Facile synthesis of poly(4-hydroxy styrene) from polystyrene

Abstract

A facile methodology to modify polystyrene, to incorporate alkali soluble hydroxy groups, is reported. Polystyrene of well-defined number-average molecular weights in the range of 3000 to 50,000 were prepared by suspension polymerization at 80°C by varying the relative mole ratio of carbon tetrachloride, used as chain transfer agent. Polystyrenes were acetylated; the acetyl groups were converted to acetoxy groups, by Baeyer-Villiger oxidation, and hydrolyzed in a nonaqueous alkaline medium to generate hydroxy groups. The extents of modifications were monitored by infrared spectroscopy. The glass transition temperatures of poly(4-acetylstyrene-co-styrene), poly(4-acetylstyrene-co-4-acetoxystyrene-co-styrene), and poly(4-hydroxystyrene-co-4-acetylstyrene-co-styrene) were 107,134, and 142°C, respectively. The polymers were evaluated in photoresist formulations. © 2004 Wiley Periodicals, Inc.