尼龙6超韧化研究进展

介绍了超韧尼龙6的最新研究进展.主要介绍几种超韧尼龙6制备方法,其中马来酸酐接枝聚烯烃弹性体与 PA6-无机纳米复合材料共混,能得到刚性、强度和铆性综合性能较好的超韧尼龙.     

尼龙6超韧化研究进展

介绍了超韧尼龙6的最新研究进展.主要介绍了几种超韧尼龙6的制备方法,其中马来酸酐接枝聚烯烃弹性体与尼龙6-无机纳米复合材料共混,能得到刚性、强度和韧性综合性能较好的超韧尼龙.     

耐低温改性尼龙6的研究

介绍在有机过氧化物引发剂作用下马来酸酐和聚乙烯在Ｂｒａｂｅｎｄｅｒ流变仪中反应接枝，以及马来酸酐熔融接枝聚乙烯母料的制备方法和工艺，并用该母料制得适合于扣件挡板座使用的改性尼龙６材料。     

抗静电增强尼龙6的开发和应用

对国内外抗静电增强尼龙６的开发现状、改性机理、主要影响因素、主要技术性能及应用情况作了较详尽的介绍。     

改性尼龙6工程塑料的现状和发展趋势

介绍了通过填充增强、添加助剂、与其它聚合物共混、共聚和分子复合方法改性尼龙６的开发现状与发展方向。     

超韧尼龙结构分析

利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察超韧尼龙的微观结构、得到了清晰的电镜照片,直观地反映了橡胶粒子在尼龙中的分布状态和颗粒大小。探讨了尼龙超韧机理以及影响韧性的几个因素。     

耐磨高强度尼龙6材料的研究

介绍耐磨高强度尼龙６材料的制备和性能。采用复合耐磨剂－玻纤和尼龙６多元复合共混改性技术制备了耐磨高强度尼龙６材料,结果表明,耐磨剂和玻纤对提高材料的力学性能有协同效应、耐磨剂含量对材料的熔点无影响,但能提高材料的结晶度和热变形温度,耐磨剂在玻纤在改性尼龙６中的总量比不超过４０％为宜,其中耐磨剂的含量比不超过１０％为宜。     

抗静电增强尼龙6的研制

以非离子和阴离子型抗静电剂组成复合抗静电体系，用玻璃纤维为增强剂，研制成具有良好的抗静电和机械性能的抗静电增强尼龙６，研究了抗静电复合体系构成，玻璃纤维含量对抗静电增强尼龙６性能的影响，并对其流变性能进行了考察。     

高刚性耐候超韧尼龙的研究

在尼龙6基料中，加入尼龙66、复合相容剂（聚乙烯弹性体/PE-g-MAH），复合增韧剂等，经双螺杆共混挤出，制得高刚性超韧尼龙/聚乙烯/弹性体合金。探讨了复合相容剂的制备条件及其用量、原材料相对粘度、增韧剂等的选用及加入量对合金性能的影响。结果表明，以聚乙烯弹性体和聚乙烯的混合料为载体树脂，在过氧化物含量为0.08%～0.15%，马来酸酐含量为1%～2%时，制得的复合相容剂对合金的增容效果好；相容剂用量为20%时，合金的综合性能较好；简述了产品的应用范围。     

超韧无卤阻燃尼龙6防暴服专用料的研制

采用双螺杆挤出加工工艺,通过添加不同组分制得超韧无卤阻燃尼龙(PA)6材料,比较了不同黏度PA6、增韧剂、阻燃剂及加工工艺对材料性能的影响。结果表明,中黏搭配低黏PA6材料可获得最佳的冲击性能和加工性能;在添加15份马来酸酐接枝乙烯–辛烯共聚物增韧剂时增韧效果最好;小粒径、高含量(红磷)红磷母粒的阻燃效果较好且对体系的力学性能影响较小;Mg(OH)2具有很好的协效阻燃和消烟作用,在添加量为3份时效果最佳;适当的螺杆组合可提高体系的阻燃稳定性。     

Toughenability of Nylon-6 with CaCO3 filler particles: new findings and general principles

The mechanical behavior of Nylon-6 blends modified by two types of CaCO₃ particles of 0.7 and 3.5 μm diameter with particle volume fractions ranging from 0.05 to 0.28 was studied between −30 and 60°C in slow tension, and at 20°C in bending impact. Additional experiments were also carried out at 20°C to determine the plane stress fracture toughness of the blends in Single-Edge-Cracked-Plate configurations; all fracture behavior was followed extensively by SEM fractography.

Experiments demonstrated that the particles are attached to the matrix only through a differential thermal–contraction–pressure and particle separation preceded plastic response in all instances. As a consequence of the above ease in debonding, the yield strengths of the blends drop systematically with increasing particle concentration.

In slow tension all blends showed a well defined plastic stretching response following necking, but the stable post-necking stretch was severely limited by an overabundance of large particle clusters which acted as super-critical flaws to initiate premature termination of stretching. The present findings show that in these blends with their high plastic resistances, critical flaw sizes that trigger brittle response are in the range of 8–12 μm, well under the sizes of many of the particle clusters encountered in the blends.

In contrast with the attractively tough response of the rubber modified Nylon-6 blends of Murato lu et al. [Polymer 36 (1995) 921; Polymer 36 (1995) 4771] all present blends showed only disappointing brittle behavior under Izod impact conditions. This was traced to the development of substantial levels of triaxial tensile stresses arising from only partial separation of rigid particles from the matrix in the early phases of impact response.

Based on the new findings a number of general principles on toughenability with both compliant and rigid particle modification are presented and supported by simple micro mechanical models.     

Orientation and structure development in melt-spun Nylon-6 fibres

A network model is applied to describe the deformation behaviour of melt-spun Nylon-6 fibres obtained at different spinning and drawing conditions. The network draw ratio is determined from analysis of true stress-strain curves and correlated with fibre orientation. From this analysis it appears that the deformation behaviour of Nylon-6 fibres adheres to a pseudo-affine mechanism. The results are discussed in terms of the semicrystalline nature of Nylon-6 fibres. By means of on-line birefringence measurements, wide angle X-ray scattering (WAXS) and solid-state NMR, it is shown that the crystalline and amorphous phases in Nylon-6 respond in a different way to network deformation. In the spin line, an affine (rubber-like) deformation mechanism is observed and this rubber-like network behaviour is transferred to the amorphous phase. After winding and conditioning of the spun fibres, a crystalline phase with relatively high orientation is formed which deforms according to a pseudo-affine mechanism upon further stretching.     

分子复合型尼龙—6合金材料的研究进展

本文概述了分子复合型尼龙－６合金材料的发展及最新研究动态，介绍了近十几年来国内外和种典型尼龙－６分子复合的制备、结构与性能、增强机理，预示了分子复合型尼龙－６合金材料的开发前景。     

The Influence of Interfacial Adhesion on the Predicted Young's Modulus of Mica-Reinforced Nylon-6

Particle-filled polymer composites have become attractive because of their wide applications and low cost. Various factors influence the mechanical properties of thermoplastic composites. Of these, the aspect ratio of the reinforcement, interfacial adhesion, and binder content are the most important. Other than these, the particle size and particle size distribution of the reinforcement also influence the mechanical properties. In this paper, injection molded mica composites were investigated, using nylon-6 as a binder. Many models are available to predict the Young's modulus of the composites. A theoretical model for Young's modulus by Lewis and Nielsen was used to predict the Young's modulus of the composites. Tetra isopropyl titanate (TYZOR® TPT) was used to modify the adhesion between the reinforcement and the binder by mixing it with the reinforcement prior to compounding. It was found that Young's modulus was greater than the predicted values.     

季鏻盐改性黏土及其对尼龙6性能的影响

首先采用季鏻盐作为插层剂对钠基黏土进行插层改性,制备有机黏土,再与尼龙6熔融共混,成功制备尼龙6/有机黏土纳米复合材料。XRD测试结果表明:季鏻盐改性黏土可以与尼龙6形成纳米复合材料。转矩流变仪的测试结果显示:有机黏土能够略微改善尼龙6树脂的加工性能。力学性能的测试结果显示:有机黏土的含量在3%~5%范围内其,纳米复合材料的力学性能最佳。     

尼龙-6的拉伸多次屈服行为及球晶形态的研究

研究了不同拉伸速度下尼龙-6的多次屈服成颈行为,并采用生物显微镜研究了尼龙-6的球晶形貌。结果表明：在拉伸速率低于50m／min的条件下,可观察到尼龙-6明显的多次屈服成颈行为,这应与拉伸条件下球晶演变形成的微纤维的缺陷有关：采用生物显微镜,可观察到尼龙-6球晶中的发射状微纤、球晶形貌和晶界。     

In situ Polymerization of Multi-Walled Carbon Nanotube/Nylon-6 Nanocomposites and Their Electrospun Nanofibers

Multiwalled carbon nanotube/nylon-6 nanocomposites (MWNT/nylon-6) were prepared by in situ polymerization, whereby functionalized MWNTs (F-MWNTs) and pristine MWNTs (P-MWNTs) were used as reinforcing materials. The F-MWNTs were functionalized by Friedel-Crafts acylation, which introduced aromatic amine (COC₆H₄-NH₂) groups onto the side wall. Scanning electron microscopy (SEM) images obtained from the fractured surfaces of the nanocomposites showed that the F-MWNTs in the nylon-6 matrix were well dispersed as compared to those of the P-MWNTs. Both nanocomposites could be electrospun into nanofibers in which the MWNTs were embedded and oriented along the nanofiber axis, as confirmed by transmission electron microscopy. The specific strength and modulus of the MWNTs-reinforced nanofibers increased as compared to those of the neat nylon-6 nanofibers. The crystal structure of the nylon-6 in the MWNT/nylon-6 nanofibers was mostly γ-phase, although that of the MWNT/nylon-6 films, which were prepared by hot-pressing the pellets between two aluminum plates and then quenching them in icy water, was mostly α-phase, indicating that the shear force during electrospinning might favor the γ-phase, similarly to the conventional fiber spinning.     

Rheology of Short Nylon-6 Fiber Reinforced Styrene-Butadiene Rubber

ABSTRACT

The rheological characteristics of short Nylon-6 fiber reinforced styrene butadiene rubber (SBR) were studied using a capillary rheometer. The study was done with respect to the effect of shear rate, fiber concentration, and temperature on shear viscosity and die swell. All the melts showed pseudoplastic nature, which decreased with increasing temperature. Shear viscosity increased in the presence of fibers. Introduction of fiber reduces the temperature sensitivity of the rubber matrix. A reduction in die swell was found in presence of fibers.