陶瓷化硅橡胶复合材料的制备与性能研究

发布时间：2018-06-08 00:30

本文选题：陶瓷化反应 + 甲基乙烯基硅橡胶　；参考：《武汉理工大学》2015年硕士论文

【摘要】：为了降低日常生活中由于火灾而造成的人身以及财产危害,防火阻燃材料成为其中的关键问题。以前添加含卤阻燃剂,如十溴二苯醚,尽管阻燃效果优异,但是燃烧过程中释放了大量有毒有害的烟雾,被国内环保法禁用。目前主要采用无卤、低烟橡胶制品,例如硅橡胶乙丙橡胶、乙烯乙酸乙烯酯橡胶等,尽管有一定的帮助,但是长期使用时残余物没有足够的强度维持其结构的完整性,可能导致二次危害发生,限制了其更广泛的应用。可陶瓷化硅橡胶复合材料作为一种防火阻燃材料,在高温环境下已经取得了广泛的应用,有望在防火阻燃领域也有一定的使用价值。本论文以甲基乙烯基硅橡胶(VMQ)为基体,通过添加高岭土作为成瓷填料,制备了可以在高温环境下发生陶瓷化反应,生成具有自支撑结构的陶瓷体。本论文使用高岭土作为成瓷填料添加至硅橡胶基体中制备陶瓷化硅橡胶复合材料。TG-DSC测试显示,添加高岭土填料能够明显提高材料的热稳定性能,当高岭土的添加量为40wt%时,残留率为50.23%,而纯硅橡胶的残留率为37.33%。另外添加低熔点玻璃粉作为助溶剂,可以明显降低材料的T5以及Tmax,起始分解温度从417℃降至387℃,峰值分解温度也有50~70℃范围内的变化,最多时从512.4℃降至446.9℃。微观结构SEM结果显示,Kaolin/frits/VMQ大约从800℃左右发生有机-无机的陶瓷化转变,表面完整,没有明显裂纹或者空洞现象产生。扫面电镜分析在软化温度范围内,基体中会出现大量连续均匀的熔融状小球,EDS显示这些小球正是添加的玻璃粉助剂,它们此时可以很好的将基体与高岭土填料粘接起来。分析陶瓷化过程,发现CaO与基体的降解产物SiO2大约在600~800℃形成硅钙石wollastonite以及斜硅钙石larnite,其中在703℃时吸热转变为偏高岭土,随后再一次受热转变为莫来石,并且最后在12000C时出现了CaAl2O4的衍射峰。添加硼酸锌作为另一种助溶剂,制备陶瓷化硅橡胶复合材料。TG-DSC分析发现此时的残留率有较大变化,添加量为15wt%时,残留率为57.63%,高于Kaolin/frits/VMQ,而T5以及Tmax则略有降低,没有添加玻璃粉时明显。SEM扫描图像显示,大约从600℃开始,材料内部就会变致密均匀的网格状,温度越高,网格中空洞越小,在800℃时有十分明显的致密化变化,而当煅烧温度达到1000℃时,基体材料中会出现新的熔融液相,从EDS能谱分析发现此为“低共熔混合物”(eutectic mixture)能够将基体材料中的二氧化硅与高岭土成瓷填料很好的粘接起来,起到“桥连”的作用,于是可以在着火点以下发生固化,待冷却之后即可形成陶瓷结构,所以在此温度下煅烧获得的陶瓷体强度最高,结构最完整,表面裂纹也是最少的。添加高硅氧玻璃纤维作为增强材料可以有效改善陶瓷化硅橡胶的热力学性能。以玻璃粉为助溶剂时,残留率从54.00%提升至63.00%,另一组添加硼酸锌的硅橡胶复合材料也从57.63%提高到65.12%。同时两者的弯曲性能在600℃之后有明显的提高,在1000℃时达到最大值分别为1.89MPa,2.01MPa,较增强之前提高了1.19MPa和1.22MPa。
[Abstract]:In order to reduce the physical and property damage caused by fire in daily life, fire-retardant and fire-retardant materials have become the key problem. Halogen, low smoke rubber products, such as silicone rubber ethylene propylene rubber, vinyl acetate vinyl acetate rubber, etc., although some help, but in the long term use residue is not enough strength to maintain the integrity of its structure, may lead to two hazards and limited its wider application. Ceramic silicone composite material can be used as a fire protection. The flame retardant material has been widely used in the high temperature environment. It is expected to have a certain use value in the field of fire retardant and flame retardancy. In this paper, methyl vinyl silicone rubber (VMQ) was used as the matrix and kaolin was added as a porcelain filler. The ceramic reaction could be produced in high temperature environment, and the ceramic with self supporting structure was formed. The application of kaolin as a ceramic filler to the preparation of ceramic silicone rubber composite material in silicone rubber matrix.TG-DSC test shows that the addition of kaolin filler can obviously improve the thermal stability of the material. When the addition of kaolin is 40wt%, the residual rate is 50.23%, and the residual rate of pure silicone rubber is added to 37.33%.. The low melting point glass powder, as a cosolvent, can obviously reduce the T5 and Tmax of the material. The initial decomposition temperature is reduced from 417 to 387, and the peak decomposition temperature is also in the range of 50~70 C. At most, from 512.4 to 446.9 C, the microstructure SEM results show that the organic and inorganic ceramics turn around from about 800 degrees C. In the range of softening temperature, there will be a large number of continuous and uniform melting balls in the matrix, and EDS shows that these balls are the addition of glass powder additives. At this point, they can well bond the base with the kaolin filler. It was found that the degradation product SiO2 of CaO and the matrix formed about wollastonite of silicolite and larnite of the diagonal calcite at 600~800 C, in which the endothermic change into the metakaolin at 703 C, then the heat converted to mullite again, and the diffraction peak of CaAl2O4 at the end of 12000C, and the addition of zinc borate as a solvent to prepare pottery. The.TG-DSC analysis of ceramic silicone composites found that the residual rate was greatly changed at this time. When the addition amount was 15wt%, the residual rate was 57.63%, higher than that of Kaolin/frits/VMQ, while T5 and Tmax decreased slightly. When the glass powder was not added, the.SEM scanning image showed that the material would become dense and uniform in the meshes from about 600 degrees C. The higher the degree, the smaller the hole in the mesh, the more obvious densification at 800 C, and when the calcining temperature reaches 1000, the new molten liquid will appear in the matrix material. From the EDS spectrum analysis, it is found that the "low eutectic mixture" (eutectic mixture) can make the silica and kaolin in the base material good. It plays the role of "bridge connection", so it can be cured under the ignition point, and the ceramic structure can be formed after cooling, so the ceramic body obtained by calcining at this temperature is the highest, the structure is the most complete, and the surface crack is the least. Adding high silicon oxygen glass fiber as the reinforcing material can effectively improve the ceramics. When glass powder is used as a cosolvent, the residual rate is increased from 54% to 63%, and the other group of silicon rubber compound with zinc borate is increased from 57.63% to 65.12%., and the flexural properties of the two are obviously improved at 600 degrees C, and the maximum value is 1.89MPa, 2.01MPa at 1000 degrees centigrade, before the enhancement. Improved 1.19MPa and 1.22MPa.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

【参考文献】