Kimio Imaizumi

Hydrocarbon polymers containing six-membered rings in the main chain. Microstructure and properties of poly(1,3-cyclohexadiene)

The relationship between the microstructure and the properties of poly(1,3-cyclohexadiene)s, obtained by living anionic polymerization with an alkyllithium/ amine system, and their hydrogenated derivatives are reported. The 1,2-bond/1,4-bond molar ratio of poly(1,3-cyclohexadiene) was determined by measuring 2D-NMR with the H-H COSY method. The glass transition temperature of poly(1,3-cyclohexadiene) was found to rise with an increase in the ratio of 1,2-bonds to 1,4-bonds or with an increase of the number average molecular weight. The 1,2-bond of the polymer chain gives a high flexural strength and heat distortion temperature. Hydrogenated poly(1,3-cyclohexadiene) has the highest T g (231°C) among all hydrocarbon polymers ever reported. 1,3-Cyclohexadiene-butadiene-1,3-cyclohexadiene triblock copolymer and 1,3-cyclohexadiene-styrene-1,3-cyclohexadiene triblock copolymer have high heat resistance and high mechanical strength.

Microphase‐separated structure of 1,3‐cyclohexadiene/butadiene triblock copolymers and its effect on mechanical and thermal properties

We report the effect of microphase-separated structure on the mechanical and thermal properties of several poly(1,3-cyclohexadiene-block-butadiene-block-1,3-cyclohexadiene) triblock copolymers (PCHD-block-PBd-block-PCHD) and of their hydrogenated derivatives: poly(cyclohexene-block-ethylene/butylene-block-cyclohexene) triblock copolymers (PCHE-block-PEB-block-PCHE). Both mechanical strength and heat-resistant temperature (ex. Vicat Softening Temperature: VSPT) tended to increase with an increase in the 1,3-cyclohexadiene (CHD)/butadiene ratio. On the other hand, heat resistance of the hydrogenated block copolymer was found to be higher than that of the unhydrogenated block copolymer. However, the mechanical strength was lower than those of the unhydrogenated block copolymer with the same ratio of CHD to butadiene. To clarify the relationship between the higher order structures of those block copolymers and their properties, we observed the microphase-separated structure by transmission electron microscope (TEM). Hydrogenated block copolymers were found to have more finely dispersed microphase-separated structures than those of the unhydrogenated block copolymers with the same CHD/Bd ratios through the use of TEM and the small-angle X-ray scattering (SAXS) technique. Those results indicated that the segregation strength between the PCHE block sequence and the PEB block sequence increased, depending on hydrogenation of the unhydrogenated precursor.

Block Copolymers Containing Cyclohexane Rings in the Main Chain-Behavior of Polymer Chain at a High Temperature

ポリマー鎖中のシクロヘキサン環の効果を調べるために, ポリシクロヘキサン (PCHE) -ポリ (エチレン/ブチレン) (PEB) -PCHEブロックコポリマーとポリスチレン (PSt) -PEB-PStブロックコポリマーを合成し, 高温雰囲気下における特性を調べた. 空気中, 100℃雰囲気下で1000時間経過したPSt-PEB-PStブロックコポリマーは黄褐色に変色し, PCHE-PEB-PCHEブロックコポリマーには動的粘弾性の変化が観察された.