液晶离聚物的合成及其原位复合纤维形态研究

以ＰＥＴ、ＰＥＴ磺酸型离聚物（ＳＰＥＴ）和对乙酰氧基苯甲酸（ＰＡＢＡ）为原料合成了一系列共聚酯离聚物,经表征表明产物是热致液晶聚合物（ＴＬＣＰ）。不同离子含量的液晶离聚物与不同极性的热塑性聚合物基体共混纺丝得到原位复合纤维,经形态分析表明,液晶离聚物分子中的离子和基体分子中的偶极之间的相互作用改善了两相间的相容性,使液晶分散相分布均匀且形成长径比更大的微纤;离子含量越高,其体极性越强,这种效应越明显;但微纤细到一定程度时容易破裂而使分散相成球粒状分布,影响增强效果。     

含不同离子的液晶离聚物对PBT/PP共混物的形态结构和力学性能的影响

合成了三种含有不同离子的液晶离聚物:含磺酸离子的液晶离聚物(LCI-S),含铵离子的液晶离聚物(LCI-N)和含有羧酸离子的液晶离聚物(LCI-C),将三种液晶离聚物分别与聚对苯二甲酸丁二醇酯(PBT)和聚丙烯(PP)熔融共混。将合成的共混物通过三维红外图象系统和拉伸试验方法进行了微观形态和力学性能的分析。比较不同离子对共混物相容性的影响。结果表明,由于磺酸离子的极性铵离子羧酸离子,因此LCI-S对共混物的增容作用LCI-NLCI-C。     

溶液法合成Na、Zn、Al、La离聚物的研究

用溶液法合成了低密度聚乙烯接枝马来酸钠,马来酸锌、马来酸铝、、马来酸镧离聚物。产物ＩＲ谱表明,所有的离聚物都会出现羧酸盐的吸收峰;ＷＡＸＤ衍射结果则说明,所有的离聚物都显示了离子峰。高聚物的微晶尺寸存在以下顺序：Ｎａ离聚物〉Ａｌ离聚物〉Ｌａ离聚物〉Ｚｎ离聚物,ＤＣＳ的结果表明离子微区的稳定性为Ｚｎ＾２＋〉Ｎａ＾＋〉Ａｌ＾３＋〉Ｌａ＾３＋。     

磺酸基遥爪液晶离聚物的合成与表征

采用溶液缩聚法将活性端基为TPC的液晶聚合物与对羟基偶氮苯磺酸反应制得端基为磺酸基的遥爪主链液晶离聚物.利用红外光谱分析对其结构进行了表征,采用偏光显微镜、示差扫描量热仪和广角X射线衍射等手段对其液晶性能进行了表征.结果表明:各离聚物与原没有加入离子单体的聚合物具有相同的织构,均为向列型液晶.对于同一链段长度的聚合物,当引入离子单体的含量增加时,液晶性逐渐消失;各液晶离聚物的介晶转变温度Tc和熔点Tm随着离子加入量的增加略有增加,但Tg降低.     

侧链含偶氮基的聚硅氧烷类液晶高分子及其离聚物的合成与表征

以4－烯丙氧基－4’－硝基偶氮苯（M1）和4－烯丙氧基苯甲酸（M2）为单体，通过与聚硅氧烷接枝聚合，合成了一系列聚合物PI－PⅣ及离聚物PV－PⅧ。合成的液晶单体、聚合物及离聚物的结构均通过红外或核磁的验证，并通过DSC、偏光显微镜和X射线衍射研究了其液晶行为，聚合物PI－PⅣ及离聚物PV－PⅧ为向列型液晶。液晶基元的含量和离子 基元的引入对液晶的玻璃化温度（Tg）、液晶相范围（△T）等有显著的影响。聚合物PI-PⅣ随着液晶基元含量的增加，其Tg从98．8℃降低到61．9℃，相应地△T从19．8℃拓宽到43．6℃；离聚物PV－PⅧ的液晶行为随着离子含量的增加，其清亮点（Tc)从166．2℃降低于134.5℃，△T也相应地缩短，当离子含量达到40％时，离聚物的液晶相消失。     

聚氨酯离聚物固体电解质的低频介电特性

测定了聚氨酯离聚物固体电解质的交流阻抗谱，分析了离子导体电导率的温度依赖性和低频介电特性。结果表明，聚氨酯离聚物固体电解质具有较高的离子电导率，电导率的温度依赖性不服从Ａｒｒｈｅｎｉｕｓ型方程，而服从经验的ＶＴＦ方程。离子导体表现出非Ｄｅｂｙｅ型介电行为，具有与无机固体电解质相似的低频介电特性。     

离聚物对PET／LDPE共混物的结构与性能研究

用双螺杆挤出机反应性挤出的方法合成了低密度聚乙烯接枝马来酸镧（ＬＤＰＥ－ｇ－ＭＡＬａ）离聚物。与其它方法相比，该法具有工艺简单，易于工业化生产的特点。我们将离聚物与ＰＥＴ，ＬＤＰＥ在双螺杆挤出机上熔融共混挤出，并用注射成型机制备标准样条，对共混物力学性能进行了测试，发现离聚物有显著的增韧效果，另外，通过ＩＲ，ＤＳＣ，溶解性实验，分子量的测定等还考察了离聚物对ＰＥＴ／ＬＤＰＥ共混体系的结构影响。     

SPS及其离聚体的形态结构与热性能

通过ＤＳＣ、ＤＭＡ、ＴＥＭ、ＳＡＸＳ和ＴＧ对ＳＰＳ（磺化聚苯乙烯）及其离聚体的形态结构和热性能进行了研究。结果表明，在磺酸基含量为９．８３ｍｏｌ％的ＳＰＳ中有磺酸离子的聚集。金属离子的引入使ＳＰＳ离聚体的分子间作用力、微相分离程度增大。磺酸盐含量为４．７０ｍｏｌ％以上的ＳＰＳ离聚体中有离子聚集，离子簇直径为３～１０ｎｍ。在磺酸盐含量为１３ｍｏｌ％范围内，ＳＰＳＮａ离聚体基体的Ｔｇ１、离子微区的Ｔｇ２均随磺酸盐含量的增加而线性增大。ＰＳ磺化、中和成ＳＰＳ离聚体后，热稳定性增加，其顺序为：ＳＰＳＺｎ＞ＳＰＳＮａ＞ＳＰＳ＞ＰＳ。     

聚体Surlyn对PET/PA-6共混物的相容性及形态结构的影响

通过偏光显微镜观察,扫描电镜观察,动态力学分析和广角和Ｘ射线衍射分析,研究了离聚物Ｓｕｒｌｙｎ对ＰＥＴ／ＰＡ－６共浊 相容性及形态结构的影响。     

羧酸侧基对主链液晶聚合物性能的影响

采用溶液缩聚的方法,以4,4′-对羟基联苯(MB)、2,5-二羟基苯甲酸(MC)、癸二酰氯(SD)为单体,合成了主链液晶离聚物。通过红外光谱(FT-IR)、偏光显微镜(POM)、差示扫描量热(DSC)、X射线衍射(XRD)等手段研究了离子单体对主链液晶离聚物性能的影响。结果表明,所合成的聚合物都为热致近晶型液晶聚合物。其Tg,Tm和Ti随离子含量的增加呈现不同的变化趋势,少量的2,5-二羟基苯甲酸钠(MC-Na)增宽了聚合物的液晶区间,但较大量的MC-Na破坏了液晶相。     

Synthesis,structure, and mesomorphic properties of main-chain liquid-crystalline ionomers containing sulfonate groups

The mesogenic monomer M and a series of main-chain liquid crystalline ionomers (LCIs) containing sulfonate groups were synthesized. The LCIs were prepared by an interfacial condensation reaction of mesogenic monomer 1,4-phenylene-dicarbonic acid bis (4-carboxyl phenyl) ester, brittle yellow (BY), 1,10-sebacoyl dihydroxy, and 1,12-dodecanedioyl dihydroxy. The sulfonate groups introduced to the main-chain backbone were confirmed by ultraviolet spectroscopy. The mesomorphic properties were investigated by differential scanning calorimetry (DSC), thermo gravimetric (TG), and polarizing optical microscopy (POM). Experimental results demonstrated that the glass-transition temperatures increased slightly, melting temperature decreased, and the mesophase temperature ranges increased first and then decreased with increasing content of sulfonate group. All of the polymers were thermally stable up to 320 °C. The LCI _n s exhibited typical nematic schlieren textures.     

Influence of the polymer backbone structure on the properties of aromatic ionomers with pendant sulfobenzoyl side chains for use as proton-exchange membranes

Six different ionomers having various aromatic polymer backbones with pendant 2-sulfobenzoyl side chains were prepared by nucleophilic aromatic substitution reactions of lithium 2,6-difluoro-2'-sulfobenzophenone with 4,4-biphenol, 2,7-dihydroxynaphthalene, 4,4-isopropylidenediphenol, 4,4-dihydroxydiphenyl ether, 4,4'-thiodiphenol, and 4,4'-thiobisbenzenethiol, respectively, to produce four poly(arylene ether)s, one poly(arylene ether sulfide), and one poly(arylene sulfide). Mechanically tough proton-exchange membranes with ion-exchange capacities in the narrow range from 1.9 to 2.3 mequiv/g were cast from the high-molecular-weight ionomers, and subsequently investigated with respect to their structure-property relationships. Glass transitions were only detected for ionomers in the sodium salt form, and increasing glass-transition temperatures (Tg) were found to give higher thermal decomposition temperatures. Analysis by small-angle X-ray scattering indicated that the ionic clustering was promoted for ionomers with flexible polymer backbones and low Tg values. The proton conductivity of the membranes at 80 °C under fully humidified conditions was found between 0.02 and 0.2 S/cm and appeared to depend primarily on the Tg.     

芳香族聚噻唑的结构与物理性能的研究

以二氨基二苯醚及二氨二苯甲烷为原料,通过一系列有机合成反应,制备出单体4,4′-二氨基-3,3′-二巯基二苯醚二氯化氢和4,4′-二氨基-3,3′-二巯基二苯甲烷二氯化氢。以多聚磷酸为溶剂,与对苯二甲酸、邻苯二甲酸和间苯二甲酸溶液聚合,合成四种不同的芳香族聚噻唑聚合物。通过对聚合物的耐热性能、结晶性能以及液晶行为的研究比较,发现四种聚合物都是耐热性较好的材料,但由于结构不同,它们的耐热性能、结晶性以及液晶行为有所不同。     

Thermoplastic elastomers based on ionomeric polyblends of zinc salts of poly(propylene-co-acrylic acid) and carboxylated nitrile rubber

Ionomeric polyblends of zinc salt of carboxylated nitrile rubber, abbreviated as Zn-XNBR and zinc salt of poly(propylene-co-acrylic acid), abbreviated as Zn-PPA, were prepared by melt blending. The ionomeric polyblends of Zn-XNBR/Zn-PPA in the compositions of 90/10 and 80/20, parts by weight, behave as ionic thermoplastic elastomers and exhibit synergism in properties. The ionomeric polyblend shows superior physical properties than the corresponding non-ionomeric polyblend. The synergism and superior physical properties of the ionomeric polyblends are attributed to the formation of strong intermolecular ionic interactions between the component polymers, as observed by the infrared spectroscopic studies. Dynamic mechanical thermal analyses reveal that besides glass-rubber transition in the low temperature region, the neat ionomers and the ionomeric polyblends show a high temperature transition owing to the relaxation of the restricted mobility chain segments in the ionic cluster region. The reprocessability studies reveal the thermoplastic elastomeric nature of the ionomeric polyblend.     

羧基遥爪热致性主链液晶离聚物的合成与表征

以对羟基苯甲酸甲酯和1,4-丁二醇为主要原料,经熔融酯交换合成介晶基元双(对羟基苯甲酸)丁二醇酯(BBHB);以四氯乙烷为溶剂,采用溶液缩聚法将BBHB与适量的对苯二甲酰氯(TPC)反应,经Na2CO3溶液处理,合成端基为羧基的液晶离聚物。通过红外光谱等分析对它们的化学结构进行了表征。表明:所合成的液晶离聚物P1~P3为纹影织构,属于典型的向列型液晶,液晶相区间为100℃左右,羧基对液晶区间和玻璃化转变温度(Tg)、熔融温度(Tm)、相转变温度(Tc)影响不大。     

Photo-switching and nonlinear optical behaviors of center linked bent-core azobenzene liquid crystalline polymers

A new class of two series (I and II) of center linked bent-core azobenzene liquid crystalline polymers were prepared. They were prepared from two different spacer lengths (2 and 10) between polymer backbone and bent-core mesogen. The bent-core mesogen possesses photoactive linking group with variable terminal chains (7, 8, and 9). The synthesized precursors, monomers, and polymers were characterized by FT-IR, ¹H NMR, and ¹³C NMR spectroscopy. Thermal stability of polymers was examined by thermogravimetric analysis. The mesophase transition of monomers and polymers were observed through polarized optical microscopy, and confirmed by differential scanning calorimetry. Among the two series of polymers, the second series of polymers possesses liquid crystalline properties. The photo-switching properties of bent-core azo polymers were investigated using UV–Vis spectroscopy, trans to cis isomerization occurs around 35 s in chloroform and 65 s in thin film, where as reverse processes take place almost 32 h in chloroform. The photo-switching processes of polymer IIa precedes faster and also longer time thermally stable when compared with recently reported similar polymers. Negative optical nonlinear refractive index and optical limiting properties of the polymers were measured using Nd-YAG laser.     

Electroactive Thermoplastics

Proton‐exchange membrane fuel cells are one of the most commercially important applications of electroactive polymers. It has been found that their performance can be optimized by controlling water transport via thin layers of ionomers with increasing equivalent weights in the catalyst layer (see Figure). Recent developments in this area are presented here within the context of development of innovative electroactive materials.     

热致性液晶氯代聚芳酯的合成与表征

以２，５－二氯对苯二甲酰氯，ｏ－、ｍ－、ｐ－苯二酚，２，７－，２，６－，１，５－，１，６－萘二酚，１，６－己二醇为单体，溶液缩聚得到了３个系列１２种热致性液晶氯代聚芳酯，采用红外光谱（ＩＲ）、ＤＳＣ／ＴＧ、Ｘ衍射、热台偏光显微镜、扫描电镜（ＳＥＭ）等对所获得的聚合物结构、液晶性、耐热性、结晶性、表观形态、溶解性进行了表征分析。较详细地探讨了热致性液晶聚芳酯侧基取代和柔性链段等不同结构与性能之间的关