ISSN:
0360-6376
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The photocycloaddition of simple olefins to poly(4-vinylbenzophenone) (PVB) and poly(styreneco-4-vinylbenzophenone) (PS-VB) was studied in benzene solution and in the solid polymer. In solution oxetane yields of 61-82% were obtained with di-, tri-, and tetrasubstituted olefins, which are visualized as capable of giving a radical on a 3° carbon atom in the biradical preceding ring closure to form the oxetane. Photocycloaddition of isobutene to PVB and PS-VB occurs in solid polymer films to more than 90% conversion of the polymer ketone. Quantum yields of oxetane formation are 0.013 ± 0.003 on irradiation at 366 nm, independent of film thickness between 1.9 and 10.6 μm and of temperature between 23 and 65°C. The absence of a pronounced effect of the polymer glass transition on the efficiency of the cycloaddition in PVB suggests that large-scale molecular motion is not required by this solid-state photoreaction. Crosslinking by photochemical cycloaddition was demonstrated in mixed films of PVB and squalene, a polyfunctional olefin.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1980.170180217
