【作者】 王建华；

【导师】 唐薰； 熊远凡；

【作者基本信息】 湖南大学 ， 化学工程， 2004， 硕士

【摘要】 聚合物／粘土纳米复合材料既表现出粘土矿物优良的强度、尺寸稳定性和热稳定性，又具有聚合物的断裂性能、可加工性和良好的塑性。 本文研究了用一步插层原位聚合法制备聚酰胺6(PA6)／粘土纳米复合材料的工艺条件，对所合成的复合材料的性能进行了详细地表征。实验中选用阳离子交换能力为90～120mmol／100g、蒙脱土含量≥60％的粘土。通过对粘土处理前后的红外和XRD分析可知处理土中有强烈的亚甲基伸缩振动特征峰，表明粘土层间已插入有机化合物而成为了有机化粘土。通过使用水和助分散剂D对粘土进行处理后，以C为主有机化剂、以B为辅助有机化剂，A为质子化剂，可通过机械除水法除水90％以上。采用插层原位聚合技术于250～260℃常压聚合2～6小时，减压反应15～30分钟，不需加聚合催化剂。 PA6／粘土纳米复合材料是以γ型结晶为主的PA6，说明纳米粘土的加入使得聚合物的晶型发生了变化。制备的复合材料中粘土己剥离成纳米尺度并均匀分散在PA6基体中。该材料的DSC升温曲线具有熔融双峰，说明粘土在PA6中促进γ晶型生成的作用。而降温曲线表明粘土加入使得PA6的结晶温度提高，过冷度变小，结晶峰宽变窄，结晶度增大，说明粘土对于PA6的结晶起到了异相成核作用，从而提高了PA6结晶速率。力学性能测试结果表明纳米PA6比纯PA6有明显的提高。纳米PA6和纯PA6的流变行为表明它们都属于假塑性流体，前者的非牛顿指数小于后者，前者的表观粘度小于后者。粘土的加入使材料对氧气的透过率和吸水率降低，表明粘土的加入大大提高了材料的阻隔性能，同时还具有较好的阻燃效果。 本文还简介了纳米PA6在注塑制品、薄膜、纤维丝等方面的应用前景。更多还原

【Abstract】 In this paper, the processing conditions of preparing polyamide-6 / clay nanocomposites by one-step in-situ intercalation polymerization method were studied, and the structure and properties of the nanocomposites were characterized in detail by means of FTIR, XRD, TEM, DSC and TG etc.In order to improve the compatibility between clay and the organic phases, organoclay was synthesized, and changes in the layer structure of clay before and after the intermixing investigated. The cation exchange capacity is 90~120mmol/100g and the content of montmorillonite larger than 60% of clay was chosen in experiment. The clay was treated with using water and auxiliary dispersing agent D, then organoclay was prepared from sodium type clay by cation exchange with protonating agent A, main organizing agent C and auxiliary organizing agent B, which made clay change from hydrophilic to lipophilic, could dewatering more than 90% by the mechanical dewatering method. FTIR analysis before and after of the treated clay showed that exist the line of deformation vibration of -CH2- at 1460cm-1 and the line of stretching vibration of C-H at 2939cm-1 in treated clay. It was indicated that organic compound have been intercalated into clay silicate layers form an organoclay. Spacing of layers of clay was detected using XRD and was observed to have increased from 0.99nm to 1.58nm for organoclay and there is no trace of X-ray diffraction peaks for nanocomposites. The above treated organoclay was mixed with the melted -caprolatam, ?-caprolatam could intercalate into clay interlayer. Subsequently the -caprolatam could polymerize in the organoclay interlayer without catalyst for 2~6h at 250癈 to 260, then vacuum reaction 15~30min.FTIR and XRD experimental results indicated that the crystal form of polyamide-6in nanocomposites was mainly r crystal form. It has been found that the presence ofclay influences the crystal form of polyamide-6 in nanocomposites with increasing of clay content in nanocomposites, the content of y crystal form increased. The XRDpatterns and the TEM images of the nanocomposites showed that the clay layers were exfoliated into nanometer size and dispersed uniformly in the polyamide-6 matrix. Molau experiment indicated that the sample of PA6/clay nanocomposites can suspend stably in formic acid solution. It is found that the affinity between the organoclay and PA6 matrix is very good.The results of XRD and DSC show that the nanocomposites have a crystal structure and crystallization behavior different from that of pure PA6. DSC risingscanning curves show that the nanocomposites have melt double-peak, it was explained that the addition of clay promote y crystal form of PA6 formed. While coolingscanning curves show, with the increment of the clay content in the nanocomposites, that heighten the crystallization temperature of PA6, lost the supercooling degrees, narrowed the width of the crystalline peak, increased the crystalline degrees, decreased crystallization rate parameter K, reduced the crystallization activation energy and half crystallization time of nanocomposites than that of pure PA6. According to the experimental results we conclude that organoclay play the role of iso-phase nucleation in the PA6 matrix, thus enhanced the crystallization rate of PA6 obviously.The results indicated, when compared to the pure PA6, that the thermal stability of nanocomposites was enhanced, decomposition onset temperature was increased slightly, but heat distortion temperature can be greatly improved by addition of low clay loading. Mechanical property testing results indicated that the properties of nanocomposites are superior to those of PA6. This is due to nanoscale effect and the strong interaction between PA6 matrix and clay interface as revealing in XRD, TEM and Molau testing. The rheological behaviors of nanocomposites and PA6 were studied. The results showed that the nanocomposites exhibits similar shear thinning behavior as pure PA6, belonged to pseudoplastic and non-Newtonian fluid, the non-Newtonian index was更多还原