title: Organogelation behavior and thermal properties of supramolecular polymer network composed of carboxy- and pyridyl-terminated 4-arm star-shaped ε-caprolactone oligomers.
abstract: Carboxy-terminated 4-arm star-shaped ε-caprolactone oligomers (Tetra-SA-CLO, Tetra-PA-CLO, and Tetra-TCPA-CLO) were synthesized by the reactions of hydroxy-terminated 4-arm star-shaped ε-caprolactone oligomers (Tetra-OH-CLO) having the degree of polymerization per one oligocaprolactone chain, n=3 and 5 with succinic anhydride, phthalic anhydride, and 2,3,4,5-tetrachlorophthalic anhydride, respectively. As a pyridyl-terminated analog, nicotinate-functionalized 4-arm star-shaped ε-caprolactone oligomer (Tetra-NA-CLO) was synthesized by the esterification reaction of Tetra-OH-CLO with nicotinic acid. All mixtures of the carboxy- and pyridyl-terminated analogs became thermoreversible organogels in N,N-dimethylformamide and nitromethane at around 15°C. The (1)H NMR and FT-IR analyses of the mixtures revealed the formation of hydrogen-bonded polymer network. The glass transition and cold crystallization temperatures of the mixtures were higher than the values estimated from those of the single components.
authors.affiliation: Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, Narashino, Chiba, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Nakamura
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Chu
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Shimasaki
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Shibata