高性能聚乙烯纳米复合材料的研究

发布时间：2018-05-09 13:39

本文选题：高密度聚乙烯 + 热塑性弹性体　；参考：《青岛科技大学》2015年硕士论文

【摘要】：本文使用不同方法改性制得的高性能蒙脱土(MMD对高密度聚乙烯(HDPE)进行改性,采用双螺杆熔融挤出方法制备了高密度聚乙烯纳米复合材料,在得到高强度纳米复合材料的同时为弥补韧性的损失,加入了新型热塑性聚烯烃弹性体(POE)对其增韧改性,最后选用热塑性弹性体接枝马来酸酐(POE-g-MAH)作为相容剂增强无机纳米填料与聚合物之间的作用,获得高性能高密度乙烯纳米复合材料。采用力学性能测试仪、氧指数测定仪、DSC、TGA、SEM、TEM、XRD等对力学性能、阻燃性能、结晶性能、热稳定性、内部结构、纳米蒙脱土层间距等方面性能进行测定分析,以结构决定性能为方向,制备高性能材料。HDPE/MMT复合材料测试结果表明：蒙脱土添加质量分数为5phr时,纳米复合材料拉伸强度和弯曲强度最高且B.OMMT复合材料性能优于A.OMMT复合材料,但是冲击强度随着蒙脱土添加分数增多而降低,且降低趋势很大。两种MMT对纳米复合材料均有一定的阻燃效果,随着添加分数的增加,氧指数随之上升,B.OMMT的上升趋势快于A.OMMT。同时B.OMMT是良好的成碳剂,复合材料燃烧后不滑落,燃烧形态较好,阻燃效果优于A.OMMT。XRD测试表明两种MMT层间距增大,B.OMMT层间距明显大于A.OMMT, B.OMMT中有部分峰消失形成了部分剥离结构。描电镜分析表明,B.OMMT (5phr)复合材料相界面相对模糊,当添加量继续增大时,大量蒙脱土发生团聚。DSC测试表明两种蒙脱土降低了复合材料的结晶度,B.OMMT的影响相对较小,同时添加量对复合材料的熔点基本无影响。TG测试表明,蒙脱土增强了复合材料的耐热性,B.OMMT效果优于A.OMMT。通过TEM测试分析发现,纳米复合材料形成插层结构,部分形成剥离结构。HDPE/POE体系结果表明：POE用量增大,体系拉伸强度、弯曲强度逐渐降低,冲击强度增大,断裂伸长率增大,综合各因素影响,选择最佳质量分数为10phr。HDPE/POE/OMMT体系中,OMMT用量增大,体系拉伸强度升高,冲击强度先增大后减小,选择最佳添加质量分数为5phr; DSC测试结果表明,MMT降低体系的结晶度,对体系的熔点基本没有影响；TGA测试表明,蒙脱土的加入可以提高复合材料的热稳定性。SEM测试分析表明,OMMT质量分数为5phr时,OMMT的团聚现象不明显,在体系中的分散效果较好。TEM测试分析表明,OMMT(5phr)在体系中的分散较好,体系中出现插层架构。HDPE/MMT/POE-g-MAH体系结果表明：挤出工艺(剪切温度、主机转速)对体系性能有一定影响,剪切温度方面：剪切温度升高,拉伸强度、弯曲强度、冲击强度均减小,因而最佳温度选择185℃；转速方面：主机转速提高,材料的力学性能整体下降,最佳转速为80rpm。固定POE-g-MAH用量不变,MMT用量增大,体系拉伸强度升高,冲击强度先增大后减小,选择MMT最佳用量为5份。固定MMT用量,POE-g-MAH的用量增大,体系的拉伸强度先增加后减小,冲击强度一直增大,弯曲强度减小,断裂伸长率增大,综合结果分析得出最佳添加质量分数为10份。根据热重分析测试表明,蒙脱土热分解温度整体提高,体系的耐热性提高,根据DSC分析测试表明,蒙脱土的加入,降低了体系的结晶性能,对体系的熔点基本没有影响。通过SEM测试分析表明,POE-g-MAH加入到体系后,两相之间的相界面模糊,相容性变好。通过TEM测试分析表明,POE-g-MAH加入到体系后,蒙脱土在体系中分布均匀,片层发生扭曲变形,有单片层出现说明体系出现了剥离结构。
[Abstract]:In this paper, the high density polyethylene (HDPE) modified by MMD was modified by different methods. The high density polyethylene nanocomposites were prepared by the twin screw melt extrusion method. The new thermoplastic polyolefin elastomer (POE) was added to the high strength nanocomposites to compensate for the toughness loss. Toughened and modified, the thermoplastic elastomer grafted maleic anhydride (POE-g-MAH) was used as a compatibilizer to enhance the role of inorganic nano filler and polymer, and high performance and high density ethylene nanocomposites were obtained. Mechanical properties, DSC, TGA, SEM, TEM, XRD, etc. were used for mechanical properties, flame retardancy and crystallization. Properties, thermal stability, internal structure, and nanoscale interlayer spacing are measured and analyzed. The structure determines the performance direction. The test results of high performance material.HDPE/MMT composites show that the tensile strength and bending strength of the nanocomposites are the highest and the B.OMMT composite material is 5phr when the montmorillonite is added to the mass fraction. It can be better than A.OMMT composite, but the impact strength decreases with the increase of the addition fraction of montmorillonite, and the decrease trend is great. Two kinds of MMT have a certain flame retardant effect on nanocomposites. With the increase of addition fraction, the oxygen index rises, the rising trend of B.OMMT is faster than A.OMMT. and B.OMMT is a good carbon forming agent. After burning, the combustion shape is better and the flame retardant effect is better than A.OMMT.XRD test, which shows that the spacing of two kinds of MMT layers increases, the spacing of B.OMMT layer is obviously greater than A.OMMT, and some peaks in B.OMMT disappear to form part of the peeling structure. The.DSC test showed that two kinds of montmorillonite decreased the crystallinity of the composite. The effect of B.OMMT was relatively small, and the addition amount had no effect on the melting point of the composite. The.TG test showed that the montmorillonite enhanced the heat resistance of the composite. The effect of B.OMMT was better than that of A.OMMT. by TEM test analysis. The result of.HDPE/POE system with intercalation structure and partial formation of peeling structure shows that the amount of POE increases, the tensile strength of the system, the bending strength decrease gradually, the impact strength increases, the elongation at break increases, and the optimum mass fraction is influenced by various factors, and the amount of OMMT is increased, the tensile strength of the system is increased, and the impact of the system is increased. The strength first increases and then decreases, and the optimum addition mass fraction is 5phr. The results of DSC test show that the crystallinity of the system has no effect on the melting point of the system. The TGA test shows that the addition of montmorillonite can improve the thermal stability of the composite material by.SEM test and analysis. When the mass fraction of OMMT is 5phr, the aggregation phenomenon of OMMT is not. It is obvious that the dispersion effect in the system is better.TEM test analysis shows that the dispersion of OMMT (5phr) in the system is better. The result of the intercalation structure.HDPE/MMT/POE-g-MAH system in the system shows that the extrusion process (shear temperature, main engine speed) has a certain influence on the system performance, shear temperature, the shear temperature, tensile strength, bending. Strength and impact strength decreased, so the optimum temperature was chosen at 185. As the speed of the engine increased, the mechanical properties of the material decreased, the optimum speed was 80rpm. fixed POE-g-MAH, the amount of MMT increased, the tensile strength of the system increased, the impact strength increased first and then decreased, and the optimum amount of MMT was selected as the fixed MMT dosage, POE. When the amount of -g-MAH increased, the tensile strength of the system increased first and then decreased, the impact strength increased, the bending strength decreased and the elongation at break increased. According to the comprehensive results, the optimum addition mass fraction was 10 copies. According to the thermogravimetric analysis, the thermal decomposition temperature of the montmorillonite was improved, the heat resistance of the system was improved, and the test was based on the DSC analysis. The results show that the addition of montmorillonite reduces the crystallization of the system and has no effect on the melting point of the system. The SEM test analysis shows that the phase interface between the two phases is blurred and the compatibility becomes better after the addition of POE-g-MAH to the system. The TEM test analysis shows that the montmorillonite is distributed evenly in the system and the lamellar occurs after the POE-g-MAH is added to the system. There is a single layer of distortion, indicating that there is a peeling structure.

【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ325.12;TB33

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