction having a penultimate unit.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1959.1203713221
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