氧化石墨烯与苯基对硅橡胶辐射效应影响的对比研究

发布时间：2018-06-19 21:34

本文选题：硅橡胶 + γ-射线辐照　；参考：《西南科技大学》2017年硕士论文

【摘要】：硅橡胶是一类以重复单元Si-O键为主链,侧链含有有机基团甲基、乙烯基等的高分子材料。因为结构特殊,决定了硅橡胶具有优异的耐高低温性能、电绝缘、耐老化和耐候等优点,已在核工业、宇航工业等方面得到了大量的应用。但是,硅橡胶制品在高能射线的辐射下,会发生性能劣化,影响其使用,所以提高硅橡胶的耐辐照性能具有十分重要的理论意义及实际价值。本文从提高硅橡胶耐辐照性能的两种方法“外保护”和“内保护”入手,分别设计、制备了Si O2-氧化石墨烯(GO)/甲基乙烯基硅橡胶(MVQ)和Si O2/甲基乙烯基苯基硅橡胶(MVPQ)。研究了GO与硅橡胶体系的相容性和GO-Si O2/MVQ的辐照效应,以及苯基对MVPQ辐射效应的影响。考察了GO与硅橡胶基体的相容性以及其在硅橡胶中的分散情况。结果表明,当GO的添加量为2份时,硅橡胶协同补强效果最佳,与只添加Si O2的硅橡胶相比,100%定伸强度提高了37%,拉伸强度提高了17%,断裂伸长率提高了8%,应变扫描起始模量提高了115%。加入GO后,复合材料Payne效应及松弛效应均增大,从另一个角度反映了GO与Si O2共同形成了物理补强效果更佳的填料网络。SEM显示GO可以较均匀的分散在硅橡胶中。在第三章考察了GO与硅橡胶基体的相容性的基础上,研究了GO-Si O2/MVQ的辐射效应。拉伸实验表明,加入GO后,辐照前后硅橡胶的力学性能下降幅度明显减小了,2份为GO最佳的添加量。经受500k Gy的辐射后,只添加Si O2的MVQ的拉伸强度和断裂伸长率分别为3.9Mpa和96%,其拉伸强度和断裂伸长率较辐照前分别下降了30%和77%,2份GO添加的MVQ的拉伸强度和断裂伸长率分别为5.1Mpa和142%,其拉伸强度和断裂伸长率较辐照前分别下降了23%和68%。说明GO可以明显提升硅橡胶的耐辐射性能,这归因于GO对辐照产生的自由基有猝灭作用,以及其良好的气体阻隔性能,可以降低氧对辐照老化的作用,所以具有很好的辐射保护效果。DMA测试表明,辐照后,不同GO添加量的复合材料的应变扫描的起始模量都增大了,说明辐射导致的交联反应占主导地位。2份GO添加的硅橡胶辐照前后储能模量变化最小,说明其受辐射的影响最小,耐辐照性能最好。TGA分析表明,辐照后,GO-Si O2/MVQ的热稳定性均出现不同程度的降低,这是辐照导致硅橡胶分子链降解所致。其中,未加GO的MVQ失重5%的分解温度降低最多。探究了苯基的引入对MVQ辐照效应的影响。结果表明,经受500k Gy的辐射后,不含二苯基的MVQ的拉伸强度和断裂伸长率较辐照前分别降低了30%和77%。10%二苯基含量的MVPQ分别降低了16%和16%。引入苯基后,辐照前后硅橡胶的拉伸强度和断裂伸长率下降幅度变小。随着苯基含量的增加,耐辐射性能先增加,后略有所降低。这归因于苯环的大π键可以分散所吸收的辐射能,但是苯基含量过大,对硫化有阻碍,消弱了化学补强。动态力学测试和松弛实验表明,苯基含量越大,其对辐照交联的阻碍作用越明显。
[Abstract]:Silicone rubber is a kind of polymer material with repeated unit Si-O key and side chain containing organic group methyl and vinyl. Because of its special structure, silicon rubber has excellent properties of high and low temperature resistance, electrical insulation, aging resistance and weathering resistance. It has been widely used in the nuclear industry, aerospace industry and so on. However, silicone rubber has been widely used. It is of great theoretical significance and practical value to improve the radiation resistance of silicone rubber under the radiation of high energy radiation, so it is of great theoretical significance and practical value to improve the radiation resistance of silicone rubber. In this paper, Si O2- graphene oxide (G) is prepared from the methods of improving the radiation resistance of silicone rubber, "external protection" and "internal protection". O) / methyl vinyl silicone rubber (MVQ) and Si O2/ methyl vinyl phenyl silicone rubber (MVPQ). The compatibility of GO with the silicone rubber system and the irradiation effect of GO-Si O2/MVQ and the effect of phenyl on MVPQ radiation were studied. The compatibility of GO with the silicone rubber matrix and its dispersion in silicone rubber were investigated. The results showed that when GO was added. When the amount of 2 phr is 2, the synergistic effect of silicone rubber is the best. Compared with the silicone rubber with only Si O2, the tensile strength of 100% is increased by 37%, the tensile strength is increased by 17%, the elongation at break is increased by 8%. The initial modulus of the strain scanning is increased by the addition of GO, the Payne effect and the relaxation effect of the composite are all increased, and GO and Si O are reflected from another angle. 2.SEM, which has better physical reinforcing effect, shows that GO can be distributed more evenly in silicone rubber. In the third chapter, the radiation effect of GO-Si O2/MVQ is studied on the basis of the compatibility of GO and silicon rubber matrix. The tensile experiment shows that the mechanical properties of the silicone rubber after irradiation are significantly reduced after the addition of GO. After the radiation of 500K Gy, the tensile strength and elongation at break of MVQ with only Si O2 were 3.9Mpa and 96%, respectively, and the tensile strength and elongation at break were decreased by 30% and 77% respectively, and the tensile strength and breaking elongation of 2 GO added MVQ were 5.1Mpa and 142% respectively. The tensile strength and tensile strength of the 2 GO added Gy were respectively the tensile strength and the tensile strength of the 2 GO. The elongation at break decreased by 23% and 68%., respectively, indicating that GO can obviously improve the radiation resistance of silicone rubber, which is attributed to the quenching effect of GO on the free radicals produced by radiation, and its good gas barrier properties, which can reduce the effect of oxygen on radiation aging, so the.DMA test with good radiation protection shows that the radiant effect is very good. After illumination, the initial modulus of the strain scanning of the composites with different GO additions increased, indicating that the radiation induced cross-linking reaction was the smallest change of the energy storage modulus of the silicon rubber before and after the irradiation of the dominant.2 GO, indicating that the radiation was the least affected, and the best.TGA analysis of the radiation resistance showed that after irradiation, the thermal stability of GO-Si O2/MVQ was stable. The degradation of the molecular chain caused by radiation is caused by irradiation, which is caused by the degradation of the molecular chain of silicon rubber by irradiation. Among them, the decomposition temperature of the MVQ weight loss 5% without GO is the most. The effect of the introduction of benzene on the irradiation effect of MVQ is explored. The results show that the tensile strength and elongation at break of MVQ without two phenyl group are compared with the irradiation after radiation of 500K Gy. The reduction of the tensile strength and the elongation at break of the silicone rubber before and after irradiation was reduced by 30% and the content of 77%.10% two phenyl respectively, and the tensile strength and elongation at break decreased. The radiation resistance increased first and then decreased slightly as the content of benzene increased, which was attributed to the dispersive radiation energy absorbed by the large pi bond of the benzene ring. However, the content of benzene is too large, which hinders the vulcanization and weakens the chemical reinforcement. Dynamic mechanical testing and relaxation experiments show that the greater the content of the phenyl group, the more obvious the hindering effect on irradiation crosslinking.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ333.93

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