热致液晶聚合材料加工研究

热致液晶聚合物是新近兴起的一种具有优异强度和弹性模量以及耐热性的热塑性新型材料,具有广阔的发展应用前景;目前国内对此材料的研究较少,缺乏相应的生产加工方法与经验。通过试验与特殊工程设计的验证,文章阐述了热致液晶聚合材料在实际生产过程中的具体加工方法与生产参数,验证了热致液晶聚合材料产品的工厂小批量制作的加工可行性。     

一种丙烯酸酯型侧链液晶高分子的合成及液晶性的研究

依据液晶分子结构理论,选择联苯基作为介晶基元,六亚甲基为柔性间隔基,合成了一种丙烯酸酯侧链型液晶高分子。对于合成的中间及目标产物通过FTIR、1HNMR等进行了结构的表征。对于聚合物采用GPC法测量了其分子量,并通过DSC、POM、XRD和计算机模拟等手段研究了其液晶性。研究表明合成的聚合物分子量-Mn=2523、-Mw=2826,具有较宽的温域(45.3～95.2℃),且为典型的近晶A相液晶。     

聚芳酯类热致液晶聚合物的研究进展

热致液晶聚芳酯(Thermotropic Liquid Crystalline Polyarylate,TLCP)是一类重要的热致液晶聚合物,具有优异的力学性能、良好的热稳定性、稳定的介电性能和灵活的可加工性等诸多优点.随着绿色化学和信息化时代的到来,TLCP将占据越来越广阔的市场.本文从聚合物制备、结构与性能以及工程...     

VO2/FTO复合热致变色薄膜的制备及其光学特性

在掺氟的SnO2(FTO)导电玻璃衬底上采用直流磁控溅射的方法室温沉积纯钒金属薄膜,再在退火炉中经后退火工艺制备VO2/FTO复合热致变色薄膜,并对复合薄膜的结构及其光学特性进行研究.结果表明,导电玻璃上的FTO并没有改变VO2择优取向生长,但明显改变了VO2薄膜的表面形貌特征.与相同工艺条件下在玻璃衬底上制备的VO2薄膜相比,VO2/FTO复合薄膜的相变温度降低约18℃,热滞回线温宽收窄约4℃,相变前后的红外透过率分别约为42%和21%.说明复合薄膜既可明显降低相变温度和热滞宽度,又可增强VO2薄膜的红外调控能力.     

高性能热致液晶聚合物LCP基板卷材开发与应用

文章采用4-乙酰氧基苯甲酸（ABA）6-乙酰氧基-2-萘甲酸（ANA）共缩聚合加入4,4、二氨基二苯醚（ODA）聚醚酰亚胺（PEI）,通过刚性棒状大分子链受热熔融形成一种兼有固体和液体的部分性质的液晶态聚合物通过涂布延伸,二阶段溶浸聚合溶融缩聚制备LCP基板卷材。     

纳米胆甾型液晶材料的合成

经缩聚反应合成了纳米胆甾型液晶材料.通过改变手性组分含量、手性化温度以及调节分子间纳米级螺距,使聚合物表现出不同的光学和波谱性能.制备出了随入射光的入射方向和观察方向不同而色彩变化、表面均匀的样品.实验表明,该材料在印刷、装饰、防伪等领域有广阔的应用前景.     

纳米胆甾型液晶材料的合成

经缩聚反应合成了纳米胆甾型液晶材料.通过改变手性组分含量、手性化温度以及调节分子间纳米级螺距,使聚合物表现出不同的光学和波谱性能.制备出了随入射光的入射方向和观察方向不同而色彩变化、表面均匀的样品.实验表明,该材料在印刷、装饰、防伪等领域有广阔的应用前景.     

Synthesis of Nanowalled Polymer Microtubes Using Glass Fiber Templates

Covalently crosslinked flexible polymer microtubes with wall thicknesses of 1–3 nm, diameters of 2–10 μm, and lengths of 0.1–0.5 mm have been fabricated using glass wool and silica wool as templates. Fluorescent‐dye‐tagged polyamines were adsorbed onto the glass and silica templates and crosslinked by reductive amination with glutaraldehyde and sodium cyanoborohydride, then the templates were dissolved with hydrofluoric acid. Microtubes were prepared from polyallylamine (PAA), polyethyleneimine (PEI), and poly(iminohexamethylene) (PIH) labeled with sulforhodamine B. These flexible hollow structures were characterized by bright‐field and fluorescent optical microscopy and confocal laser scanning microscopy; they adopt open tubular conformations when suspended in water, and dry to give flat ribbons.     

液晶聚合物薄膜的介电性能

研究了两种液晶聚合物薄膜的介电性能。结果表明,液晶聚合物的介电常数随频率的增加而缓慢变小,高温下的介电常数较大。介电损耗在一定的温度范围内（室温至３５０℃）出现峰值,峰值位置随频率的增加向高温方向移动。     

Molecular Engineering of Mesogenic Constituents Within Liquid Crystalline Elastomers to Sharpen Thermotropic Actuation

Liquid crystalline elastomers (LCE) are stimuli-responsive materials with a distinguished mechanical response. LCE have been subject to numerous recent functional examinations in robotics, health sciences, and optics. The liquid crystallinity of the elastomeric polymer networks of LCE are largely derived from liquid crystalline monomer precursors. Recent reports have utilized commercially available liquid crystalline diacrylate monomers in chain extension reactions to prepare LCE. These reactions have been largely based on monomeric precursors originally to enhance the and thermal stability of optical films. Here, it is demonstrated that preparing LCE via a liquid crystalline diacrylate with reduced mesogen–mesogen interaction enhances and sharpens the thermotropic actuation of these materials. Robust composition-response correlations are demonstrated in LCE prepared by three common synthetic methods. The enhanced thermotropic response of LCE prepared from this precursor increases the thermomechanical efficiency by sixfold. Accordingly, this work addresses important limitations in utilizing the thermal response of LCE in robotics, health care, and consumer goods.     

Light-Responsive Programmable Shape-Memory Soft Actuator Based on Liquid Crystalline Polymer/Polyurethane Network

Liquid crystalline polymers (LCPs), especially liquid crystalline elastomers (LCEs) can generate ultrahigh shape change amplitude but has lower mechanical strength. Although some attempts have been tried to improve the mechanical performance of LCE, there are still limitations including complicated fabrication and high actuation temperature. Here, a versatile method is reported to fabricate light-driven actuator by covalently cross-linking polyurethane (PU) into LCP networks (PULCN). This new scheme is distinct from the previous interpenetrating network strategy, the hydrogen bonds and covalent bonds are used in this study to improve the miscibility of non-liquid-crystalline PU and LCP materials and enhance the stability of the composite system. This material not only possesses the shape memory properties of PU but shows shape-changing behavior of LCPs. With a shrinkage ratio of 20% at the phase transition temperature, the prepared materials reached a maximum mechanical strength of 20 MPa, higher than conventional LCP. Meanwhile, the resulting film shows diverse and programmable initial shapes by constructing crosslinking density gradient across the thickness of the film. By integration of PULCN with near-infrared light-responsive polydopamine, local and sequential light control is achieved. This study may provide a new route for the fabrication of programmable and mechanically robust light-driven soft actuator.     

一种超支化分子液晶性的研究

超支化聚酯是以3，5－二羟基甲苯和3，5－二羟基苯甲酸为原料，采用“一锅煮”的方法合成而得。通过热示差、偏光显微镜、X衍射等手段全面地探讨了聚酯的液晶性。表明该聚合物在83.4-134.6℃较宽的温度区间表现出典型的向列型液晶性质。     

Study of Synthesis of Nano-Cholesteryl liguid Crystalline Polymer material

Nano-cholesteryl liguid crystal material is synthesized by condensation polymerization. Changing the chiralcomponents content and chiral temperature and ad usting the intermolecular nano-pitch lead the polymer to different optical and spectrum behaviour. The sample is synthesized, which has even surface. Its colour changes with the incident ray angle and observation situation. The eXperiments show that the material has an potential application in the field of printing, adornment, false proofand so on.