超高分子量聚乙烯改性尼龙6复合材料的力学性能研究

通过挤出方法制备了尼龙6（PA6）／超高分子量聚乙烯（UHMWPE）复合材料,考察了复合材料摩擦学性能和力学性能。用光学显微镜观察分析了复合材料磨损表面形貌。结果表明：复合材料摩擦性能较纯尼龙有一定的提高,当UHMWPE含量为5％和10％时,复合材料耐磨减摩性较好。但随着UHM-WPE含量的增加,复合材料的硬度、拉伸强度、伸长率有所下降。     

PA6/碳纳米管复合材料的力学性能与结构

研究了碳纳米管的加入对PA6复合材料的力学性能的影响。并用扫描电镜和特性粘数法对结构与性能的关系进行了初步探讨，结果表明，碳纳米管的加入提高了PA6的强度，此时碳纳米管能够以纳米状态均匀地分布在基体中，碳纳米管在原位复合过程中没有对高分子链段的增长带来负面影响，反而使PA6的聚合程度略有增大。     

尼龙6改性研究

采用经化学改性的芳纶纤维增强尼龙6,并通过红外光谱和电镜分析其界面层,结果表明芳纶纤维经异氰酸酯化及封端稳定处理后,其表面所接技的不稳定基团-NCO转化成稳定的-NHCO-,封端结果较为明显;改性后纤维表面附有接枝物,从而使表面粗糙程度大大增加。用挤出和注塑的方法加工了PA6／Kevlar纤维（KF）复合材料,研究了它的拉伸、弯曲和冲击性能破坏形态。力学性能测试表明了改性尼龙6复合材料的拉伸和弯曲强度得到了改善,但冲击性能略为下降。     

高流动性尼龙6/改性氧化石墨烯复合材料的力学性能

用改进的Hummers法制备氧化石墨烯(GO),用十六烷基三甲基溴化铵(CTAB)对其进行改性得有机改性氧化石墨烯(OGO),再将OGO与高流动性PA6进行熔融共混,制备了高流动性PA6/OGO复合材料,对复合材料的力学性能进行了研究。结果表明:当OGO含量为0.6 wt%时,复合材料的力学性能最佳,拉伸强度提高17.8%,断裂伸长率提高4.7%,弯曲模量提高40.8%,实现了对高流动性尼龙6力学性能的改善。     

长玻纤填充尼龙6复合材料研究

采用熔体浸渍工艺制备长玻纤增强PA6复合材料。研究了玻纤种类、玻纤含量长度、界面改性等对复合材料力学性能及电性能的影响。试验结果表明：在玻纤含量35％时,切粒长度7mm,粒径3．5mm时,复合材料表现出优异的力学性能和电性能。     

PA/POE/OMMT复合材料的制备及性能研究

分别以三种常用的尼龙(PA6,PA1010,PA11)为基体树脂,以乙烯–辛烯共聚物(POE)和有机改性蒙脱土(OMMT)为增韧增强改性剂,采用熔融共混方法制备了PA/POE/OMMT复合材料,并研究了复合材料的力学性能。结果表明,当OMMT的添加量为3%时,三种复合材料(PA6/POE/OMMT,PA1010/POE/OMMT,PA11/POE/OMMT)的综合力学性能最佳,复合材料的冲击强度达到56.14,53.15,59.09 kJ/m2,分别为纯PA树脂的10.3,6.5,6.0倍。     

玻璃纤维改性尼龙复合材料现状

玻璃纤维(GF)改性尼龙(PA)复合材料是一种高性能工程塑料,其应用范围十分广泛。对影响PA/GF复合材料性能的重要因素进行综述。阐述了GF与PA基体界面作用力、GF的直径、挤出机螺杆组合及GF与其他无机填料的协同作用对PA/GF复合材料性能的影响规律。结果表明,对GF进行有机化改性或在PA基体中添加其他改性剂能显著提升PA和GF界面作用力,从而提高PA/GF复合材料的力学性能。GF的直径越小,PA/GF复合材料的力学性能越好。螺杆组合对PA/GF复合材料中GF的长度和分散性具有重要影响,联合使用齿形盘、反向齿形盘与啮合块,制备的PA/GF复合材料性能更好。与单独采用GF改性的PA复合材料相比,当其他无机填料与GF协同使用时,PA/GF复合材料的力学性能较好。最后,对未来GF改性PA复合材料的研究方向进行了展望。     

ABS/OMMT、PA6/OMMT复合材料形态及性能

熔融挤出制备了有机蒙脱土(OMMT)含量不同的ABS/OMMT,PA6/OMMT复合材料,用X射线衍射仪(XRD)、透射电子显微镜(TEM)等仪器研究OMMT分别在ABS、PA6基体中的分布情况及对其力学性能的影响.结果表明:在ABS/OMMT复合材料中,OMMT主要为插层结构,大部分OMMT片层以聚集状态存在;而对PA6/OMMT复合材料,OMMT片层主要以剥离形态分布在PA6基体相中;随着OMMT含量增加,ABS/OMMT复合材料的拉伸、弯曲强度及弯曲模量都先上升后下降,且当OMMT含量在3份时性能较好,其缺口冲击强度呈下降趋势;PA6/OMMT复合材料在OMMT含量为3份时,其拉伸、弯曲强度和弯曲模量都出现极值现象,而缺口冲击强度线性降低.由于OMMT与PA6有较好的亲和力,在PA6中分散性较好,使PA6/OMMT复合材料的综合力学性能比ABS/OMMT复合材料的优异.     

PA6/POE/OMMT纳米复合材料的流变行为

使用毛细管流变仪研究了尼龙6/乙烯-辛烯共聚物/有机改性蒙脱土(PA6/POE/OMMT)纳米复合材料的流变行为,并对lgΥω-lgγω、lgηα-lgγω、lgηα-1/T曲线进行了分析.研究结果表明,PA6/POE/OMMT纳米复合材料为假塑性流体,其表观粘度随着剪切应力的增加而降低;OMMT使得PA6/POE纳米...     

PA6／OMMT纳米复合材料的炭层残余物的形成过程研究

通过SEM对PA6／OMMT纳米复合材料炭层残余物的形成过程进行了研究,以此来研究碳质炭渣与阻燃性能的关系。结果表明：PA6／OMMT纳米复合材料在燃烧过程中,逐渐形成了由皮层和峰窝状的窝层构成的皮一窝炭层结构,皮层和窝层的骨架都是由纳米尺度的炭层片层组成的;皮层比较致密但较薄,隔气效果较好;窝层合有大量尺寸较大的空欠结构。隔气效果不如皮层,但整体上增大了炭层的体积．隔热效果较好;皮层和窝层的组合有很好的阻隔功能．对复合材料起到阻燃作用。     

PBA/OMMT制备及其对PA6力学性能的影响

用十二烷基磺酸钠(SDS)将Na基蒙脱土(MMT)改性成有机蒙脱土(OMMT),采用原位聚合法制备了聚丙烯酸丁酯(PBA)/OMMT,并将其按适当比例添加到尼龙6(PA6)中。通过红外光谱仪、差示扫描量热仪等表征了OMMT、PBA/OMMT的结构,并检测了PA6/PBA/OMMT复合材料的力学性能。结果表明:添加5%的PBA/OMMT后,PA6/PBA/OMMT复合材料的拉伸强度提高了23.1%,缺口冲击强度的降低幅度有所减缓。     

SEBS/蒙脱土纳米复合材料结构和性能研究

采用溶液混合方法制备了氢化苯乙烯/丁二烯三元嵌段共聚物(SEBS)/有机蒙脱土(OM-MT)纳米复合材料(NC)。对SEBS/OMMT NC的插层结构和物理力学、动态力学、耐热等性能进行了研究。结果表明,与SEBS复合,OMMT层间距明显增大,制备出具有插层型结构的NC。加入OMMT可明显提高SEBS的拉伸断裂强度、300%定伸强度和断裂伸长率,但永久变形也增大。DMA研究表明,SEBS/OMMT NC的储能模量和损耗模量比纯SEBS显著提高,PEB链段的tanδ降低,而PS链段增加。SEBS/OMMT NC比SEBS的热稳定性明显提高。     

Microstructure, nucleation and thermal properties of high-pressure crystallized MWCNT/nylon-6 composites

Multi-wall carbon nanotube (MWCNT)/nylon-6 composites made by in-situ polymerization and subsequently modified by treatment at 1.0 GPa (or 1.7 GPa) and 530 K have been studied by WAXD, DSC and NMR. The pressure treatment gives an amorphous to crystalline transformation where the crystallinity increases from ∼31% to as much as ∼58% concurrently as the nylon-6 crystals increase in size and attain a preferred orientation relative to the applied pressure. A composite of 2.1 wt% purified MWCNT in nylon-6 shows significantly higher melting temperature than neat nylon-6 after identical pressure treatments. The improved thermal stability of the composite is attributed to crystal growth in the presence of reinforcing MWCNTs. The NMR spectrum of a pressure treated composite is similar to that of nylon-6 single crystals, which suggests a reduction of crystal boundaries after treatment, but there is no indication of covalent bonds between the nylon-6 chains and the MWCNTs.     

RIM-pultrusion of nylon-6 and rubber-toughened nylon-6 composites

Unidirectionally reinforced thermoplastic composites of Nylon-6 and polypropylene oxide-Nylon-6 block copolymers have been prepared by the reaction injection molding (RIM)-pultrusion process. This process takes advantage of both the RIM and the pultrusion techniques, while avoiding their inherent shortcomings. It also represents a novel way of incorporating toughening rubber domains into a thermoplastic composite. The composites produced exhibit excellent mechanical integrity with essentially zero void content. The chemical and physical states of the composites produced by the process were probed in terms of mechanical relaxation behavior using a dynamic mechanical spectrometer. Due to the simultaneous occurrence of both polymerization and crystallization processes in the reacting system, the resulting material is in a thermodynamically nonequilibrium state. An annealing effect is shown to correspond structurally to an increase in matrix crystallinity and the degree of phase separation, Izod impact tests were used to compare Nylon-6 and rubber-toughened Nylon-6 RIM-pultruded composites. The potential of secondary processing was, demonstrated by compression molding of the RIM-pultruded composite rods.     

球磨法制备POE-g-MAH/OMMT增韧母粒及其对PA6增韧改性

通过球磨法制备马来酸酐接枝(乙烯-辛烯)共聚物(POE-g-MAH)／有机化蒙脱土(OMMT)增韧母粒,并将其用于尼龙(PA)6的增韧改性.结果表明,球磨法制备的POE-g-MAH/OMMT增韧母粒尺寸比较均匀,有少量POE-g-MAH进入OM MT片层之间,导致OMMT片层间距有所增加.POE-g-MAH/OMMT增...     

纳米氧化锌改性PA6复合材料的制备及性能研究

利用熔融共混法制得了纳米氧化锌改性PA6复合材料,并研究了其有关性质。结果表明:纳米氧化锌能有效改善PA6的力学性能,其添加量在3%时材料力学性能最佳。结晶及热分析研究表明纳米粒子能有效限制PA6分子链段运动,使其结晶度下降。     

Microstructures and mechanical properties of polypropylene/polyamide 6/polyethelene-octene elastomer blends

A series of polymer blends were designed and manufactured. They are composed of three phases: polypropylene (PP), polyamide-6 (PA6) and polyethylene-octene elastomer (POE) grafted with maleic anhydride. The weight fraction of PA6 was adjusted from 0 to 40% by increments of 10%, and the weight fraction of POE was systematically half that of PA6. The morphology, essentially made of PA6 particles dispersed in the PP matrix, was characterised by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the extruded plates prepared with the blends, the shape of the dispersed PA6 particles showed an elongated ellipsoidal shape, whose aspect ratio increased somehow with alloying content. The POE modifier was observed both as a thin interlayer (less than 100 nm thickness) at the PP/PA6 interface, and as a few isolated particles. The elastic modulus and yield stress in tension are nearly constant for PP and blends. By contrast, the notched Izod impact strength increases very much with alloying content. This remarkable effect is interpreted in terms of POE interphase cavitation, enhanced plastic shear deformation and resistance of PA6 particles to crack propagation.