共聚酰胺生产及应用

介绍二元、三元、四元共聚酰胺的共聚反应机理、生产工艺,产品特性和应用,指出共聚酰胺的发展方向。     

锦棉交织物活性染料—浴法染色工艺

分析了锦棉交织物一浴法染色工艺中存在的主要问题,通过选用实验室 研制的助剂CN和合适的活性染料,优化了锦棉交织物活性染料一浴法染色条件。     

用聚丙烯酸酯乳液提高轮胎帘线储存稳定性

研究了一种自交联型五元共聚聚丙烯酸酯乳液的单体种类和配比、加料顺序、表面活性剂的种类和用量、引发剂用量等合成工艺因素与乳液稳定性及其增粘和防紫外线、臭氧老化的关系。用这种乳液改性的ＲＦＬ浸渍液处理锦纶６６轮胎帘线，可以显著改善帘线的储存稳定性。     

Inexpensive synthesis of 1,4-bis(4-aminophenoxy)-2- (6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl) phenylene and its oxygen-plasma resistant polyamides

Inexpensive synthesis of diamine, 1,4-bis(4-nitrophenoxy)-2-(6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl) phenylene was revealed in this work. Based on the diamine, a series of organosoluble polyamides were prepared by direct polycondensation of the diamine with various aromatic diacids using triphenyl phosphite and pyridine as condensing agents. The number-average molecular weights of the resulting polyamides range from 4.2 × 10⁴ to 10.5 × 10⁴ g/mol, and the weight-average molecular weights are in the range of 7.5-28.2 × 10⁴ g/mol. The T_gs of these polyamides range from 210 to 255 °C by dynamic mechanical analysis. The resulting polyamides are tough and flexible with tensile strength, elongation at break and moduli range from 84 to 101 MPa, 4.8-7.0%, and 2.36-3.22 GPa, respectively. The degradation temperatures (T_d 5%) and char yields at 800 °C in nitrogen range from 460 to 486 °C and 59-68 wt%, respectively. The cutoff wavelength of these polyamides falls in the range of 345-366 nm, showing a very light color characteristic. In addition, these polyamides display good oxygen plasma resistance.     

Relations between structure and property of polyamide 11 nanocomposites based on raw clays elaborated by water‐assisted extrusion

Bio‐based polymers and polymer nanocomposites have known an increasing interest during the past few years. This work is focused on the elaboration and the characterization of bio‐based nanocomposites made from polyamide 11 (PA11) and nonorganomodified montmorillonite. To elaborate these materials an original elaboration process, consisting in injecting water during the extrusion, was used. Results show that thanks to this process, a well exfoliated morphology is obtained for clay contents as high as 10% wt. This was explained on the one hand by the fact that the clay is soluble in water and on the other hand by the fact that water and PA11 are miscible at high pressure and high temperature. Moreover, the morphology analyses have revealed that from 10% wt of clay, the platelets were not totally randomly distributed but they were rather organized at a mesoscopic scale. The obtaining of such clay's dispersion involves an enhancement of thermomechanical properties. For example, for a clay content of 10% wt, the Young's modulus of the material can be doubled and its degradation temperature increased. The role of the elaboration conditions on the morphology and subsequent properties of the nanocomposites are also carefully analyzed. Finally, it has been evidenced that the presence of the filler infers on both the crystalline form induced and the crystallization kinetics. In summary, this study demonstrates that, in the case of PA11 nanocomposites, the water‐assisted injection process leads to the achievement of an exfoliated morphology for clay contents as high as 10% wt that allows to obtain high performance materials and to be free from using organomodified clays. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

改性聚酰胺树脂的合成及其在热熔胶领域的应用

以国产低分子聚酰胺树脂为基本原料 ,经过接枝、交联改性 ,在不同合成条件下 ,合成出适应于不同应用场合的三种电性能优异的韧性难燃聚酰胺树脂。该产品可作为热熔粘合剂广泛应用于电子电器、汽车、热缩材料等领域。由于合成中采用来源丰富的国产原料 ,并适量加入废聚酯 ,大大降低了原料成本。测试和应用试验表明 ,产品性能已达到进口同类产品水平。因此该产品具有较大的应用潜力 ,其经济效益和社会效应显而易见     

丝胶改性聚酯和聚酰胺纤维吸放湿性的研究

本文表明用丝胶改性聚酯纤维、聚酰胺纤维以提高改性纤维的吸放湿性是有效的。理论分析与实验结果统一。     

Polyamide hydrolysis accelerated by small weak organic acids

It is well known that acidity, pH, of a solution accelerates the hydrolysis of soluble amides. Here we describe the unexpected result that weak small organic acids at low concentrations hydrolyze a polyamide at rates approximately twice that of a water HCl solution of the same pH. The effect of three small organic acids in dilute solutions, acetic, propanoic, and butanoic was studied. It is observed that the effect on the hydrolysis rate increases as the organic acid gets weaker. Butanoic, the weakest acid, has the strongest effect on increasing the hydrolysis rate. Measurements on the concentration of these acids in the polyamide reveal that there is a selective desire for these weak organic acids to diffuse into the polyamide. The concentration of these acids in the polyamide is found to be several multiples of the concentration in the water environment. And the acid concentration is highest for butanoic. The hydrolysis rate is shown to be governed by solubility, not pH of the water environment. The longer hydrocarbon tail on the carboxylic group increases its compatibility with the polyamide's monomer structure. Results are reported on the hydrolysis of polyamide-11 polymerized from aminoundecanoic acid, both neat and a commercial plasticized composition, placed in water at 100 °C and 120 °C under anaerobic conditions in high pressure glass tubes.     

纳米磷灰石晶体/聚酰胺复合骨组织工程支架材料的研究

采用常压共溶、共沉淀和水热处理的方法制备了纳米磷灰石晶体／聚酰胺复合骨组织工程支架材料。纳米磷灰石在复合材料中含量高达60wt％(重量比),纳米磷灰石和聚酰胺之间有化学键结合,材料的力学性能接近自然骨水平。复合材料可加工成块状多孔体,材料的孔隙率为55％-70％,平均孔径为300μm,多孔支架不仅有大孔,而且大孔壁上含有丰富微孔,是一种非常有发展前景的组织工程材料。     

Structure characterization of heat set and drawn polyamide 66 fibers by FTIR spectroscopy

Structural changes that occur during thermally induced and strain induced crystallization of polyamide 66 fibers were studied by infrared spectroscopy, density measurement and optical microscopy. Two bands at 924 and 1136 cm^–1 were shown to arise from the amorphous phase and assignment of the bands at 936 and 1200 cm^–1 to the crystalline phase were confirmed. We demonstrated that two different infrared spectroscopic methods could be used to determine the total crystallinity of polyamide 66 fibers. One is a calibration method in which the band ratio of 1200 and 1630 cm^–1 is plotted against the crystallinity measured by density measurements. The other one is an independent infrared method. Crystallinity obtained by the independent infrared spectroscopic method showed good agreement with crystallinity observed by density measurement. Infrared dichroism was used to obtain the crystalline orientation using the band at 936 cm^–1. The transition moment angle of 48° was found for the band at 936 cm^–1 with respect to chain axis. Amorphous orientation was obtained using Stein’s equation. Received: 18 September 2000 / Reviewed and accepted: 20 September 2000