1995 Fiscal Year Final Research Report Summary
Synthesis of Novel Block Copolymers Containing Liquid Crystalline Segments by Anionic Living Polymerization
| Project/Area Number |
06651020
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子合成
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
HIRAO Akira Tokyo Institute of Technology, Faculty of Engineering Associate Professor, 工学部, 助教授 (00111659)
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| Project Period (FY) |
1994 – 1995
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| Keywords | liquid crystalline / block copolymer / anionic living polymerization / microphase separation / domain structure / 6- (p-methoxybiphenoloxy) methacrylate / 6- (p-cyanobiphenoloxy) -methacrylate |
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| Research Abstract |
Anionic polymerization of 6- (p-methoxybiphenoloxy) methacrylate (1) and 6- (p-cyanobiphenoloxy) methacrylate (2) were carried out in THF with various initiators. Under specified conditions, both (1) and (2) underwent anionic living polymerization to afford quantitatively the polymers of well-regulated molecular weights and of extremely narrow molecular weight distributions (Mw/Mn<1.1). By using these living polymers, novel well-defined block copolymers of (1) or (2) with stirene or methyl methacrylate were successfully prepared. Their structures are AB,BA,ABA and BAB types of block copolymers. They possessed well-controlled molecular weights and compositions and narrow molecular weight distributions. In order to investigate systematically the relationship between thermotropic transition behavior and polymer structure, homopolymers with different molecular weights (3 000-30 000) and block copolymers with different molecular weights (5 000-100 000) and compositions (20-80mol%) were prepared.
In a series of poly (1) s, the thermotropic transition behavior between crystal, smectic A,and isotropic phases was observed to be examined with a function of molecular weight. With poly (2) s, nematic liquid crystalline phase was observed. The temperature range showing liquid crystalline phase was also influenced by the molecular weight of poly (2). In the block copolymers of stirene and (1), microphase separation due to liquid crstalline and amorphous polystirene blocks was observed by electron microscopy and small-angle X-ray methods. Decrease of period of microdomain with temperature was first found in the temperature range showing liquid crystalline phase. A new model was proposed for this. On the otherhand, this phenomenon was not observed in the block copolymers of stirene and (2), although these block copolymers were microphase-separated.
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Research Products
(2 results)
