Termination and other processes in the polymerization of p-methoxystyrene and 2,2-dideutero-p-methoxystyrene

✍ Scribed by W. Brendlein; G.S. Park

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 338 KB
• Volume: 11
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(75)90052-x

✦ Synopsis

Abstrnct--The uncatalysed thermally initiated free radical bulk polymerization of p-methoxystyrene and 2,2-dideutero-p-methoxystyrene (65% deuterated) have been studied at 80, 100 and 120 °.

Both the rate of polymerization and the degree of polymerization are increased by deuteration. as would be expected from the deuterium kinetic isotope effect if disproportionation plays a part in the radical termination process. The effect of deuteration is least at the highest temperature, but it is shown that this does not mean that the extent of disproportionation decreases with increasing temperature.

From a comparison of the effect of deuteration on the polymerization rate with its effect on the degree of polymerization, it is concluded that the transfer constant to monomer is less for the deuterated material than for the undeuterated material. It is suggested that the transfer process probably involves the donation of a deuterium or hydrogen atom from the growing radical to the monomer.