ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Copolymers from styrene and a mixture of p- and m-chloromethylstyrene were reacted with sodium cyclopentadienide in THF and precipitated in methanol at temperatures lower than -20°C to obtain soluble cyclopentadienylated polymers. Due to extensive gelation, the content of cyclopentadienyl groups could not be increased to more than 4 mol-% except with extremely low molecular weight polymers. An improved method, in which the copolymer was cyclopentadienylated in the presence of metallic sodium, gave soluble polymers with up to 29 mol-% cyclopentadienyl groups. Pendant cyclopentadienyl groups undergo Diels-Alder/retro-Diels-Alder addition to give thermoreversible cross-linked polymers. The amount of gel fraction of a 4 mol-% cyclopentadienylated polymer as a function of the heating time was examined in the temperature range of 40-80°C. The DSC curve of a 29 mol-% cyclopentadienylated polymer showed an exothermic peak due to the Diels-Alder reaction and an endothermic peak starting around 390°C, a temperature higher than that found for the degradation of polystyrene.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1985.021860304
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