In the present study thermal transition behavior, crystallization kinetics and crystal structure through X-ray diffraction patterns were investigated for the oligomers and oligomer blends of smectic and nematic oligomers.
Three kinds of monomers were prepared (SP10, NP6, NP10 monomer) from decanediol, hexanediol and hydroquinone and p-hydroxybenzoic acid. And by reacting the monomers with TPC in various stoichiometric reactant ratio, three kinds of oligomers (SP10, NP6, NP10 oligomer) having various molecular weight as well as homopolymers were prepared,and for the comparison of X-ray pattern with the prepared blend a kind of block copolymer was prepared.
For the prepared oligomers, homopolymers and blends, $T_m$, $T_i$, $T_c$ and $T_{deiso}$ were measured by DSC and polarizing microscope. The $T_m$ and $T_i$ increased as M.W increased.
To obtain informations on the crystal growth, the Avrami exponents based on constant nucleation density were calculated using isothermal DSC method. Avrami exponent changed from 2 to 3 as the molecular weight of the SP10-oligomer increased, 1 to 2 as molecular weight of the NP6-oligomer increased.
The Wide-Angle and Small-Angle X-ray diffractograms and photographs for quenched (from their liquid crystal state) powder samples were analyzed to obtain the inter-chain distance in their liquid crystal state.
The crystallinity was low and inter-chain distance in the mesophase was in the range of 4-6Å, and no significant differences were observed in diffraction patterns of oligomers and homopolymers. small-angle was nearly the same or a little smaller than the fully extended chain length.
이 논문에서는 스메틱 메조겐과 네마틱 메조겐으로 이루어진 올리고머와 올리고머 블랜드의 열적거동, 결정화속도 그리고 X-ray 산란 패턴이 연구 되어졌다.
다이올과 테레프탈로일 다이클로라이드로부터 세종류의 올리고머와 호모폴리머를 합성하였으며 올리고머로부터 올리고머 블렌드와 한종류의 블락코폴리머를 합성하였다.
올리고머와 호모폴리머의 열전이온도는 분자량이 증가함에 따라 증가하였다.
결정화속도에 있어서 아브라미 상수는 스메틱(SP10-Oligomer) 의 경우 분자량이 증가함에 따라 2에서 3 으로 증가하였으며 네마틱(NP6-Oligomer)의 경우 1 에서 2 로 증가하였다.
X-ray 산란 패턴으로부터 올리고머와 호모폴리머의 스메틱성이나 네마틱성 그리고 분자량에 관계없이 결정구조의 유사성이 관찰되었으며 액정상에서의 체인간격은 4-6Å임이 관찰되었다 그리고 결정구조의 C-axix 의 길이는 완전히 펼쳐진 체인의 반복단위의 길이보다 조금 작거나 거의 같음도 관찰되었다.
