引入离子基团改善聚苯乙烯和热致液晶聚合物的相容性 Ⅰ热性能和形态

ＤＳＣ和ＳＥＭ研究结果表明聚苯乙烯（ＰＳ）与一种热致液晶聚合物（ＬＣＰ）（ＰＨＢ／ＰＥＴ（６０／４０）共聚酯）完全不相容．共混体系具有与组分无关的Ｔｇ，并且表现出明显的两相结构．将ＰＳ进行化学改性（引入磺酸基团）制备成磺化聚苯乙烯（ＳＰＳ），随中和盐离子的变化有：酸式、Ｌｉ、Ｎａ、Ｚｎ和Ｍｎ盐五种形式．用ＤＳＣ和ＳＥＭ对ＬＣＰ与ＳＰＳ共混物的热性能和形态进行了分析和表征．共混体系有一个与组成相关，且明显低于纯ＳＰＳ的Ｔｇ．这表明了ＰＳ与ＬＣＰ的相容性因为磺酸基团的引入而得到了改善．同时用Ｆｏｘ方程计算了ＬＣＰ的Ｔｇ．当ＳＰＳ含量较低时（不大于５０％）在各个共混体系中，所估算的ＬＣＰ的Ｔｇ相互吻合．表明共混体系满足Ｆｏｘ方程的前提条件，即ＬＣＰ与ＳＰＳ形成相容体系．当ＳＰＳ含量较低时（２５％），ＬＣＰ／ＳＰＳ的共混物为较均一体系，断面光滑；而ＳＰＳ含量较高时，在脆断面可以观察到纳米级的颗粒．电子能谱分析证明了这些颗粒是ＳＰＳ负离子的聚集体．     

液晶共聚物与PSF原位复合的界面研究

合成了两种热致性液晶共聚酯ＢＰ—ＬＣＰ和ＳＤＰ—ＬＣＰ，对其熔融指数、取向性作了考察。选用基体聚砜（ＰＳＦ）与液晶共聚酯进行熔融共混，得原位复合材料。ＳＥＭ断口形态显示了两种液晶在基体中不同的成纤性，并显示出两相的不相容性。采用ＦＴ—ＩＲ方法分析了液晶共聚酯与ＰＳＦ界面间的分子相互作用。进一步研究发现在ＰＳＦ／ＢＰ－ＬＣＰ原位复合体系中加入含ＰＳＦ和ＢＰ－ＬＣＰ的嵌段共聚物，其相容性得以改善     

引入离子基团改善聚苯乙烯与热致液晶聚合物的相容性 Ⅱ用FTIR研究分子间特殊相互作用

向聚苯乙烯（ＰＳ）中引入磺酸基团可以有效地改善ＰＳ与一种热致液晶聚合物（ＬＣＰ）之间的相容性．用溶液共混的方法制备了ＰＳ和磺化聚苯乙烯（ＨＳＰＳ）与ＬＣＰ的共混物．用ＦＴＩＲ以及红外光谱的合成技术对ＬＣＰ共混体系进行了表征．共混物中组分聚合物特征吸收的位置和谱图的形状表明在ＬＣＰ与ＰＳ分子间没有相互作用发生，而在ＬＣＰ与ＨＳＰＳ分子间则存在较强的相互作用．谱图差减技术确认了ＬＣＰ分子中ＣＯ与ＣＯ基团和ＨＳＰＳ中的磺酸基团参与了相互作用，使得这些基团的特征吸收发生了偏移．     

AB／C型嵌段共聚物／均聚物的共混体系的相容性和形态研究（Ⅲ）──共混物的焓弛豫

嵌段共聚物ＰＩ－ｂ－ＰＭＭＡ和不同羟基含量的改性聚苯乙烯ＰＳ（ＯＨ）组成的共混物因ＰＭ－ＭＡ嵌段和ＰＳ（ＯＨ）间的玻璃化转变相当接近而不能用通常的ＤＳＣ法判别其相容性。通过共混物的焓弛豫，得到相容性明确的ＤＳＣ判据，且与电镜观察结果一致。共混物中的Ｔｇ增宽效应可通过江明等提出的链密度梯度模型解释。     

AB／C型嵌段共聚物／均聚物的共混体系的相容性和形态研究（…

嵌段共聚物ＰＩ－ｂ－ＰＭＭＡ和不同羟基含量的改性聚苯乙烯ＰＳ（ＯＨ）组成的共混物因ＰＭ－ＭＡ嵌段和ＰＳ（ＯＨ）的玻璃化转变相当接近而不能用通常的ＤＳＣ法判别其相容性，通过共混物的焓弛豫，得到相容性明确的ＤＳＣ判据，且与电镜观察结果一致，共混物的Ｔｇ增宽效应可通过江明等提出的链密度梯度模型解释。     

引入离子基团改善聚苯乙烯和热致液晶聚合物的相容性Ⅰ.热性能和形态

ＤＳＣ和ＳＥＭ研究结果表明聚苯乙烯与一种热致液晶聚合物完全不相容。共混体系具有与组分无关的Ｔｇ，并且表现出明显的两相结构。将ＰＳ进行化学改性，随中和盐离子的变化有；酸式，Ｌｉ，Ｎａ，Ｚｎ和Ｍｎ盐五种形式。用ＤＳＣ和ＳＥＭ对ＬＣＰ与ＳＰＳ共混物的热性能和形态进行了分析和表征。     

PET／PA66／液晶共聚酯酰胺共混体系的流变性能

采用ＳＥＭ１、热偏光显微研究了聚对苯二甲乙二酯（ＰＥＴ）／聚酰胺６６（ＰＡ６６）／热致液晶共聚酯酰胺（ＬＣ３０）三元共混物的形态结构;利用Ｉｎｓｔｒｏｎ３２１１型毛细管流变仪研究了共混物的流变性能,结果表明：ＰＥＴ／ＰＡ６６／ＬＣ３０共混物为一热力学不相容的多相聚合物体系,ＬＣ３０的加入提高了ＰＥＴ／ＰＡ６６的相容性,有效地改善了ＰＥＴ／ＰＡ６６共混物的流变性能,ＰＥＴ／ＰＡ６６／ＬＣ３０三元共混     

引入离子基团改善聚苯乙烯与热致液晶聚合物的相窝性：Ⅱ.用FTIR研究分子间

向聚苯乙烯中引入磺酸基团可以有效地改善ＰＳ与一种热致液晶聚合物之间的相容性。用溶液共混的方法制备了ＰＳ和磺化聚苯乙烯与ＬＰＣ的共混物。     

醋酸纤维素／聚乙烯基吡咯烷酮共混体系的相容性研究（Ⅰ）

用ＤＳＣ，ＤＭＴＡ研究了醋酸纤维素（ＣＤＡ），聚乙烯基吮咯烷酮（ＰＶＰ）及ＣＤＡ／ＰＶＰ共混体系的玻璃化转变行为．用精密量热法测定了该体系的混合热焓．结果表明：共混体系只存在一个玻璃化转变温度（Ｔｇ），其值随共混组成的变化而改变；共混体系的混合热焓为负值，其绝对值随组成中ＰＶＰ含量的增加而减少．力学性能研究表明，共混体系具有协同效应．上述试验结果证明，ＣＤＡ和ＰＶＰ是一对相容性高聚物．     

PVC/PBD-b-PMMA共混体系相容性的研究

采用ＤＭＡ和ＴＥＭ系统研究了聚丁二烯－聚甲基丙烯酸甲酯的嵌段共聚物（ＰＢＤ－ｂ－ＰＭＭＡ）与聚氯乙烯（ＰＶＣ）共混体系的相容性问题。结果表明：ＰＶＣ／ＰＢＤ－ｂ－ＰＭＭＡ共混体系具有部分相溶性。相容的程度与共混体系的组成、组分聚合物的分子量以及共聚物中ＰＢＤ和ＰＭＭＡ嵌段的比例密切相关。     

Studies on the synthesis and properties of thermotropic liquid crystalline polycarbonates. VII. Liquid crystalline polycarbonates and poly(ester‐carbonate)s derived from various mesogenic groups

Three series of thermotropic liquid crystalline polycarbonates and poly(ester‐carbonate)s were prepared by solution polycondensation of 4,4′‐biphenyldiol (BP), 4′‐hydroxybiphenyl‐4‐hydroxybenzoate (HHB), or 4‐hydroxyphenyl‐4″‐hydroxybiphenyl‐4′‐carboxylate (HHBP), as mesogenic unit, with 1,10‐bis(p‐hydroxybiphenoxy)decane (N10), bisphenol A (BPA), 4,4′‐dihydroxy‐diphenyl ether (BPO), 4,4′‐[phenylbis(oxy)]bisphenol (BPOO), methylhydroquinone (MeHQ), or phenylhydroquinone (PhHQ). One series of cholesteric poly(ester‐carbonate)s were also prepared by using HHBP, the aromatic diols mentioned above and isosorbide as the chiral moiety. All polycondensations were implemented in pyridine by using triphosgene as the condensation agent. The synthesized polycarbonates were characterized by viscometer, FTIR, DSC, TGA measurements, polarizing microscopy equipped with a heating stage, and WAXD powder pattern. In this study, it was found that the liquid crystalline properties of polycarbonates strongly rely on the mesogenic unit applied. HHBP‐series exhibits a wide temperature region of liquid crystalline (LC) phase even with 50% of bisphenol A (BPA), which is a V‐shaped structure and usually destroys liquid crystalline properties. In addition, homopolycarbonate with HHBP structure possesses extraordinarily low phase‐transition temperature and wide liquid crystalline phase range, due to its asymmetric structure. This asymmetric structure results in head‐to‐tail, head‐to‐head, and tail‐to‐tail random conformation of polymer chain. The isosorbide containing poly(ester‐carbonate)s formed cholesteric phase, which showed homogeneous blue, green, or red Grandjean texture upon shearing in molten state and the Grandjean texture could be frozen easily while quenching the sample to the room temperature. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1852–1860, 2000     

Phase Transfer Catalysis in the Polycondensation Processes. XXV. The Relationship Between Structure and Supramolecular Ordering of Some Aromatic Polyethers Containing Flexible Spacer

Abstract

The paper presents a study concerning the influence of the chemical structure on the supramolecular ordering [crystalline, liquid crystalline (LC), or amorphous] of some aromatic polyethers. The polymers were synthesized using a phase transfer catalysis technique, in a liquid/liquid system, starting from 1,4‐dichlorobutane or 1,5‐dichloropentane and various bisphenols, as follows: 4,4′‐dihydroxyazobenzene (DHAB), 4,4′‐dihydroxydiphenyl (DHD), bisphenol A (BPA), and 2,7‐dihydroxynaphtyl (DN). All polymers were characterized by using ¹H‐NMR, DSC, and optical microscopy in polarized light. Some samples containing azobenzene moieties showed LC properties, but the majority of them resulted as semi‐crystalline compounds. If a bent bisphenol was used (BPA) to obtain homopolymers or copolymers, only amorphous products were obtained. The low thermal stability of the LC products generated some difficulties regarding the characterization of the mesophase. Generally, the copolymerization reaction influenced only the crystalline melting points, the isotropization temperature of the LC polymers being situated near their thermal degradation limit.     

Thin-film polymerization and characterization of Sumitomo's Sumikasuper®-type liquid crystalline polymers

Using the thin film polymerization approach, we have studied the texture evolution when synthesizing a novel liquid crystalline polymer (LCP) system based on Sumikasuper^® LCPs. The main monomers used were p-acetoxybenzoic acid (ABA), 4,4′-biphenol (BP), isophthalic acid (IA), phthalic acid (PA) and terephthalic acid (TA). Polarizing optical microscopy (POM), FTIR, X-ray diffraction (XRD) and atomic force microscopy (AFM) were employed to study the thin film polymerization process and characterize the products. The generation and evolution of liquid crystal phases were monitored; the results revealed that there exists a composition range for the monomers to react and form liquid crystal materials. The critical temperature for LC formation in ABA/BP/IA system decreased with increasing ABA content. FTIR results confirmed the formation of polymers. AFM investigation suggested a similar process of morphological change to that observed using POM. An increasing surface roughness of the thin films with the progress of polymerization was also obtained from AFM analysis. A nematic LC texture of the polymer system was suggested by XRD examination. Results obtained by replacing BP with acetylated BP, and by conducting polymerization using two-monomer systems, suggest that BP units are included in polymers obtained by the thin film polymerization method.     

Thin-film polymerization and characterization of Sumitomo's Sumikasuper®-type liquid crystalline polymers

Using the thin film polymerization approach, we have studied the texture evolution when synthesizing a novel liquid crystalline polymer (LCP) system based on Sumikasuper^® LCPs. The main monomers used were p-acetoxybenzoic acid (ABA), 4,4'-biphenol (BP), isophthalic acid (IA), phthalic acid (PA) and terephthalic acid (TA). Polarizing optical microscopy (POM), FTIR, X-ray diffraction (XRD) and atomic force microscopy (AFM) were employed to study the thin film polymerization process and characterize the products. The generation and evolution of liquid crystal phases were monitored; the results revealed that there exists a composition range for the monomers to react and form liquid crystal materials. The critical temperature for LC formation in ABA/BP/IA system decreased with increasing ABA content. FTIR results confirmed the formation of polymers. AFM investigation suggested a similar process of morphological change to that observed using POM. An increasing surface roughness of the thin films with the progress of polymerization was also obtained from AFM analysis. A nematic LC texture of the polymer system was suggested by XRD examination. Results obtained by replacing BP with acetylated BP, and by conducting polymerization using two-monomer systems, suggest that BP units are included in polymers obtained by the thin film polymerization method.     

原位复合材料的加工性能

使用ＨＢＩＲｈｅｏｍｉｘ６１０型混合机将四种全芳香族热致液晶聚合物与热塑性树脂熔融共混，研究了混合效果，混合过程的平衡转矩与时间，温度的关系，结果显示，用该混合机可以得到均匀分散的共混体系，这些液晶聚合物具有大大低于纯聚砜的熔体粘度，将其与聚砜熔混，可使其混体系的平衡转矩比纯聚砜减小２－３倍，说明液晶聚合物是一种加工助剂，能用来改善高性能工程塑料的加工性能。     

Synthesis and characterization of main chain liquid crystalline ionomers containing sulphonate groups

A series of main chain liquid crystalline ionomers containing sulphonate groups pendent to the polymer backbone were synthesized by an interfacial condensation reaction of 4,4′‐bis(1,10‐sebacyloxo)benzoic acid, brilliant yellow (BY), and 4,4′‐biphenyldiol. 4,4′‐Bis(1,10‐sebacyloxo)benzoic acid exhibited nematic schlieren texture during heating and cooling. The ionomers are thermotropic liquid crystalline polymers and thermally stable to about 270°C. They exhibit broad mesophase regions over a range of 220°C and the same nematic mesomogen with a colourful thread texture as B₀‐LCP, which implies that the introduction of an ionic group did not change the texture of the B₀‐LCP. However, the thermotropic liquid crystalline properties were somewhat weakened when the concentration of BY was more than 5%. The inherent viscosity in N,N‐dimethylformamide solution suggested that intermolecular associations of sulphonate groups occurred at low concentration, and intermolecular associations predominated at higher concentration.     

Functional polymers and sequential copolymers by phase-transfer catalysis. 15. Thermotropic copolyethers based on 4,4′-dihydroxybiphenyl,bisphenol a and 1,9-dibromononane

Thermotropic liquid crystalline (LC) copolyethers have been synthesized from 1,9-dibromononane, a nonmesogenic bisphenol (4,4′-isopropylidenediphenol [BPA]) and a mesogenic bisphenol (4,4′-dihydroxybiphenyl [HB]) by a two-phase (organic solvent—aqueous NaOH) phase-transfer catalyzed polyetherification. LC polyethers were obtained for copolymers containing as much as 70 mol % BPA. Optical polarizing microscopy and DSC have revealed smectic mesomorphism for all the copolyethers. The influence of both copolymer composition and microstructural changes, including the nature of the chain ends, upon the mesomorphic properties of these copolyethers have been discussed.     

Pyrolysis – capillary gas chromatography combined with on-line alkylation for the compositional analysis of liquid crystalline aromatic polyesters

Pyrolysis–capillary gas chromatography combined with on-line alkylation has been employed for compositional analysis of liquid crystalline aromatic polyesters (LCPs) based on p- hydroxybenzoic acid. The fundamental conditions were examined using an LCP prepared from p-hydroxybenzoic acid, terephthalic acid, and 4,4′-biphenol and every constituent of a sample weighing ca. 50 μg was almost quantitatively recovered as its dimethyl derivative in the pyrogram obtained following pyrolysis at 400°C in the presence of 1 μl of 25% tetramethyl-ammonium hydroxide in methanol. The compositions of a variety of terpolyesters and LCPs containing isophthalic acid or 2-hydroxy-6-naphthoic acid units have been precisely deter-mined by pyrolysis-methylation GC.     

含液晶聚合物的原位复合材料中界面相容性的改善策略

综述了近年来含液晶聚合物的原位复合材料中增容技术的一些进展,主要了四种增容技术,即加入具有增容作用的第三组分;在分散相液晶聚合物的主链上引入与基体树脂主链中相同或相似的单元,酯交换反应和多元共混技术,简要描术字原位复合材料的发展趋势。