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的两种脂肪族二元胺（ＡＤＡ）合成了具有不同序列结构的芳香一脂肪族共聚酰胺．研究了共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．     

Synthesis of intrinsically flame‐retardant copolyamides and their employment in PA6‐fibers

Flame‐retarded polyamide 6.6 (FR‐PA6.6) was prepared by the cocondensation of hexamethylene diammonium adipate (AH‐salt) with the corresponding salts of hexamethylene diamine and two different organophosphorus compounds, namely, 3‐hydroxyphenylphosphinylpropanoic acid (3‐HPP, 1) and 9,10‐dihydro‐10‐[2,3‐di (hydroxycarbonylpropyl]‐10‐phosphaphenanthrene‐10‐oxide (DDP, 2). The incorporation of the phosphorus comonomers and the thermal and physical properties of the resulting copolyamides have been studied. The phosphorus‐modified FR‐PA6.6 possesses high relative viscosities of 2.0 to 2.4, good thermal stability, and was used for the production of polyamide blends by merging FR‐PA6.6 with commercial PA6. This offered access to flame‐retarded PA6 multifilaments, which possess tensile strengths up to 0.7 GPa and elastic moduli up to 6.2 GPa. Knitted fabrics of FR‐PA6 exhibit high limiting oxygen index (LOI) values between 36 and 38 and executed burning tests demonstrate that the incorporation of phosphorus‐based comonomers improve flame retardancy significantly. The approach presented here offers a straightforward access to effective flame retardancy in nylon 6.     

Preparation of aromatic copolyamides containing regularly placed 1,6-hexamethylenediamine units

Copolyamides based on poly(m-phenylene isophthalamide) and poly-(p-phenylene terephthalamide), to which 1,6-diaminohexane units were regularly inserted every 3 or 5 phenylene monomer units, were synthesized. The copolymers were obtained by condensation of individually prepared diamino- and dicarboxylic-building blocks via the Yamazaki–;Higashi reaction. Solubility of the copolyamides are discussed in relation with the structure. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2379–2386, 1997     

STUDIES ON THE REGULAR COPOLYMERS OF POLY (1, 4-PHENYLENETEREPHTHALAMIDE)

Two types of the regular copolymer of poly (1, 4-phenyleneterephthalamide) were synthesized by the low temperature solution polycondensation in NMP-CaCl_2 solvent system, using the piperazine or 2,5-dimethylpiperazine as the third components introduced in the main chain of poly (1, 4-phenyleneterephthalamide). The properties of copolymers were characterized by IR, SEM, X-RAY diffraction, polarizing microscopy, TGA and solubilities.Experimental results showed that the copolymers had good solubility and thermal stability, the concentrated sulfuric acid (～98% ) solution of regular PPTA copolymers had liquid crystalline proper-     

LIQUID CRYSTALLINE BEHAVIOR OF AROMATIC COPOLYAMIDE IN CONCENTRATED SULPHURIC ACID

The liquid crystalline behavior of anisotropic solutions in 100% sulphuric acid ofaromatic copolyamide obtained by low-temperature solution copolycondensation of tere-phthalic acid chloride (TPC), p-phenylene diamine (PPD) and 4, 4'-diamino-diphenylether(DAPE) has been studied by optical microscopy and X-ray diffeaction. The effects ofinherent viscosity, concentration of copolyamide in sulphuric acid, the content of the thirdmonomer (DAPE) and sequence distribution of copolyamide on the critical concentration,isotropic temperature, phase diagram and texture of liquid crystal were investigated. Theschlieren texture was observed and the results of X-ray diffraction indicate that the con-centrated solutions of copolyamide exhibit nematic liquid crystalline behavior.     

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.     

Synthesis and characterization of fluorine-containing polyamides derived from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane by direct polycondensation

A fluorine-containing diamine, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (BAPPH) ( II ), was synthesized in two steps on condensation of 2,2-bis(4-hydroxyphenyl)hexafluoropropane with p-chloronitrobenzene in the presence of potassium carbonate, giving 2,2-bis[4-(4-nitrophenoxy)phenyl]hexafluoropropane ( I ), followed by reduction with hydrazine monohydrate/Pd—C. Fluorine-containing polyamides and copolyamides having inherent viscosities 0.41–0.88 dL g⁻¹ were prepared by direct polycondensation of BAPPH with various aromatic diacids or with mixed diacids, by triphenyl phosphite and pyridine in N-methyl-2-pyrrolidinone (NMP). The polyamides were examined by elemental analysis, IR spectra, inherent viscosity, x-ray diffraction, solubility, DSC, and TGA. The diffractogram showed that the polyamides were crystalline except IVb , IVc , IVf , and Vc . Almost all polyamides were soluble in polar aprotic solvents. The polymers obtained from BAPPH lost no mass below 350°C, with 10% loss of mass being recorded above 467°C in nitrogen. These aromatic polyamides had glass transition temperatures in the 221–253°C range. © 1996 John Wiley & Sons, Inc.     

Effects of Blend Ratio on Rheology,Morphology, Mechanical and Oil-Resistant Properties in Chlorinated Polyethylene Rubber and Copolyamide Blends

The elastomeric chlorinated polyethylene (CPE) blended with a low melting point copolyamide (PA6/PA66/PA1010, PA) was prepared by a melt mixing technique. The mixing characteristics of the blends were analyzed from the rheographs. The influence of copolyamide (PA) content on the morphology, mechanical properties, crystallization and oil-resistance, and the addition of compatibilizers on the mechanical properties were also systematically investigated. Morphological examinations clearly revealed a two-phase system in which CPE/PA blends exhibit a cocontinuous morphology for 50/50 composition, and the continuous phase of PA turns into a disperse phase for 70/30, 80/20, and 90/10. There is a distinct interface between the two phases. The mechanical properties, crystallization, and oil-resistance have a strong dependence on the amount of PA. The blends with higher proportions of PA have superior mechanical properties; they are explained on the basis of the morphology of the blend and the cystallinity of PA. In addition, compatibilizers, including chlorinated polyethylene-graft-copolyamide (CPE-G-PA), chlorinated polyethylene-graft-maleic anhydride (CPE-G-MAH), ethylene-n-butyl acrylate-monoxide (EnBACO), and ethylene-n-butyl acrylate-monoxide-graft-maleic anhydride (EnBACO-g-MAH) were added into the blends. Tensile strength and elongation at break go through a maximum value at a compatibilizer resin content (on the basis of the total mass of the blend) of 20 wt% while the PA content is 30 wt%.     

PA-130/CA合金膜材料的研制及其性能

采用溶液共混和液-固相转变法(L-S)制备了用于高效液相色谱(HPLC)柱填料的共聚尼龙/醋酸纤维素共混物(PA-130/CA)。以小分子量化合物为探针分子,用HPLC数据表征了PA-130/CA合金膜材料的界面性能,并研究了其合金膜材料的相容性和热稳定性。结果表明:PA-130与CA有很好的相容性;该合金膜的热稳定性比纯CA膜的有所提高;质量比为30/70的PA-130/CA合金膜对不离解极性有机物的分离效率更高。     

Partially miscible EVOH/copolyamide‐6/6.9 blends: The effect of stretching on the structure

Binary blends of random copolymers, ethylene‐vinyl‐alcohol (EVOH) consisting of 38 mol % ethylene and Copolyamide‐6/6.9 with an approximate 1 : 1 comonomer ratio, were prepared via blown‐film extrusion and uniaxial stretching. The anisotropy induced by the uniaxial deformation of the polymer blends was characterized by X‐ray diffraction and birefringence measurements. The stretched films also were investigated via oxygen permeability. The results showed a sharp decrease in the apparent crystallite size throughout the entire composition range in comparison to the blown films. However, the order perceived within the amorphous phase in the EVOH‐rich blends increased (decrease in oxygen permeability), whereas in the copolyamide‐rich blends, orientation resulted in a decrease in the amorphous phase order (increase in permeability). Apparently, orientation destroyed the amorphous interpolymer complex. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 813–822, 2000