About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Paper
Syntheses of Acetophenone Eno1 Ester Polymers and Their Conversion to Poly(phenylacetylenes)
Abstract
α-Acetoxystyrene (ACOST), 4-methylene-4H-1,3-benzodioxin-2-one (MBDOON), and 3-methylenephthalide (MP) readily undergo radical polymerization although they are α-substituted styrene derivatives. While poly(α-acetoxystyrene) (PACOST) is syndiotactic-rich due to the severe steric hindrance, the α,α-cyclic analogues are almost perfectly atactic (heterotactic-rich), indicating that the cyclization reduces the steric hindrance. PACOST and poly(4-methylene-4H-1,3-benzodioxin-2-one) (PMBDOON) release acetic acid and carbon dioxide upon heating to 200°C, being converted to poly(phenylacetylene) (PPA) and poly((o-hydroxyphenyl)acetylene) (PHOPA), respectively. PPA thus obtained has a trans structure. The thermolysis temperature can be lowered to ca. 100°C by generating a strong acid in the PACOST film through photolysis of a sulfonium salt cationic photoinitiator. PPA produced by acidolysis at the lower temperature contains a significant amount of cis sequences. PMBDOON can be also converted to PHOPA by heating the polymer powder with an acid at ca. 100°C. However, thermolysis and acidolysis of PACOST and PMBDOON are accompanied by depolymerization. In contrast, poly(3-methylenephthalide) (PMP) is very stable toward thermolysis and acidolysis. © 1990, American Chemical Society. All rights reserved.