ISSN:
0449-2951
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Copolymerizations of styrene with p-tert-butyl-, o-methyl-, 2,6-dimethyl-, and p-fluorostyrene were carried out with an alkyl aluminum - titanium trichloride catalyst. Overall composition of the product indicated that substituted styrenes were less reactive than expected for a conventional free-radical or ionic mechanism in solution. This fact led to a suggestion of a special steric interaction of the penultimate monomeric unit in the propagation step for this heterogeneous system. A styrene-p-tert-butylstyrene copolymer was fractionated, showing that it was composed of two or more copolymers of different compositions. The similar situation holds for the other cases except for 2,6-dimethylstyrene, which did not homopolymerize and did not copolymerize. The result was explained by the assumption of either multiactivity of the catalyst due to differences in site activity or a diffusion-controlled process.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1963.100010430