The thermotropic liquid crystalline copolymers were prepared by melt polymerization using p-acetoxybenzoic acid (p-ABA) and terephthalic acid (TPA) as mesogenic monomers, poly(ethylene terephthalate) (PET) to give a flexible linkage, and 2,7-diacetoxy naphthalene (2,7-DAN) as a dissymmetrical monomer. The composition of these monomers was varied as a means of manipulating thermal and dynamic mechanical properties. The polymers with inherent viscosities near or above 1.6 that were melt processible in the temperature range of 210 ∼ 290℃ were obtained. Highly anisotropic melts were observed indicating the presence of a nematic mesophase. The glass transition temperature increased with increasing contents of mesogenic units and 2,7-DAN. The temperatures at which the storage modulus drastically dropped off increase with increasing mesogenic units and 2,7-DAN.

단량체 p-acetoxybenzoic acid (p-ABA), terephthalic acid (TPA), low inherent viscosity (IV) poly(ethylene terephthalate) (PET) 및 2,7-diacetoxy naphthalene (2,7-DAN)을 사용하여 여러 조성의 열방성 액정고분자를 제조하여 화학조성이 그 성질에 미치는 영향을 조사하였다. IV가 1.6이상이고 210∼290℃에서 용융가능한 열방성 액정 공중합체를 얻었다. 얻어진 공중합체는 230℃에서부터 최소 320℃까지의 넓은 온도범위까지 nematic mesophase를 보였다. 유리전이온도 및 저장탄성율이 급격히 감소되는 온도는 mesogenic 단위 및 2,7-DAN 함량의 증가에 따라 현저하게 증가하였다.

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