ISSN:
0360-6376
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The thermal degradation of poly(cyclopentylidene carboxylate) and poly(cyclohexylidene carboxylate) has been studied over the temperature range 200-500°C by using a combination of kinetic and analytical techniques. The results obtained indicate the simultaneous operation of mechanisms previously observed with different compounds in the series. Thus kinetic studies by thermogravimetric analysis and characterization of the products formed suggest the occurrence of an essentially first-order hydrogen abstraction process with superimposed random scission reactions in the early stages. The main products are cyclopenten-1-carboxylic acid and cyclohexen-1-carboxylic acid, respectively. This corresponds to the behavior previously observed in the degradation of poly(3-pentylidene carboxylate). On the other hand, in-line pyrolysis directly linked to a gas chromatograph clearly indicates the production of cyclopentanone and cyclohexanone and, more importantly in the case of poly(cyclopentylidene carboxylate), the formation of dicyclopentyl glycollide. The appearance of these products in addition to the unsaturated acids suggests that some degradation occurs by the intramolecular ester-interchange process previously postulated for poly(methylene carboxylate) and poly(isopropylidene carboxylate). The associated thermodynamic parameters and relative quantities of the different products observed by gas-chromatographic methods indicate that the hydrogen-abstraction process predominates.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1978.170160126
Permalink
