Methylene-hydantoin and Related Compounds. II. Poly-5-methylene-hydantoin and Poly-α-aminoacrylic Acid

Abstract 5-Methylene-hydantoin was polymerized easily by free radical initiators, and showed a higher reactivity in copolymerization with styrene. From the copolymerization of styrene (M1) and 5-methylene-hydantoin (M2), the monomer reactivity ratios, r1 and r2, were found to be 0.03 and 24, while the Q and e values in Alfrey-Price’s Q-e scheme were found to be 21 and −0.23, respectively. As is shown by the large Q value, the high reactivity of 5-methylene-hydantoin is based on the high resonance stabilization of its radical, a stabilization which results from the conjugation system. This was also confirmed by a study of the ultraviolet spectrum. Poly-5-methylene-hydantoin showed electrolytic behavior in its solubility and solution viscosity. This property is due to the dissociation of NH at the 3 position of the hydantoin group. The polymers of 3-methyl-5-methylene-hydantoin and 3-phenyl-5-methylene-hydantoin were observed to show very weak acidities, resulting from the NH at the 1 position. Poly-α-aminoacrylic acid was obtained by the alkaline hydrolysis of poly-5-methylene-hydantoin. This polymer was soluble in water, and showed an unusual amphoteric behavior in solution viscosity.