Itaru Natori

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.

Hydrocarbon Polymers Containing Six-Membered Rings in the Main Chain : Polymerization of Cyclic Conjugated Dienes Using Rare-Earth Metal Catalysts

希土類金属触媒による1, 3-シクロヘキサジエン (1, 3-CHD) の重合反応を研究した. ネオジウム (III) イソステアレート (Nd (ISA) 3) /変性メチルアルミノキサン (MMAO) /エチルアルミニウムセスキクロライド (EASC) 触媒システムでは, 1, 3-CHDの配位重合が進行した. 触媒活性は, Nd, Ce, Gd, Sm, Ybの順であった. これらの触媒システムは, 新タイプの高分子主鎖に六員環を有する炭化水素系ポリマーを開発する可能性を有している.