尼龙6/SiO_2纳米复合材料的制备及其力学性能和热稳定性

以表面含有氨基的可反应性纳米SiO2(RNS-A)和表面含有烷基碳链的可分散性纳米SiO2(DNS-3)作为填料,利用原位聚合法制备了尼龙6/SiO2纳米复合材料(相应的复合材料分别简记为RPA和DP3);采用透射电子显微镜观察了复合材料中纳米SiO2的表面形貌,并利用热失重分析仪测定了复合材料的热稳定性,进而考察了纳米SiO2表面功能基团对尼龙6力学性能和热稳定性的影响.结果显示,纳米SiO2能够很好地分散在尼龙6基体中,并使尼龙6的热分解温度提高10℃左右.与此同时,RPA的最大拉伸强度和冲击强度较纯尼龙6的分别提高34.5%和12.5%,DP3的最大拉伸强度和冲击强度分别提高18.2%和45.7%.这表明两种纳米SiO2均可以有效地提高尼龙6的力学性能和热稳定性;可以推测,纳米SiO2的增强效应与其在尼龙6基体材料中的分散和界面作用有关.     

纳米硅粉/MC尼龙6复合材料的制备与性能

将纳米硅粉分散于熔融的己内酰胺中,以NaOH为催化剂,2,4-甲苯二异氰酸酯为助催化剂,原位制备了纳米硅粉/MC尼龙6复合材料.用红外光谱、X射线衍射、场发射扫描电镜、热重分析仪和差示扫描量热仪对复合材料的界面结构和性能进行了研究.结果表明,纳米硅粉在尼龙6基体中具有较好的分散性,而且其与基体有比较强的界面作用,纳米硅粉促进了尼龙6的结晶,但是其对尼龙6的晶型结构没有产生明显的影响.     

ZnO/PPy异质纳米复合材料的制备、表征及其气敏特性

室温下, 采用原位聚合法, 以吡咯(PY)为单体, 氯化铁(FeCl₃·6H₂O)为氧化剂, 在塑料基片上聚合生长了聚吡咯(PPy)纳米微球. 然后在聚吡咯基片上生长ZnO种子, 将表面种有ZnO种子的PPy元件置于六次甲基四胺与硝酸锌的混合溶液中, 90 ℃水浴中, 在PPy微球上生长了ZnO纳米棒, 合成了PPy/ZnO异质纳米复合材料. 分别通过X射线衍射仪(XRD)和场发射扫描电镜(FESEM)对PPy/ZnO异质纳米复合材料的结构和形貌进行了表征. 制备了塑料基的PPy/ZnO异质纳米复合材料气体传感器, 在室温下, 对10×10^-6-150×10^-6 (体积分数)浓度范围的氨气进行了气敏测试, PPy/ZnO气敏元件对氨气响应的灵敏度基本呈线性关系, 且对甲醇、丙酮、甲苯等有机气体表现出很好的选择性. 最后, 对PPy/ZnO异质纳米复合材料的形成机理进行了简要分析.     

MC尼龙-纳米La2O3复合材料的制备及性能研究

用原位分散聚合法制备了一系列MC尼龙／纳米La2O3复合材料，研究了纳米La2O3用量对复合材料力学性能的影响，用SEM观察了La2O3粒子在MC尼龙基体中的分散情况，用XRD对复合材料的晶体结构进行了表征。SEM观察结果表明，当纳米La2O3用量小于1％时，纳米La2O3均匀分散于MC尼龙基体中，团聚情况很少，当纳米La2O3用量大于1％时，纳米La2O3开始团聚；XRD研究结果表明，纳米La2O3没有改变MC尼龙的结晶形态；力学性能的研究结果表明，随着纳米La2O3用量的增加，复合材料的拉伸强度、断裂伸长率、缺口冲击强度、弯曲强度和弯曲模量都呈先升后降的趋势，当纳米La2O3用量为0．5％时，复合材料的拉伸强度和断裂伸长率达到最大值，分别比MC尼龙提高17．9％和52．1％，当纳米La2O3的用量为1．0％时，复合材料的缺口冲击强度、弯曲强度和弯曲模量达到最大值，分别比MC尼龙基体提高36，6％．12．7％和16．3％。     

离子液体中ZnO纳米棒的制备与表征

离子液体中ZnO纳米棒的制备与表征;离子液体;ZnO纳米棒;热分解     

CMC辅助纳米ZnO粒子的制备及表征

以离子型纤维素醚羧甲基纤维素(CMC)的水溶液为反应介质,制备[Zn4CO3(OH)6]CMC水凝胶,洗涤、干燥后经不同温度煅烧前驱物得到ZnO纳米粒子。通过XRD、SEM、TEM、TG-DSC及FT-IR等测试技术对产物的组成、粒径及形态进行表征,研究了CMC对前驱物及ZnO形态和尺寸的影响。结果表明,由于CMC加入对煅烧前驱物产生的空间位阻作用,所制得纳米ZnO粒子粒度分布均匀、分散性好、不易团聚、粒子的平均粒径<20 nm。利用UV-V is测试了纳米ZnO的光吸收性能,所得的纳米ZnO在200~400 nm具有较强的吸收性。     

尼龙6/石墨纳米导电复合材料的制备与性能

通过原位插层聚合制备了尼龙 6 /石墨纳米导电复合材料 ,其室温导电渗滤阈值为 =0 75vol% ,远远低于常规导电粒子填充的聚合物复合材料 .当石墨体积分数为 2 0vol%时 ,室温电导率可达 10 -4 S/cm .透射电镜研究表明 :由于石墨经高温膨胀后其片层被剥离导致了片状石墨粒子具有巨大的径厚比 ,经原位插层聚合其片层厚度进一步被剥离为几十个纳米 ,同时原位插层聚合使得石墨粒子能够均匀分散在尼龙 6基体中 ,因而导致了该导电复合材料的低渗滤阈值和高导电性能 .     

熔体插层制备尼龙6/蒙脱土纳米复合材料的性能表征

通过熔体插层成功地制备了尼龙６／蒙脱土纳米复合材料，测试了力学性能、耐热性能和耐溶剂性．通过ＴＥＭ、ＷＡＸＤ、ＤＳＣ等手段，研究了结构与结晶行为，并与插层聚合的尼龙６／蒙脱土纳米复合材料进行了对比．实验表明通过熔体插层可使尼龙６基体插层于蒙脱土中，所得到的复合物的性能较尼龙６有很大提高，且与插层聚合的尼龙６／蒙脱土纳米复合材料的性能相当．     

碳纳米管/ZnO纳米复合体的制备和表征

通过将不同直径的ZnO纳米颗粒与碳纳米管连接制备了碳纳米管/ZnO纳米复合体. 将团聚的ZnO纳米颗粒分散并用表面活性剂CTAB使纳米颗粒带正电. 化学氧化碳纳米管使其带负电. ZnO/CTAB微团通过碳管表面羧基与CTAB的静电作用与碳纳米管连接形成纳米复合体. 研究了复合体形成的不同实验条件, 表征了碳纳米管/ZnO纳米复合体的结构并研究了纳米复合体的光学特性. 研究表明, 与碳纳米管连接的ZnO纳米颗粒是互不连接的并保持量子点的特性. 光致发光研究表明ZnO纳米颗粒的激发在纳米复合体中有淬灭.     

尼龙6/蒙脱土纳米复合材料的制备、结构与力学性能的研究

未经处理及经１１ 氨基酸处理的蒙脱土由于己内酰胺的引入而发生膨胀．己内酰氨可以在蒙脱土的硅酸盐片层间聚合，形成尼龙６／蒙脱土纳米复合材料．经１１ 氨基酸处理的蒙脱土和尼龙６分子间有很强的化学相互作用．与未经处理的蒙脱土相比，其所构成的纳米复合材料具有很好的力学性能．     

用反应挤出法制备尼龙6塑料

利用双螺杆挤出机进行了尼龙６阴离子开环聚合反应的研究，通过改变引发剂及活化剂的浓度、螺杆转速、机筒的温度分布以及螺杆元件构型的排布等，研究这些工艺参数对尼龙６反应挤出产物性能的影响。结果表明，反应挤出的尼龙６综合机械性能比水解缩聚法生产，且具有较高的性能价格比。     

Preparation and characterization of nylon 66/montmorillonite nanocomposites with co-treated montmorillonites

In this paper, a new type of organophilic montmorillonites, co-treated by octadecylammonium and aminoundecanoic acid, were synthesized and applied to prepare nylon 66/montmorillonite nanocomposites via melt compounding in a twin extruder. WAXD and TEM characterization indicate that a disordered structure was derived and the montmorillonite platelets dispersed in nanoscale in the nylon 66 matrix. The nanocomposites with co-treated montmorillonite display comparatively higher strength and modulus compared to nylon 66 matrix.     

固相缩聚法制备高粘度尼龙1111

采用固相缩聚工艺提高尼龙1111的相对粘度,是制备高粘度尼龙1111的有效方法之一。固相后缩聚法制备相对粘度高于2.5的高粘度尼龙1111,宜选择初始相对粘度为2.0的尼龙1111,反应时间12h,反应温度175℃。增粘后的尼龙1111具有更为优良的物理机械性能。     

分子筛增强增韧MC尼龙的研究

简介了MC尼龙作为工程塑料的优缺点,提出了对其在实际应用中的改性要求,以无机刚性粒子改性聚合物机理为背景,结合分子筛独特的结构特点及其当前在聚合物中的应用,并根据实验实践,首次提出了分子筛增强增韧MC尼龙一系列的模型及机理,并展望了分子筛改性整个聚合物体系的美好前景。     

PC/尼龙6共混合金的结晶结构与性能

聚碳酸酯(PC)由于具有突出的冲击韧性、良好的透明性、尺寸稳定性和电气绝缘性而广泛应用于电子电气、仪器仪表、汽车、机械、医疗、照明和建筑等领域,是一种综合性能优良的工程塑料.但也存在着加工流动性差和耐药性差、易应力开裂及对缺口敏感等缺陷,且价格昂贵,因而限制了它的应用范围.对PC进行合金化,提高PC的性能,降低成本是PC改性的重要研究方向,开发成功的PC合金有PC/ABS,PC/PET,PC/PBT[1]和PC/PE[2]等.制备高性能PC/尼龙6(PA6)合金是目前国内外PC改性的热点.PA6的加入可以改善PC的耐药性、耐应力开裂性及加工性能,降…     

Preparation and characterization of polymer/silica nanocomposites via double in situ miniemulsion polymerization

Polymer/SiO₂ nanocomposite microspheres were prepared by double in situ miniemulsion polymerization in the presence of methyl methacrylate, butyl acrylate, γ‐methacryloxy(propyl) trimethoxysilane, and tetraethoxysilane (TEOS). By taking full advantage of phase separation between the growing polymer particles and TEOS, inorganic/polymer microspheres were fabricated successfully in a one‐step process with the formation of SiO₂ particles and the polymerization of organic monomers taking place simultaneously. The morphology of nanocomposite microspheres and the microstructure, mechanical properties, thermal properties, and optical properties of the nanocomposite films were characterized and discussed. The results showed that hybrid microspheres had a raspberry‐like structure with silica nanoparticles on the shells of polymer. The silica particles of about 20 nm were highly dispersed within the nanocomposite films without aggregations. The transmittance of nanocomposite film was comparable to that of the copolymer film at around 70–80% from 400 to 800 nm. The mechanical properties and the fire‐retardant behavior of the polymer matrix were improved by the incorporation of silica nanoparticles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3128–3134, 2010     

Thermal properties and combustion characterization of nylon 6/MgAl-LDH nanocomposites via organic modification and melt intercalation

The nylon 6/MgAl layered double hydroxide (MgAl-LDH) nanocomposites have been prepared by melt intercalation of nylon 6 into the part organic dodecyl sulfate (DS) anion-modified MgAl(H-DS) interlayers. The structures and properties of MgAl(H-DS) and corresponding nanocomposites were characterized by ion chromotography, X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), and cone calorimeter test (CCT). The nanoscale dispersion of MgAl(H-DS) layers in the nylon 6 matrix has been verified by the disappearance of d₀₀₁ XRD diffraction peak of MgAl(H-DS) and the observation of TEM image. DSC tests evince that these exfoliated MgAl(H-DS) layers play the role of nucleating agents with strong heterogeneous nucleation effect on the crystallization of nylon 6 and increase its crystallization temperature over 12 °C with only 5 wt% MgAl(H-DS). TGA tests show that the effect of alkaline catalysis degradation from LDH on nylon 6 decreases the thermal stability of nylon 6/MgAl-LDH nanocomposites. The data from the cone calorimeter tests show that the HRR and MLR values of the sample with 5 wt% MgAl(H-DS) decrease considerably to 664 kW/m² and 0.161 g/m² s from 1064 kW/m² and 0.252 g/m² s of pure nylon 6, respectively. This kind of exfoliated nanocomposite is promising for the application of flame-retardant polymeric materials.     

Structural investigation of polyaniline/Nylon 6 blends by small-angle neutron scattering and small- and wide-angle X-ray scattering

The structure of blends of Nylon 6 with deuterated polyaniline emeraldine base (D-PANI-EB) and fully doped D-PANI salts (D-PANI-ES) formed from camphorsulfonic acid (CSA), methanesulfonic acid (MSA), or dodecyl benzenesulfonic acid (DBSA) were investigated by small-angle neutron (SANS) and X-ray scattering. The blends were formed from hexafluoro-2-propanol solutions and had volume fractions of 0.038, 0.20, and 0.40 for D-PANI/CSA, 0.20 and 0.40 for D-PANI/MSA, 0.24 and 0.44 for D-PANI/DBSA, and 0.07, 0.14, and 0.31 for D-PANI-EB. The SANS results are compared with a number of standard models for two-phase systems. No evidence was found for significant molecular mixing. In some cases the inverse power law model is in reasonable agreement with observations, and in the case of the lowest concentration of D-PANI/CSA there is an indication of mass fractal structure. This was not found at the higher concentrations. The results establish that the blends with the smaller more polar dopants CSA and MSA behave similarly and are unlike either the D-PANI/DBSA blends or those with D-PANI-EB. There is evidence that the simple picture of two pure phases is inadequate for these materials. With the exception of the D-PANI/DBSA blend which has a relatively low scattering contrast, the results indicate that the lower limit of volume fraction for application of SANS is a few percent D-PANI-ES in Nylon 6. X-ray scattering was used to demonstrate the presence of Nylon 6 lamellae and residual peaks attributable to the pure components. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2765–2774, 1997     

尼龙1010电镜试样的制备

考察了尼龙１０１０结晶试样进行ＳＥＭ观察时合适的溶剂刻蚀条件。在甲酸蒸气中，于室温刻蚀４０分钟以上，或于６０～８０℃刻蚀２０～４０分钟时能得到较好的刻蚀效果。     

Preparation and characterization of polypropylene/mesoporous silica nanocomposites with confined polypropylene

Polypropylene (PP)/Ti-MCM-41 nanocomposites were prepared by isospecific propylene polymerization with Ti-MCM-41/Al(i-C₄H₉)₃ catalyst. The cross polarization/magic angle spinning (CP/MAS) ¹³C NMR spectrum of the composite was similar to that of the conventional isotactic PP, and the decrease in the pore volume of Ti-MCM-41 in the nanocomposites, as measured by N₂ adsorption, was consistent with the value calculated from the weight loss in the thermogravimetric analysis (TGA) curve; both these facts attest to propylene polymerization within the mesopores of Ti-MCM-41. Alkali treatment followed by extraction with o-dichlorobenzene allows us to extract the confined PP out of the Ti-MCM-41 mesopores. Although the PP/Ti-MCM-41 nanocomposites do not exhibit a crystalline melting point, the same PP when extracted from the mesopores showed a clear melting point at 154.7 °C; this indicates that the crystallization of PP confined in mesopores is strongly hindered. For the PP polymerized within the confinement, the molecular weight (M_w) and molecular weight distribution (M_w/M_n) were 84,000 and 4.3, respectively; these values were considerably smaller than those of the PP polymerized concurrently outside the Ti-MCM-41 mesopores (M_w = 200,000–450,000, M_w/M_n = 40–75). Therefore, the confinement also has a marked effect on the molecular weight of the PP. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3324–3332, 2003