【作者】 钱俊；

【导师】 许湧深；

【作者基本信息】 天津大学 ， 材料化学工程， 2011， 博士

【摘要】 聚合物基无机纳米复合材料在材料制备和性能领域备受关注,对其的研究具有重要的意义,而聚丙烯（PP）和二氧化硅（SiO₂）是目前应用较为广泛的两种基础原料。本文借助超声、辐射、非水溶胶-凝胶（Sol-gel）等一系列新型方法和手段,成功制备了四种PP/SiO₂纳米复合材料,使其综合性能得到大大改善。首先研究了马来酸酐（MAH）对聚丙烯蜡（PPw）的接枝改性,分别采用熔融超声接枝、悬浮超声接枝、预辐射-溶液接枝和悬浮体系共辐射接枝四种方法成功制备了接枝产物PPw-g-MAH,采用有机碱四丁基氢氧化铵（TBAOH）乙醇溶液滴定的方法测定了MAH的接枝率（G）。考察了超声强度、辐射总剂量、MAH含量、反应温度与反应时间等对G值的影响,考察了第二单体苯乙烯（St）、给电子体、自由基引发剂和阻聚剂等对G值的影响,并采用FTIR、¹³C NMR、DSC、XRD等手段对产物进行了表征。结果表明,超声和辐射均能引发MAH对PPw的接枝反应,且辐射接枝法所得产物的G值高于超声接枝法;悬浮体系共辐射接枝法可得MAH的最大G值为2.67%,在St参与下则能达到3.40%。其次采用SiO₂纳米粉体路线成功制备了PP/PPw-g-MAH/SiO₂纳米复合材料和PP/PPw-g-MAH/SiO₂-g-KH560（γ-缩水甘油醚氧丙基三甲氧基硅烷）纳米复合材料,并借助FTIR、DSC、XRD、POM、SEM、力学性能等测试手段对复合材料进行了表征。结果表明,纳米SiO₂在材料中分散良好,有机-无机界面相容性和粘结力强,复合材料综合性能得到提高;相容剂PPw-g-MAH的加入起到了一定的增容作用,增强了两相粘结力;KH560的加入,有效地改性了纳米SiO₂,并与接枝的MAH键合增强了SiO₂和PPw的粘结力,提高了界面相容性,从而有效地改善纳米复合材料的性能。最后采用SiO₂溶胶路线成功制备了PP/乙丙橡胶（ EPR ）-g-MAH/SiO₂-g-KH560纳米复合材料和PP/PPw-g-KH570（γ-甲基丙烯酰氧丙基三甲氧基硅烷）/SiO₂纳米复合材料。为此,首先研究了正硅酸乙酯（TEOS）-甲酸的二元非水Sol-gel反应,借助表观现象目测、UV吸光度法、电导率法及旋转粘度法简便地考察了非水Sol-gel反应的前期动力学过程,并研究了非水Sol-gel反应的影响因素。随后考察了这两种复合材料的制备工艺,并采用FTIR、DSC、SEM、TGA、力学性能等测试手段对复合材料进行了表征。结果表明,纳米复合材料中SiO₂与PP间由于有机中间层和化学键合的作用,SiO₂的分散性和相容性好,界面粘结力强,使得复合材料获得优异的综合性能。更多还原

【Abstract】 Polymeric inorganic nanocomposites have received considerable attention in the field of material preparation and properties,and the researches on them have great significance. Polypropylene （PP） and silica （SiO₂） both are widely used basic raw materials now. In this paper, four kinds of PP/SiO₂ nanocomposites were successfully prepared by novel methods of ultrasonication, irradiation, non-aqueous Sol-gel and so on, achieving improved performance.First, the grafting modification of maleic anhydride （MAH） onto PP wax （PPw） was studied. Grafted product PPw-g-MAH was successfully prepared by four methods respectively: ultrasonication in melt or suspension state, pre-irradiation in solution state and co-irradiation in suspension state. The graft degree （G） of MAH was determined by titration using a solution of organic base tetra-butyl ammonium hydroxide （TBAOH） in ethanol. The effects of ultrasonic intensity, total irradiation dose, MAH content, reaction temperature and reaction time on G value were investigated, and the effects of the second monomer styrene （St）, electron donor, free radical initiator and inhibitor on G value were also researched. The products were characterized by FTIR, ¹³C NMR, DSC, XRD and so on. The results showed that the grafting reaction of MAH onto PPw could be induced by ultrasonication and irradiation, and the G value obtained in irradiation method was higher than that in ultrasonication method. The highest G value of 2.67% was achieved by method of co-irradiation in suspension state, and 3.40% could be reached with the aid of St.Second, PP/PPw-g-MAH/SiO₂-g-KH560 （3-glycidyloxypropyltrimethoxysilane） nanocomposites and PP/PPw-g-MAH/SiO₂ nanocomposites were successfully prepared by route of SiO₂ nanopowders. The composites were characterized by FTIR, DSC, XRD, POM, SEM, mechanical properties and so on. The results showed that the nano-SiO₂ was dispersed well in composites and the organic-inorganic interfacial compatibility and bonding were strong, obtaining good material performance; the added PPw-g-MAH played a certain role as a compatilizer, increasing the organic-inorganic interfacial bonding; the added KH560 effectively modified the nano-SiO₂ and reacted with the grafted MAH, increasing the adhesive force between SiO₂ and PPw and interfacial compatibility, resulting the improved material performance.Finally, PP/ethylene-propylene rubber （EPR） -g-MAH/SiO₂-g-KH560 nanocomposites and PP/PPw-g-KH570 （γ-methacryloxypropyltrimethoxysilane） /SiO₂ nanocomposites were successfully prepared by route of SiO₂ Sol. For this, the binary non-aqueous Sol-gel reaction of tetraethoxysilane （TEOS）-formic acid was researched first. The non-aqueous Sol-gel reaction kinetics in earlier stage was simply investigated by apparent visual phenomena, UV absorption spectrophotometry, electrical conductivity and rotation viscometry, and the influential factors on non-aqueous Sol-gel reaction were researched. Then the preparation technologies for these two composites were studied, and characterizations were carried out, such as FTIR, DSC, SEM, TGA, mechanical properties and so on. The results showed that the SiO₂ in nanocomposites had good dispersion, well compatibility and strong interfacial bonding with the aid of organic interlayer and chemical bonding between SiO₂ and PP, making the composites having improved performance.更多还原