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热致型光敏液晶高分子在液晶场中光交联反应的研究 总被引:1,自引:0,他引:1
研究了具有肉桂酸酯侧链基的热致型液晶高分子的光交联行为.结果表明,在20min紫外光照射的条件下,形成液晶相的液晶高分子膜的光交联凝胶百分率要明显高于尚未形成液晶相的同种高分子膜.对形成液晶相的高分子膜,在环境温度低于液晶各向同性温度T时,温度对光交联凝胶百分率的影响甚微.这表明,由于液晶高分子中致介单元的聚集和有序排列形成的微区结构也影响了大分子链侧基肉桂酸酯的聚集状态.从而使其光化学性质发生变化. 相似文献
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本文介绍了几种具有中介相结构及非中介相结构的双-甲亚胺的模型化合物及三种芳族聚亚胺的合成。研完了分子链的柔性、分子结构和共轭度对中介相转变温度的影响。 相似文献
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A wholly-aromatic thermotropic liquid crystalline polymer (WATLCP) composed ofp-hydroxybenzoic acid (HBA), 4,4'-dihydroxy bisphenyl (BP), terephthalic acid (TPA),m-phthalic acid (MPA) was synthesized. It was symbolized by BP-LCP. Using a simi-lar method, a new copolymer BP-PSF was prepared. BP-PSF has a semi-flexible chainpolysulfone and a rigid-rod chain like BP-LCP. By FT-IR, polarizing microscope and DSCtechnique, the structures and properties of BP-LCP and BP-PSF were studied. 相似文献
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固态后缩聚方法合成高分子量的含磷热致性液晶共聚酯 总被引:1,自引:0,他引:1
为了获得较高分子量的具有高阻燃性的热致性液晶高分子,通过固态聚合方法合成了一种基于对羟基苯甲酸、对苯二甲酸、乙二醇和含磷菲环取代二酚的高热稳定性、较低相转变温度和宽的液晶相转变温度范围的含磷液晶共聚酯(BDQTEP),并对该含磷液晶共聚酯预聚物(pre-BDQTE)在不同固态聚合条件下获得的聚合物热性能和液晶性进行了研究.对其固态反应速率控制进行了初步的探讨,当反应温度为235℃时,固态聚合反应较为理想.在聚合的初始阶段,共聚酯特性黏数[η]、黏流温度Tf和羧基浓度[COOH]均随聚合时间而明显变化,但在6 h后变化较小,几乎不变.通过固态后缩聚,将熔融聚合获得的特性黏数[η]=0.44 dL/g的含磷液晶共聚酯BDQTE的特性黏数提高了近两倍. 相似文献
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The morphological features of a side-chain liquid crystalline polymer during the mesophasetransitions were investigated by using the DSC technique. The polymer used was polyacrylate with mesogensof three benzene rings attached to the main chain through a flexible spacer. A special two-phase texture wasobserved in the transition temperature range. Similar to main-chain liquid crystalline polymers the transitionprocess of the side-chain liquid crystalline polymer was composed of an initiation of the new phase at localplaces of the old phase matrix and a growth process of the new phase domains. 相似文献
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热致液晶聚合物的可纺性与其在基体树脂中的成纤 总被引:6,自引:1,他引:6
热致液晶聚合物的可纺性与其在基体树脂中的成纤何嘉松,张洪志(中国科学院化学研究所工程塑料国家重点实验室北京100080)关键词热致液晶聚合物,熔融可纺性,高分子共混物,原位复合,亚微米增强用热致液晶聚合物(TLCP)对热塑性树脂产生亚微米级增强作用的... 相似文献
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A series of novel mesogenic polyamides containing a flexible pendent side group wassynthesized by solution condensation polymerization. The new monomers, diacids and di-amines containing flexible elements of diferent lengths, were also synthesized and character-ized by ~1HNMR, mass spectroscopy and elemental analysis. The polymers were character-ized by viscosity measurements, differential scanning calorimetry (DSC), X-ray diffiactionand polarizing optical microscopy These studies revealed that polyamides containingflexible elements of a sufficient length exhibited thermotropic liquid crystalline(LC) pro-perties. The melting temperatures of this series of polymers were particularly sensitive tothe length of the flexible segment on the main chain and that of the flexible pendent esterside chain. Lyotropic LC behaviours were also observed in solution. 相似文献
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合成了氮上完全取代的邻苯二甲酰化壳聚糖 (PhthCS) .用DSC研究了PhthCS DMSO液晶溶液的热致相转变 .偏光显微镜和DSC测定都表明临界浓度为 43wt% .在浓度高于 43wt%的溶液的DSC曲线中观察到了除了液晶 各向同性液体转变 (清亮点 )外还有一个明显的凝胶 溶胶转变 .凝胶 溶胶转变温度和转变焓均比文献报道的不规则取代的N 邻苯二甲酰化 O 乙酰化壳聚糖大得多 ,可见取代的规整性对凝胶 溶较转变有很大的影响 .根据DSC研究结果绘制了PhthCS DMSO体系的相图 相似文献
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用4种热致液晶聚合物分别与聚丙烯,聚对苯二甲酸丁二酯,聚碳酸酯,聚醚砜和聚砜搭配,在各聚合物对的“加工窗口“温度范围内熔融共混并挤塑得到6种共混物。藉流变仪,扫描电子显微镜,偏光显微镜,动态力学谱仪等重点研究了原位复合材料中微纤结构的形成,组分特性,熔体粘度,挤塑温度和浓度等因素对各向异性结构形成的贡献,以及液晶聚合物对聚合物结晶的诱导作用和两相间的相互作用。 相似文献
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β 氯乙基缩水甘油醚 (GCE)和GCE/羟丁基乙烯基醚 (HBVE)分别通过阳离子聚合、光引发共聚合 ,获得两种聚醚 ,然后再分别与 4 硝基 4′ 羟基 (NHS)反应 ,制备了两种侧链含生色团的液晶聚合物(PSEG、PSV) .用FTIR、1H NMR和EA对其化学结构及生色团含量进行了表征 ,以POM、DSC、TGA和WAXD对聚合物介晶相转变温度、织构、热稳定性及相行为进行了研究 .结果表明 ,这类聚合物属向列型热致双向性液晶 ,液晶相转变温度较低、范围较宽 ;聚合物热稳定性较好 ,开始分解温度在 30 0℃以上 . 相似文献
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Five kinds of side chain liquid crystalline polymers with a chiral component in the pendant group were synthesized and characterized by GPC, polarizing microscopy, DSC, X-ray diffraction ano Dielectric Relaxation Spectroscopy. The liquid crystalline behaviour of the polymers is affected by the length of flexible spacer, which links the mesogenic side chain to the polymer backbone and mesogenic moiety. The characteristic of smectic phase is observed for all the polymers. 相似文献
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热致性液晶乙基纤维素和聚丙烯共混物的结构与性能 总被引:5,自引:0,他引:5
乙基纤维素(EC)和聚丙烯共混物沿取向方向有明显的絮条状结构,EC含量增加使Tc提高,△H和Tm有所降低,共混物的成核能力降低,结晶度下降,(110)晶面尺寸减小,(040)晶面尺增大。EC/PP共混物的ηa、τa值更接近于PP结果。力学测定结果给出,EC/PP=10/90的共混物抗张模量有所增加。 相似文献