蒙脱土插层尼龙66及其合金力学性能研究

先采用有机化蒙脱土(org MMT)插层尼龙66制得了PA66/PP纳米复合材料,对其力学性能进行了测试。试验结果表明:MMT含量为7%时,PA66/MMT的各项性能达到最优,但是材料的韧性仍较差,进而采用与聚丙烯共混改性的方法增韧制得PA66/PP/MMT纳米复合材料,当MMT含量为5%,PA66∶PP为80∶20时,材料的冲击强度提高45 4%,而其他各项性能基本保持不变。     

工程塑料尼龙66的增韧改性研究状况

总结了尼龙66强度和韧性的几个主要影响因素,并综述了尼龙66的几种改性技术方法,包括增容增韧、增强增韧、纳米填充超增韧等手段提高尼龙66的综合性能。     

无卤阻燃增韧增强PA66的研究进展

尼龙66作为重要的工程塑料,在汽车和电子等行业有着广泛的应用,开发无卤阻燃增强增韧技术是目前尼龙66改性领域的一个新热点。文章综述了近年来尼龙66改性及无卤阻燃的研究与进展,为研究无卤阻燃增强增韧的尼龙66提供一定的理论指导。     

纳米硫酸钡增强增韧尼龙66

通过熔融共混法制备了纳米硫酸钡增强增韧尼龙66复合材料。研究了纳米硫酸钡含量对增强增韧尼龙66复合材料力学性能的影响。结果表明，纳米硫酸钡对尼龙66有显著的增强增韧作用。尼龙66的韧性、刚性和强度随着纳米硫酸钡含量的增加先增后减，在纳米硫酸钡质量分数为3％时，力学性能最优；对比空白样，缺口冲击强度提高了17．1％，弯曲强度和模量分别提高了5．74％和11．57％，拉伸强度和模量稍有提高。     

成核剂对尼龙66结晶及力学性能的影响研究

研究了不同成核剂对尼龙66结晶及力学性能的影响。结果表明,成核剂的加入使尼龙66结晶速率加快,结晶温度提高,重熔融过程出现双峰,其低温峰值比尼龙66峰值低8℃,可能是生成β晶所致,成核剂使尼龙66的结晶变细。不同成核剂对尼龙66的力学性能有不同的影响,其中成核剂G23、G205、MgO使尼龙66的强度提高;CaF2使其韧性增加;滑石粉的效果介于其间。     

硅灰石填充改性尼龙66的研究

研究了针状硅灰石粉填充对尼龙66的结构和性能的影响。研究表明,随着硅灰石填充量的增加,材料的冲击强度大幅度地提高,拉伸强度、弯曲强度则较为复杂,且复合材料的耐热性能、尺寸稳定性得到了很大的提高;随着硅灰石细度的增加,硅灰石增强尼龙66的缺口冲击强度、拉伸强度、弯曲强度均增加;将硅灰石填充材料表面以适量的偶联剂进行改性处理后,借助于扫描电子显微镜,并结合硅灰石粉的微观形态及偶联剂的作用原理,探讨了针状硅灰石粉对尼龙66力学性能的影响。     

尼龙66和马来酸酐LDPE接枝共聚物的力学性能

将马来酸酐和LDPE进行接枝反应后得到的共聚物，和尼龙66共混，由于LDPE－g-MAH上的酸酐基团与尼龙66上的胺基相互作用，它们有很好的相容性，随着LDPE－g-MAH加入量的增加，尼龙66的冲击韧性有很大提高。     

尼龙66/蒙脱土/SiO2纳米复合材料的研究

以蒙脱土和纳米SiO2为增强增韧改性剂,制备较高性能的尼龙66纳米复合材料。测试了材料的力学性能和燃烧性能,通过扫描电子显微镜观察了材料的燃烧炭层表面。结果表明,当蒙脱土与SiO2的质量分数分别为3.0%和1.5%时,材料的拉伸强度较纯尼龙66提高了9.84%;冲击强度为4.64kJ/m2,较纯尼龙66提高了10.21%。蒙脱土与SiO2的加入大大提高了材料的高温成炭率,改善了燃烧炭层表面,从而使材料的极限氧指数有所提高。     

Effect of Dye‐Bath pH on Photostability of Dyed Nylon 66

Nylon 66 films were dyed in aqueous dye‐bath with C. I. Acid Blue 25 (1‐amino‐4‐(aminophenyl)‐2‐anthraquinone sodium sulfonate) at various pH values ranging from 2.0 to 7.0. Films were exposed to polychromatic irradiation (λ ⪈ 290 nm) at 60°C in air. The extent of photo‐oxidation was monitored by FT‐IR spectroscopy. Fading of dye with polychromatic irradiation was monitored by UV spectroscopy. We observed a peculiar effect of dye‐bath pH on the photostability of dyed nylon 66. Samples were more stable when dyed at pH 3 and above that (up to pH 7), whereas the samples dyed at pH < 3.0 showed sensitized photo‐oxidative degradation in nylon 66. Formation of quaternary ammonium salt on dye‐chromophore was considered responsible for the pH‐controlled behavior of anthraquinone acid dyes. The dyeing pH significantly effects the photofading behavior of dyed samples. The effect of dye‐bath pH on photofading of the dyed samples was more pronounced at lower dyeing pH and prevailed up to pH 4. The hydronium ion concentration was considered to be responsible for the enhanced fading of dye for the samples dyed at the lower pH.     

插层剂对PA66/蒙脱土纳米复合材料性能影响

将不同插层剂改性的蒙脱土与尼龙66(PA66)通过熔融共混制得了纳米复合材料,对复合材料的热变形温度和力学性能进行了研究。结果表明,与纯PA66相比,3种插层剂改性的蒙脱土／PA66纳米复合材料的热变形温度、弯曲模量、弯曲强度均有明显提高,拉伸模量和屈服强度也有所提高,但断裂伸长率和缺口冲击强度则明显下降;含极性羟基的插层剂对复合材料的综合改性效果较好,含2个长链非极性烃基的插层剂改性效果较差;加入环氧树脂后,复合材料的热变形温度、拉伸模量和弯曲模量有所降低,屈服强度、弯曲强度、断裂伸长率和缺口冲击强度则有所增加。     

玻璃纤维增强MC尼龙力学性能的研究

用玻璃纤维对MC尼龙复合材料进行改性,研究了玻璃纤维含量及长度对MC尼龙复合材料力学性能的影响。结果表明:玻纤含量50%的MC尼龙同玻纤含量40%的MC尼龙相比,冲击强度、拉伸强度、弯曲强度分别提高29.63%、5.43%,6.47%;MC尼龙复合材料的拉伸强度、弯曲强度及冲击强度随玻璃纤维长度的增长而增加,玻纤的长度越长,MC尼龙复合料力学性能提升效果越好;MC尼龙复合材料弯曲强度与玻纤重均长度为正相关关系,随着玻纤重均长度增大而增大。     

尼龙66/煤系高岭土复合材料的制备及性能研究

采用熔融共混法制备了尼龙66/煤系高岭土复合材料,研究了不同高岭土表面处理法和偶联剂用量对复合材料力学性能、颜色和流变性能的影响。结果表明,用不同偶联剂对高岭土进行表面改性处理,均可提高复合材料的冲击韧性,且以KH–550偶联剂质量分数为1.5%时复合材料综合力学性能最佳。随着偶联剂KH–550用量增加,复合材料的颜色由黄黑逐渐变亮白,熔体流动速率(MFR)增大,当KH–550质量分数为1.5%时,复合材料的MFR为14.6 g/10 min,具有很好的流变性能。     

High temperature zone‐drawing of nylon 66 microfiber prepared by CO2 laser‐thinning

A high temperature zone‐drawing method was applied to a nylon 66 microfiber, obtained by using CO₂ laser‐thinning, to develop its mechanical properties. The microfiber used for the high temperature zone‐drawing was prepared by winding at 150 m min^?1 the microfiber obtained by irradiating the laser at 4.0 W cm^?2 to an original fiber with a diameter of 50 μm, and had a diameter of 9.6 μm and a birefringence of 0.019. The high temperature zone‐drawing was carried out in two steps; the first drawing was carried out at a temperature of 230°C at supplying and winding speeds of 0.266 and 0.797 m min^?1, the second at 250°C at supplying and winding speeds of 0.266 and 0.425 m min^?1, respectively. The diameter of the microfiber decreased, and its birefringence increased stepwise with the processing. The high temperature zone‐drawn microfiber finally obtained had a diameter of 4.2 μm, a birefringence of 0.079, total draw ratio of 4.8, tensile modulus of 12 GPa, and tensile strength of 1.0 GPa. The wide‐angle X‐ray diffraction photograph of the drawn microfiber showed the existence of highly oriented crystallites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 42–47, 2006     

Mechanical Properties of Hemp‐Fibre‐Reinforced Euphorbia Composites

A composite material consisting of hydroxide‐modified hemp fibres and euphorbia resin was produced. The composites were tested in tension, short‐beam interlaminar shear stress and in impact. There was an increase in the tensile strength and modulus for resins with high‐hydroxyl‐group based composites. Similar results were obtained for interlaminar shear stress while low‐hydroxyl group euphorbia resin based composites exhibited high impact strength. The euphorbia resin with high hydroxyl content yielded composites with high stiffness. The use of euphorbia‐based resins in composite manufacture increases the value of the euphorbia oil as well as creating a new route of composite manufacturing.

     

Review on Various Compatibilizers and its Effect on Mechanical Properties of Compatibilized Nylon Blends

Nylon 6 blends such as polyamide 6/acrylonitrile–butadiene–styrene and polyamide 6/polypropylene are among the commercially successful blends, having varied applications ranging from automobile parts to construction industry. Nylon 6 blends can be made supertough based on other polymers involved. Nylon 6 blends are immiscible, and the use of compatibilizers can increase the interfacial adhesion between the polymers. Amount of compatibilizer plays a key role in defining the size distribution, dispersion, and adhesion between the polymers. In this paper, a detailed review on the compatibilizers used and the effect of compatibilizer on the mechanical and impact properties of the blends has been given.     

Morphology,Thermal and Mechanical Properties of Poly(propylene) Fibre‐Matrix Composites

Preparation and properties of poly(propylene)‐poly(propylene) composites have been investigated. Poly(propylene) fibres of varying diameter have been incorporated in a random ethylene co‐poly(propylene). The composites prepared from the same semi‐crystalline polymer in the matrix and reinforcement have lead to inherently strong interfacial bonding between the two phases of the same polymer. The composites demonstrated enhanced stiffness, which increased with fibre diameter. The structure, thermal, static and mechanical properties of poly(propylene) long fibre reinforced random co‐poly(propylene) composites have been studied with reference to the fibre diameter. The matrix and fibre components retained their separate melting temperatures. After melting, the two phases remained separate and showed their individual crystallization temperatures on cooling, and melting temperatures on a second heating. The melting temperature of the poly(propylene) fibres increased after formation of the composites. The compression molding of the composites at a temperature below the melting temperature of the fibres caused annealing of the fibre crystals. By incorporation of long poly(propylene) fibre into random co‐poly(propylene), the glass transition, storage and static modulus have been found to be increasing and composite with the largest fibre diameter shows better properties. Transcrystallization of the matrix poly(propylene) was observed.

Optical microscopy of composites with fibre diameter 68 μm.     

玻璃微珠增强改性聚酰胺66的力学性能研究

采用熔融共混挤出的方法,制备了不同添加量的微米玻璃微珠（GB）填充聚酰胺66的复合材料,考察了玻璃微珠对聚酰胺66的力学性能及结晶特性的影响。结果表明,GB的加入改善了材料的结晶性能。当GB的添加质量分数小于4％时,复合材料的冲击强度与聚酰胺66相当,而硬度、拉伸强度大幅提高,其中GB含量2％时材料的综合性能较好。     

尼龙66/针状硅灰石复合材料的制备和性能研究

以针状硅灰石为填料,用双螺杆挤出机共混制备尼龙(PA)66/硅灰石复合材料,研究了硅灰石含量、处理方法和加工工艺对复合材料性能的影响,并观察了硅灰石共混前后和PA66/硅灰石复合材料冲击试样断面的形貌。结果表明,硅灰石用KH–560预处理时比用KH–550预处理所制备的PA66/硅灰石复合材料的力学性能好。硅灰石以侧喂料方式加入并采用较低的螺杆转速时,可使复合材料具有较高的力学性能。随着硅灰石含量的增加,复合材料的拉伸强度、弯曲强度和缺口冲击强度都大幅提高。经过1%KH560预处理的硅灰石质量分数在30%时,PA66/硅灰石复合材料的力学性能最好。     

MCA不同加料方式对尼龙66力学性能的影响

在双螺杆挤出改性工艺下,研究了不同的加料方式下三聚氰胺氰尿酸盐(MCA)填充尼龙66材料的弯曲和缺口冲击性能的变化。对材料进行弯曲、冲击试验测试。结果表明,侧喂料的弯曲模量比主喂料的结果低以及侧喂料的悬臂梁缺口冲击强度比主喂料的高。其主要原因是由于一定比例条件下主喂料的分散性较好,而MCA在加工过程以及最后改性材料中呈刚性片状颗粒的状态。因此MCA材料分散越是均匀材料的刚性越好。另外MCA粒子的粒径较大,因此材料在成型过程中分散越均匀,材料里面应力缺陷点越多,导致材料的冲击性能下降。     

废胶粉、滑石粉改性PA66/GF复合材料的制备与性能

采用硅烷偶联剂KH560表面改性废胶粉(WRP)、环氧树脂E44改性滑石粉(Talc),以尼龙(PA)66/玻璃纤维(GF)复合材料为基体,制备了WRP,Talc及两者协同改性的PA66/GF复合材料,研究了WRP,Talc及两者协同作用对复合材料力学性能、结晶性能和热稳定性能的影响。结果表明,当3份WRP经过1份KH560处理后,其与PA66/GF基体间的界面粘结性明显得到改善,其改性的复合材料弯曲强度和冲击强度最高,分别比PA66/GF基体提高了11.09%和2.05%。当1份Talc经过3份E44处理后,其在基体中具有良好的分散性,改性的复合材料弯曲强度和冲击强度达到最大,分别比基体材料提高了13.89%和8.42%。WRP与Talc均能促进复合材料的结晶,但两者协同作用对复合材料结晶性能没有明显的影响。采用1份KH560处理的3份WRP协同3份E44处理的1份Talc对复合材料进行改性,可使弯曲强度和冲击强度相比基体分别提高16.97%和6.25%,且使复合材料具有良好的热稳定性能,达到了低成本WRP和Talc改性制备高性能橡塑复合材料的目的。