【作者】 胡艳巧；

【导师】 刘力；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 本论文的研究工作主要分为两部分：第一部分为稀土／聚甲基丙烯酸甲酯(PMMA)有机玻璃的制备及其结构与性能的研究；第二部分为采用溶胶-凝胶法制备防辐射无机玻璃及其结构与性能的研究。第一部分主要成果如下：(1)首次采用原位反应法制备防辐射稀土/PMMA有机玻璃。研究了稀土/PMMA有机玻璃的合成工艺,考查了不同反应温度、物料配比等反应条件对有机玻璃成型外观的影响。结果表明：采用先预聚合、后注模的本体聚合法制备稀土盐有机玻璃；预聚合温度为78-83℃；反应时间为20-60min；低温聚合5-7h；高温聚合lh,脱模即可得到透明的有机玻璃。(2)对稀土/PMMA有机玻璃进行了TEM、透光率、耐溶剂性、防辐射性能的测试。研究结果表明：稀土相在复合材料中分散均匀,粒径尺寸在40nm左右；当稀土盐含量低于20%时,稀土/PMMA玻璃的射线透光率均可达80%；稀土有机玻璃在丙酮溶剂中只发生溶胀,具有较好的耐溶剂性；在相同厚度的复合材料中,材料的屏蔽性能随着稀土含量的增加而增加。(3)对稀土盐玻璃和含铅玻璃在管电压40-88kev的防辐射性能进行比较,结果显示,Sm(MMA)3/PMMA有机玻璃满足透光率且当管电压处于100kVp时,稀土盐玻璃的铅当量(0.01025)高于含铅玻璃(0.00945),符合国家标准(0.01-0.04),说明在此能量范围内稀土盐玻璃可替代含铅玻璃满足防辐射要求。第二部分主要成果如下：(1)研究了防辐射凝胶玻璃制备过程中的各种因素(酸度、溶剂、用水量、温度等)对玻璃成型外观的影响,确定了凝胶玻璃的配方和工艺条件。结果表明,制备凝胶玻璃需满足以下条件：在H2O、TEOS、HNO3、Gd(NO3)3的混合液中,H2O/TEOS的摩尔比值为15-24；最佳PH值为3-4；最佳放置温度为30℃-50℃；陈化时间为30天以上。(2)对稀土盐凝胶玻璃进行了FT-IR、XRD和透光率测试。结果表明,凝胶玻璃中有Si和稀土Gd的存在,且当Gd(NO3)3含量低于5%时凝胶玻璃的透光率达70%以上。更多还原

【Abstract】 This thesis includes two parts:(1) Preparation and proerties of rare-earth/polymethyl methacrylate (PMMA) anti-radiation composites; (2) Anti-radiation inorganic composites prepared by sol-gel technology.The first part studied the preparation of anti-radiation PMMA and the relations between its structure and properties. The main results are as follows:(1) Anti-radiation rare-earth/PMMA was prepared by in-situ polymerization. The process included a first step preplolymerization and a second step bulk radical free polymerization in a mould. After polymerized MMA under 78-83℃for 20-60min first, put the prepolymerized agents into the mould for 5-7h next, and then polymerized it under higher temperature, transparent PMMA would be attained.(2)It is proved that the grain diameter of rare-earth in the composite is about 40 nm and the grain is well-distribute through TEM, transmittance, solvent resistance and Anti-radiation research of rare-earth/PMMA synthetic glass. The transmittance of these synthetic glass can all reach to 80% when the contents of rare-earth was below 20%; the solvent resistance is good because only swelling happened when put it into solvents; Shielding performance enhanced with increased the contents of rare-earth. (3) Comparing the shielding properties between lead free rare-earths glasses and lead glasses under tube voltage of 40-88kev energy shows that, ray transmittance could reach to 85% when the contents of Sm(MMA)3 below 11%; if the tube voltage is 100kVp, the lead equivalent of rare-earth can reach to 0.01025 which accord to national standard(0.01-0.04) while the number of lead glasses was 0.00945. All the results indicated lead glasses could be replaced by rare-earth glasses when the anti-radiation property was needed.In the second part, sol-gel method was applied to prepare anti-radiation gel glass. The main results are as follows:(1) the effects of acidity, solvent, water consumption, temperature on bulk glass properties were studied, formula and technological conditions were confirmed. The result shows that, the preparation of bulk glass should meet the following terms:molar ratio of H2O/TEOS is 15-24; the optimum PH is 3-4; the optimum temperature is 30℃-50℃; aging time is 30 days or longer. (2) The performance included FT-IR、XRD and transmittance of rare-earth gel glass proves the existence of silicon and gadolinium, and the transmittance is more than 70% when the contents of Gd(NO3)3 below 5%.更多还原