PPTA／尼龙1010分子复合材料流变行为的研究

本文介绍用共沉淀法制得PPTA/尼龙1010分子复合材料,讨论了不同组成的分子复合材料的流变行为,发现PPTA/尼龙1010分子复合材料的表观熔体粘度比纯尼龙1010的大,且熔体粘度对温度变化的敏感性不象尼龙1010那样突出。     

尼龙1010/硅灰石复合材料的热性能研究

通过熔融共混法制备了尼龙1010/硅灰石复合材料,研究了复合材料的热膨胀性能、热变形温度、热分解过程和熔融及结晶行为。结果表明,与纯尼龙1010相比,尼龙1010/硅灰石复合材料的热膨胀系数及其温度依赖性大幅下降。当硅灰石质量分数为70%时,复合材料的热膨胀系数及其随温度的增加率分别只有纯尼龙1010的29%和15%。复合材料的热变形温度随硅灰石含量的增加大幅升高,当硅灰石质量分数为70%时,热变形温度由纯尼龙1010的63℃升高到178℃;复合材料的起始热分解温度和最大热分解速率时的温度均明显升高。硅灰石的加入显著提高了尼龙1010的热稳定性。尼龙1010的熔融温度和结晶温度不受硅灰石的影响,复合材料熔体仍具有良好的加工成型性。     

偶联剂处理纳米SiO2对尼龙1010力学与摩擦学性能的影响

用A171和KH550 2种硅烷偶联剂对纳米SiO2进行分散处理,然后用注射成型法制备了纳米SiO2/尼龙1010复合材料。研究了改性处理纳米SiO2对尼龙1010复合材料的结晶性能、力学性能以及摩擦学性能的影响。结果表明:纳米SiO2表面的改性处理均使尼龙1010基体的结晶度降低,而拉伸强度、硬度和耐磨性提高。A171处理纳米SiO2/尼龙1010复合材料的断裂伸长率大于纯尼龙1010。改性处理纳米SiO2使尼龙1010复合材料的摩擦因数降低。     

尼龙11/空心玻璃微珠复合材料流变行为研究

采用XLY–Ⅱ型毛细管流变仪研究了尼龙(PA)11/空心玻璃微珠(HGB)复合材料的流变行为。结果表明,PA11/HGB复合材料熔体为假塑性流体,呈现出剪切变稀的行为。随HGB含量的增加,复合材料的表观黏度和粘流活化能总体上增大,这表明复合材料熔体对温度敏感性较大。     

钛酸酯偶联剂对尼龙1010填充体系流变性的影响

本文研究不同结构的钛酸酯偶联剂处理CaCO_3填料填充尼龙1010体系的熔体流动性。从体系粘度下降程度,结合偶联机理判断偶联剂的偶联效果。     

PA1010/纳米橡胶/POE-g-MAH共混物的流变性能研究

用高压毛细管流变仪研究了PA1010／纳米橡胶/POE—g—MAH共混物的流变性能。结果表明,在240—270℃及剪切速率100-2500s^-1时,熔体为假塑性流体。加入纳米橡胶明显地降低了共混物熔体的非牛顿指数,并且使尼龙1010的粘流活化能较大幅度地降低,但橡胶含量增加对粘流活化能影响不明显。随着橡胶含量的增加,熔体的粘度逐渐增大,橡胶含量为15％时达到最大值。     

PA1010含量对PLA/PA1010共混物性能的影响

通过双螺杆挤出机制备了不同尼龙1010含量的聚乳酸/尼龙1010 (PLA/PA1010)共混物。用差示扫描量热分析(DSC)、熔体质量流动速率(MFR)、扫描电镜(SEM)、力学性能测试等方法研究了PLA/PA1010共混物的结晶行为、断面形态和力学性能。研究表明,加入PA1010后,改善了聚乳酸的结晶能力,特别是当PA1010质量分数为10%时,对促进聚乳酸的结晶比较有效。当PA1010质量分数为10%时,熔体黏度最小,熔体质量流动速率最好,充分显示出PA1010较好的熔体流动性。共混物力学性能测试结果表明,当PA1010质量分数达到10%时,共混物的断裂伸长率和缺口冲击强度分别达到最佳值;分别为13. 43%和3. 84 k J/m~2,与纯PLA相比分别提高了52. 79%和19. 63%。     

原位缩聚合成含聚芳酰胺/酯的微相复合材料Ⅳ.全芳香聚酰胺与聚砜的微相复合材料制备

以原位缩聚方法合成了PPTA/PSF的微相复合材料。FTIR、DSC等分析结果表明,PPTA/PSF微相复合材料较PPTA/PBT-PTMG分子链间存在着更强的相互作用,PPTA对基体聚合物的力学性能有较大的提高。初步结果表明,加入第三单体双酚A在一定程度上提高了复合材料的抗张强度和断裂伸长率,但是模量有所下降。     

尼龙11/白炭黑纳米复合材料的流变性能

采用原位聚合的方法制备尼龙11/白炭黑纳米复合材料,并利用XLY-Ⅱ型毛细管流变仪测试其流变行为,流变曲线分析结果表明:尼龙11及其纳米复合材料均为假塑性流体,呈现出切力变稀的现象.白炭黑含量时体系的表观黏度有不同程度的影响,但对黏流活化能影响不大,说明熔体的流变性能对温度的敏感性不强.     

LiCl对PA1010/LiCl复合材料结构与性能的影响

采用熔融挤出的方法制备了尼龙1010/氯化锂(PA1010/Li Cl)复合材料,研究了Li Cl对PA1010结晶行为和力学性能的影响。结果表明:Li Cl的加入能降低PA1010的结晶温度,使PA1010的结晶度降低,提高复合材料的透明性,当Li Cl质量分数为6%时,PA1010已经完全不能结晶。并且Li Cl的加入能够提高复合材料的拉伸强度和冲击强度,当Li Cl质量分数为4%时,复合材料的冲击强度最大。     

Rheological and mechanical characteristics of poly-p-phenylene terephthalamide/nylon molecular and particulate composites

Poly-p-phenylene terephthalamide (PPTA) and nylons (nylon 6, 66, 11, and 12) molecular and particulate composites were examined with emphasis on rheological, mechanical, and morphological characteristics. These molecular composites were prepared by coagulation in water from isotropic ternary sulfuric acid solutions. Upon heating above the crystal melting temperatures of nylons, the molecular composites undergo phase separation and become two-phase particulate composites. Shear viscosity measurements indicate that the viscosity of nylon 6 and 66 systems has increased for an order of magnitude because of the presence of PPTA, but decreased in the case of nylon 11 and 12 systems. PPTA/nylon 6 and 66 systems exhibit yield behavior, particularly with high PPTA contents. Measurements show an extrudate swell of around 1 in all composition ranges and shear rates. Scanning electron microscopic investigations of low PPTA content particulate composites reveal spherical or long fibrillar morphology of PPTA phase dispersed in nylon matrices. Wide angle X-ray diffraction investigations show no preferred orientation in the extrudates, but biaxial orientation in the case of compressed films. The study on mechanical properties of extrudates of 5 to 10 wt.% PPTA compositions exhibits significant improvement in tensile modulus and tensile strength. The heat-treated extrudates show further increase in tensile modulus and tensile strength, as compared with the unannealed samples, but the elongation at break decreases.     

Miscibility in poly-p-phenylene terephthalamide/nylon 6 and nylon 66 molecular composites

Miscibility and crystallization of poly-p-phenylene terephthalamide (PPTA)/nylon 6 and nylon 66 composites prepared by coagulation of isotropic ternary sulfuric acid solutions were studied. The apparent crystallinity of nylon 6 and nylon 66 in molecular composites was investigated by differential scanning calorimetry and Fourier transform infrared spectroscopy. The solvation of nylon 6 crystals in PPTA matrix was observed when the PPTA content exceeds 70 wt%. Cross-hydrogen bonding seems to be responsible for the virtual disappearance of nylon 6 crystals. Specific interaction between PPTA and nylon 6 macromolecules and phase separation during thermal treatment has been discussed.     

The phase inversion and morphology of nylon 1010/polypropylene blends

Noncompatibilized and compatibilized blends of nylon 1010/PP blends having five different viscosity ratios were prepared by melt extrusion. Glycidyl methacrylate-grafted-polypro-pylene (PP-g-GMA) was used as the compatibilizer to enbance the adhesion between the two polymers and to stabilize the blend morphology. The effect of the viscosity ratio on the morphology of nylon 1010/polypropylene blends was investigated, with primary attention to the phase-inversion behavior and the average particle size of the dispersed phase. The relationship between the mechanical properties and the phase-inversion composition was investigated as well. Investigation of the morphology of the blends by microscopy indicated that the smaller the viscosity ratio (ηpp/ηpa) the smaller was the polypropylene concentration at which the phase inversion took place and polypropylene became the continuous phase. The compatibilizer induced a sharp reduction of particle size, but did not have a major effect on the phase-inversion point. An improvement in the mechanical properties was found when nylon 1010 provided the matrix phase. © 1996 John Wiley & Sons, Inc.     

芳纶浆粕与聚己内酰胺复合的初步研究

对芳纶浆粕与聚己内酰胺复合进行了初步研究，实验表明，随芳浆粕含量的增加，复合材料的断裂伸长率和缺口冲击强度下降，拉伸屈服强度增加，拉伸断裂强度先降后增，芳浆粕是聚己内酰胺的α成核剂，复合材料的维卡热变形温度大幅度提高，熔体粘度增加，但粘流活化能不变。对芳纶浆粕进行浸渍处理可提高共混效果。     

发泡尼龙1010流变性能及成型的研究

采用毛细管流变仪对不同发泡剂用量的PA1010发泡体系的流变行为及体系活化变化进行了研究。结果表明，PA1010发泡体系仍属于非牛顿流体类型，其粘度比纯熔体降低约20％，且气体含量越多，粘度下降越大；气体／聚合物体系的粘流活化能要比纯聚合物小。通过调节配方和成型加工工艺设计，采用注射成型方法制成了汽车用浮子制件。     

PA1010/TPU共混物流变性能的研究

以尼龙1010(PA1010)为基体，以聚酯型热塑性聚氨酯弹性体(TPU)为增韧剂，采用Haake PTW16／25p型双螺杆挤出机制备了PA1010／TPU共混增韧尼龙材料。测试了PA1010／TPU共混物的表观粘度、非牛顿指数等流变参数，并重点讨论了其流变性能。实验结果表明：共混物熔体的表现粘度随剪切速率的增大而降低，非牛顿指数小于1，符合假塑性流体流动规律。此外共混物的表观粘度随着组成和温度的变化呈现了一种极为特殊的变化行为。即在相同温度下，共混物的表观粘度随着TPU含量增加而增加；在相同组成下，共混物的表观粘度随着温度升高而升高。     

三元尼龙对氯化聚乙烯性能的影响

采用三元尼龙改性氯化聚乙烯（CPE）,研究了尼龙用量对CPE共混胶加工性能和物理机械性能、稳定性、耐油性能的影响。结果表明：CPE和尼龙具有较好的相容性,随着尼龙用量的增加,CPE共混胶的强度以及模量大大提高,耐油及耐热性能亦明显改善,当尼龙用量为40份时,共混物获得较为优异的综合性能;此外,尼龙与CPE共混后可提高共混胶剪切粘度,改善其加工性能,扩大了其应用范围。     

MC尼龙/稀土纳米复合材料制备的反应动力学研究

测定了MC尼龙和MC尼龙/稀土纳米复合材料制备的温度与时间关系曲线,用非等温反应动力学方法对数据进行处理,用多元回归法确定其表观动力学参数。结果表明:MC尼龙和MC尼龙/稀土纳米复合材料制备过程的动力学特征基本相似,是一个并行的聚合/结晶过程;稀土纳米氧化物对MC尼龙制备的阴离子聚合反应有促进作用;MC尼龙和MC尼龙/稀土纳米复合材料制备过程的表观活化能在92~145kJ/mol之间,反应级数在0.9~1之间,频率因子在108~1014之间,MC尼龙和MC尼龙/稀土纳米复合材料制备过程由化学反应步骤控制。     

Melting‐reactive dyes for mass coloration of nylon based on blend compatibilization: Perylene‐3,4,9,10‐tetracarboxylic acid dianhydride

The mass coloration of nylon‐1010 with a melting‐reactive dye, an economically favorable and environmentally friendly method of coloration, is described. Perylene‐3,4,9,10‐tetracarboxylic acid dianhydride (PTAD) was used as a melting‐reactive dye for nylon‐1010, and it showed high thermal stability. A chain‐extending reaction was confirmed by an ultraviolet–visible spectroscopic analysis. The effect of the proportion of added PTAD on the intrinsic viscosity of the polymer was studied, and increased amounts resulted in increased intrinsic viscosity. The light fastness of the colored fibers was found to be 4. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2164–2167, 2002     

Epitaxial crystallization of nylon 6 cast from solution on the surface of poly(p-phenylene terephthalamide) filament

Poly(p-phenylene terephthalamide) (PPTA) fiber has the characteristics of high modulus and strength, and has been employed as the reinforcement in composite materials. The interfacial interaction between the PPTA filament and nylon 6 matrix has been investigated to make use of these characteristics of PPTA in fiber-reinforced composite systems. In the case of composites composed of the PPTA filament and nylon 6, two types of expitaxial crystallization have been observed depending on the concentration of a formic acid solution. From concentrated solution, nylon 6 forms a columnar cystal around the PPTA filament. A two-dimensional spherulite model, (i.e., a disk shape) is proposed for the aggregated structure of nylon 6 chains on the basis of wide-angles x-ray diffraction, small-angle x-ray scattering studies, and scanning electron microscopic ebservation. The a*-axis of the nylon 6 crystal is directed radially in its columnar crystal. In the inner portion, close to the interface, the be-plane is in contact with the surface of the PPTA filament, also, the directions of the b- and c-axes are paral el and perpendicular to the PPTA filament axis, respectively. On the other hand, their axes rotate about the a*-axis in the outer portion, far from the interface region. Furthermore, a different type of epitaxy was observed in the case of crystallization from a dilute solution of nylon 6 in formic acid. These two types of crystal growth were investigated from the view of crystallization condition and crystallographic lattice matching at the interface region between the PPTA filament a nylon 6. It is concluded that the hydrogen bonding between PPTA and nylon 6 molecules at the interface plays an important role for epitaxial crystallization, in addition to lattice matching.