Y. Oshiro, Y. Shirota, H. Mikawa
Aug 1, 1973
Citations
0
Influential Citations
7
Citations
Journal
Polymer Journal
Abstract
The 9-anthraldehyde acetal of poly(vinyl alcohol) (abbreviated hereafter as acetal) was synthesized from poly(vinyl alcohol) and 9-anthraldehyde with hydrochloric acid as a catalyst in dioxane-water (60:40), and the kinetics of the acetalization was examined. The initial rate of the reaction was first order with respect to the initial concentration of poly(vinyl alcohol), 9-anthraldehyde, and acid. The apparent activation energy was calculated as 3.4 kcal/mol. The maximum degree of acetalization did not exceed 43.8%. The low degree of acetalization was interpreted in terms of steric hindrance by the anthracene ring. Acetylation of the acetal gave acetylated acetal which was easily soluble in organic solvents, although the original acetal was almost insoluble in organic solvents. The charge-transfer complex of the acetylated acetal with tetracyanoquinodimethane (TCNQ) showed a charge-transfer absorption band with λmax730 nm in methylene chloride at room temperature. The equilibrium constant (K) was evaluated as 15.7 l/mol. The dielectric constants (ε) measured at 1 kHz were 3.1 for the acetylated acetal film, and 2.9 for the charge-transfer complex of the acetylated acetal with TCNQ.