芳香─脂肪族共聚酰胺的序列结构和溶致液晶性能

本文利用对苯二甲酰氯（ＴＰＣ），对苯二胺（ＰＰＤ）和亚甲基数为２和６的两种脂肪族二无胺（ＡＤＡ）合成了具有不同序列结构的芳香－脂肪族共聚酰胺。研究了共了聚酰胺的序列结构参数－无规度Ｂ和数均序列长度Ｌｎ与液晶临界浓度Ｃ＊和中介相的类型之间的关系。     

缩聚的溶剂体系对芳香－脂肪族共聚酰胺序列结构的影响

本文研究了以对苯二甲酰氯、对苯二胺和乙二胺三元共缩聚物为代表的芳－脂族共聚酰胺低温溶液缩聚中的溶剂、助溶剂（盐）和酸吸收剂等对共聚酰胺链序列结构参数－无规度（Ｂ）和数均序列长度（Ｌ）－的影响．     

缩聚的溶剂体系对芳香－脂肪族共聚酰胺序列结构的影响

本文研究了以对苯二甲酰氯，对苯二胺和己二胺三元共缩聚物为代表 的芳－脂族共聚酰胺低温溶液缩聚中的溶剂、助溶剂（盐）和酸吸收剂等对共聚酰胺链序列结构参数－无规度（Ｂ）和数均序列长度（Ｌｎ）的影响。     

脂肪族聚酯-酰胺的研究进展

脂肪族聚酯-酰胺（polyester-amides）合了聚酯和聚酰胺的优点,如具有优良的物理力学性能和加工性能等等。因此,对脂肪族聚酯-酰胺的研究成为近年来的研究热点。本文从脂肪族聚酯-酰胺的模型化合物（以双酰胺-二醇单体为例）的研究进展入手,分析了模型化合物的结构特点,以及模型化合物与相应聚合物之间的联系,从而为进一步研究聚合物打下一定的基础。本文还综述了脂肪族聚酯-酰胺的分类,各类脂肪族聚酯-酰胺的合成方法,以及脂肪族聚酯一酰胺在可生物降解材料和热塑性弹性体等领域的应用。     

芳香-脂肪族共聚酰胺溶致液晶行为的研究

本文对脂肪族二元胺(ADA、NH_2(CH_2)_nNH_2、n=2、6、8、10、12),对苯二胺(PPD)和对苯二甲酰氯(TPC)三元芳香-脂肪族共聚酰胺硫酸溶液的溶致液晶性能进行了研究.利用偏光显微镜、小角和宽角X-光衍射确定了该类共聚酰胺溶致液晶中介相的类型随共聚物中脂肪族二胺链单元含量的变化规律.     

聚(丙烯酰胺-丙烯酸)/聚(丙烯酰胺-二甲基二烯丙基氯化铵)聚电解质复合溶液动态光散射研究

通过动态光散射、粘度和透光率测定，研究了聚（丙烯酰胺 丙烯酸）［Ｐ（ＡＭ ＡＡ）］／聚（丙烯酰胺 二甲基二烯丙基氯化铵）［Ｐ（ＡＭ ＤＭＤＡＡＣ）］聚电解质复合溶液的结构和性能．结果表明，Ｐ（ＡＭ ＡＡ）与Ｐ（ＡＭ ＤＭＤＡＡＣ）复合比、溶液浓度和氯化钠用量影响溶液中复合物的构象和流体力学半径．Ｐ（ＡＭ ＡＡ）与Ｐ（ＡＭ ＤＭＤＡＡＣ）分子链间适度的库仑相互作用，可形成均相Ｐ（ＡＭ ＡＡ）／Ｐ（ＡＭ ＤＭＤＡＡＣ）聚电解质复合溶液，复合物具有较伸展的构象和较大的流体力学半径，因而溶液粘度较高．Ｐ（ＡＭ ＡＡ）与Ｐ（ＡＭ ＤＭＤＡＡＣ）分子链间过强的库仑相互作用或小分子电解质的屏蔽作用，可使复合物构象卷曲，结构紧缩，流体力学半径减小，甚至产生相分离，导致溶液粘度降低．     

全芳共聚酰胺序列结构的计算及其溶致液晶行为

从芳香二酰氯与芳香二胺反应本质入手，解决了各种加料方式得到的全对位、全芳香共聚酰胺的序列结构问题．提出一个较为直观的模型，并用此模型很好地解释了共聚酰胺浓硫酸溶致液晶行为受序列结构影响的原因．揭示液晶行为与序列结构之间的关系     

酯－酰胺交换反应对聚对苯二甲酸乙二酯／聚酰胺66共混体形态结构和流变性能的影响

采用不同的共混方式－溶液法、熔融法Ⅰ（简单机械共混）和熔融法Ⅱ（存在酯－酰胺交换反应）将聚对苯二甲酸乙二酯（ＰＥＴ）与聚酰胺６６（ＰＡ６６）共混，研究了共混体的形态结构和流变性能，探讨了对甲苯磺酸（ＴｓＯＨ）催化下的酯－酰胺交换反应和ＰＥＴ／ＰＡ６６共混体系的相容性．     

高效高分子酰化催化剂——含超亲核试剂聚酰胺的合成与表征

以４ 氨基吡啶为原料,制备各种含烷氨基吡啶基团的二元酰氯和二元胺反应性单体,再经缩聚反应得到聚酰胺型高分子超亲核催化剂．用气相色谱跟踪以聚酰胺催化的叔丁醇反应,结果表明,聚酰胺在酰化反应体系中有着良好的溶解性,含烷氨基吡啶基团的线型聚酰胺具有比４ （ Ｎ,Ｎ 二甲基氨基） 吡啶（ＤＭＡＰ） 更高的催化能力,而交联型树脂较其线型聚合物活性有所降低．     

吡啶－2，6－二甲酸钪配合物［Sc（HDPA）（DPA）（H_2O）_2］·5

在水溶液中合成了吡啶－２，６－二甲酸抗配合物的晶体，元素分析结果表明，可用Ｓｃ（ＨＤＰＡ）（ＤＰＡ）·７Ｈ＿２Ｏ表示，用Ｘ射线衍射方法测定了配合物的单晶结构，其结构式为［Ｓｃ（ＨＤＰＡ）（ＤＰＡ）（Ｈ２Ｏ）２］·５Ｈ２Ｏ。晶体属正交晶系，空间群为Ｐｎ２１ａ。晶胞参数如下：ａ＝１．０１６９（２）ｎｍ，ｂ＝１．０１７２（２）ｎｍ，ｃ＝２．０２５４（４）ｎｍ；Ｖ＝２．０９５（１）ｎｍ３，Ｚ＝４，Ｄ＝１．５９ｇ／ｃｍ３。抗离子的配位数为８，其配位多面体为三角十二面体。     

ODD-EVEN EFFECT OF LYOTROPIC LIQUID CRYSTALLINE PROPERTIES OF AROMATIC-ALIPHATIC COPOLYAMIDES

 A series of aromatic-aliphatic copolyamides containing different aliphatic diamine units was synthesized by low temperature solution polycondensation. The liquid crystalline critical concentration (c^*) and liquid crystalline critical temperature (T^*) of these copolyamides exhibited an odd-even zigzag effect with the odd-even variation of carbon atom number in the aliphatic dimes used.     

The DSC Study of PA 6, Polyamides and Copolyamides

The DSC method was used to obtain more information on changes of thermal properties connected with different comonomers bound in the (co)polymer chains. The copolyamides propered were block ones which were less crystalline and compatible with poly-ε-caprolactam. The results have confirmed the crystalline nature of polyamides and copolyamides. This revised version was published online in August 2006 with corrections to the Cover Date.     

含二氮杂萘酮结构溶致液晶聚芳酰胺的合成及性能

以Kevlar(R)(其结构为聚对苯二甲酰对苯二胺,PPTA)为代表的聚芳酰胺,分子链排列非常规整,分子键具有很强的极性和分子间氢键作用,这一结构特点赋予它们良好的热稳定性,优秀的耐化学性能,独特的溶致液晶性和优异的机械性能.但是另一方面也造成了它们在常用有机溶剂中有限的溶解性和高的熔融温度,因而限制了它们的生产和应用[1～3].     

Sequence distribution of repeating units of copolyamides by interfacial or solution methods

The sequence distribution of repeating units of copolyamides from different diamines with isophthaloyl or terephthaloyl chlorides and dithiophenyl adipate have been investigated either by interfacial or solution methods to aim at the sequence control of the copolyamides by solvents. Copolycondensation of dithiophenyl adipate and isophthaloyl chloride with m-xylylenediamine in various solvents yielded copolyamides having different compositions of repeating units. Aprotic polar solvents produced random copolyamides having the same compositions as feed ratios of the comonomers, while nonpolar solvents yielded copolyamides rich in isophthaloyl units. Also the sequence distribution of the copolyamides from m- and p-phenylenediamines with isophthaloyl chloride was affected by solvents; nonpolar solvents produced copolyamides having a less-random and block character of the repeating units either by interfacial or solution methods.     

Synthesis and characterization of glycine copolymers of nylons 6 and 12

Copolymers of glycine and 6-aminohexanoic or 12-aminododecanoic acid within a range of molar compositions from 80/20 to 5/95 were prepared by solution polycondensation of the adequate proportion of the respective pentachlorophenyl ester hydrobromides. Despite their random composition, the copolymers obtained were found to be highly crystalline. Intrinsic viscosities of 2/6 and 2/12 copolyamides were similar and rather low (M_n, ca. 3000-5000). Thermal post-polycondensation allowed to increase the molecular weight of 2/12 copolyamides, so that fibers could be prepared. The composition and sequence distributions were evaluated by means of ¹H- and ¹³C-NMR spectroscopies. Copolyamides were also characterized in terms of thermal properties. Melting and glass transition temperatures are reported. Crystallinity was evaluated from heats of fusion. Crystalline structure was examined by infrared spectroscopy and wide-angle x-ray diffraction. The presence of structures related to the polyglycine I and to α/γ-nylons was confirmed depending on the molar composition. Highly oriented fibers with good tensile properties were obtained from the nylon 2/12 (10 : 90) copolymer. © 1995 John Wiley & Sons, Inc.     

Aromatic rigid chain copolymers. I. Synthesis,structure, and solubility of phenyl-substituted para-linked aromatic random copolyamides

Four 2,5-biphenylene based difunctional condensation monomers, such as 2,5-diphenyldicar-boxylic acid or phenylterephthalic acid (PTA), 2,5-bis(carbonylimino-4-benzoic acid)biphenyl (2,5-BCIBABP), 2,5-diaminobiphenyl hydrochloride (2,5-DABP.HCl) and 2,5-bis(iminocarbonyl-4-benzoic acid)biphenyl (2,5-BICBABP), have been synthesized and characterized. These monomers were polymerized in combination with terephthalic acid (TA) and p-phenylenediamine (PPD) via the phosphorylation reaction to prepare a series of phenyl-substituted random copolyamides having all amide groups attached to para-positions of the benzene rings. All the copolyamides have been characterized by solubility, solution viscosity, and by differential scanning calorimetry (DSC). Some of these copolyamides have unusual solubility in organic solvents such as N,N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidinone (NMP) containing dissolved lithium chloride. A few copolyamides were tested for lyotropic behavior and found to form anisotropic solutions at critical concentrations in organic solvents. A randomly distributed unsymmetrical phenyl substituent on the benzene ring of para-oriented wholly aromatic polyamides dramatically changes the solubility and melting point. The phenyl substituent on a terephthalic acid unit is more efficient in decreasing melting point and increasing solubility in organic solvents of aromatic polyamides than the one on a p-phenylenediamine unit. However, the former also introduces a more flexible link in the extended polyamide chain.     

Comparative analysis of structure and temperature behaviour of two copolyamides - regular KEVLAR and statistical ARMOS

In the present investigation X-ray diffraction techniques, DSC and dynamic mechanical relaxation (DMR) methods have been employed to compare the structure and thermal behaviour of Kevlar (“DuPont”, USA) and Armos (Russia) fibers. Our recent studies have indicated that the non-crystalline phase of copolyesters always contains LC smectic structure in addition to some part of the nematic LC mesophase. It turned out that the copolyamides also possess this interesting feature. Moreover, on heating of a semicrystalline copolyester always the second order phase transition from the crystalline state to condis mesophase has been observed, whereas in the case of copolyamides such a transition has the «virtual» character. As was established by other authors both polymers under study reveal the moisture content. The changes in wide angle X-ray scattering of copolyamides under heat treatment were interpreted in terms of desorption of bound water and structural rearrangement in the plane perpendicular to the chain axis involving of the hydrogen bonding between neighboring macromolecules.     

Gas permeability and selectivity of hexafluoroisopropylidene aromatic isophthalic copolyamides

The synthesis, thermal, and gas transport properties of poly(hexafluoroisopropylidene isophthalamide), HFA/ISO homopolymer, and HFA/TERT‐co‐HFA/ISO copolyamides with different poly(hexafluoroisopropilydene‐5‐t‐butylisophthalamide), HFA/TERT, ratios are reported. The results indicate that the glass transition temperatures of the copolyamides increase as the concentration of HFA/TERT in the polyamide increases. The gas permeability coefficients in the polyamides and copolyamides are independent of pressure or decrease slightly particularly with CO₂, N₂, and CH₄. It was seen that HFA/TERT is 2–6 times more permeable than HFA/ISO, depending on the gas being considered. This was assigned to the presence of the bulky lateral substituent, t‐butyl group in HFA/TERT and HFA/TERT‐co‐HFA/ISO copolyamides. This substituent increases fractional free‐volume, as expected. Therefore, the gas permeability and diffusion coefficients generally increase with increasing fractional free‐volume. The experimental results for the gas permeability and permselectivity for the copolyamides was well represented by a logarithmic mixing rule of the homopolyamides permeability coefficients and their volume fraction. The selectivity of gas pairs, such as O₂/N₂, CO₂/CH₄, and N₂/CH₄ decreased slightly with the addition of HFA/TERT. The temperature dependence of permeability for homopolyamides and copolyamides can be described by an Arrhenius type equation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2625–2638, 2005