【作者】 王莉；

【导师】 王菊琳；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2023， 硕士

【摘要】 石质文物具有重要的历史价值与艺术价值,但由于各种因素的影响石质文物保存状态不容乐观。有机材料因其高延展性、成膜性、疏水性、粘结性等成为目前使用最多的文物保护材料,然而高分子保护材料易老化,尤其是环境中的紫外光容易使其失效从而失去保护效果。本文检测了常用石质文物保护材料环氧树脂（E44）、丙烯酸树脂（B72）紫外光老化过程中的性能变化并通过红外光谱、X射线光电子能谱、动态热机械分析、核磁共振波谱、凝胶渗透色谱等手段探究其老化机理。老化过程中断链与交联反应同时存在,只是在不同时期占据主导地位的反应不同。E44中光化学反应活性位点为芳香醚键、异丙基中CH₃-C键及交联点处C-N键,反应过程中生成致色基团C=O。B72光化学反应的活性位点为叔丁自由基,反应中生成γ内酯与C=C使B72性能发生变化。为改善E44、B72耐紫外光性,采用水解缩合法合成低聚倍半硅氧烷（POSS化合物）,探究不同原料配比对合成的POSS化合物结构的影响,确定最佳合成条件,探究不同种类及含量POSS化合物对E44、B72耐紫外光性能的影响。实验发现OTES-POSS、KH550-POSS在添加量5%～8%时可明显提高E44、B72耐紫外光性能,减少光化学反应产物的生成。通过冻融实验、盐老化实验、酸老化实验探究了POSS化合物对E44、B72其它耐久性的影响,从而全面评价POSS化合物改性的效果。实验结果证明POSS化合物对提高E44、B72耐紫外光性能,保持或提高冻融老化、可溶盐老化、酸老化后E44、B72性能具有较大作用,这为文物保护高分子材料耐老化改性提供了选择与依据。更多还原

【Abstract】 Stone cultural relics have important historical value and artistic value,but the preservation state of stone cultural relics is not optimistic because of various factors.Organic materials have become the most used cultural relic protective materials due to their high ductility,film-forming property,hydrophobicity and cohesiveness.However,the polymer protective material is easy to age,especially the ultraviolet light in the environment is easy to make it fail and lose the protective effect.In this paper,the properties of commonly used stone heritage protection materials epoxy resin（E44）and acrylic resin（B72）during UV aging were tracked and the aging mechanism was explored by means of infrared spectroscopy,X-ray photoelectron spectroscopy,dynamic thermomechanical analysis,nuclear magnetic resonance spectroscopy,gel permeation chromatography,etc.It is found that the interrupt chain of aging process and crosslinking reaction exist at the same time,but the dominant reaction is different in different periods.The active sites of the photochemical reaction in E44 were aromatic ether bond,CH₃-C bond in isopropyl group and C-N bond at the crosslinking point,and the chromogenic group C=O was generated during the reaction process.The active site of the photochemical reaction of B72 was tert-butyl radical.lactone and C=C were generated in the reaction,which changed the properties of B72.In order to improve the UV resistance of E44 and B72,polyhedral oligomeric silsesquioxane（POSS compounds）were synthesized by hydrolysis shrinkage method.The effect of different ratio of raw materials on the structure of POSS compounds was studied and the optimum synthesis conditions were determined.The effects of different kinds and contents of POSS compounds on UV resistance of E44,B72 were explored.It was found that OTES-POSS and KH550-POSS can significantly improve the UV resistance of E44 and B72 and reduce the generation of photochemical reaction products when the dosage of 5%-8%.The effects of POSS compounds on other durability of E44 and B72 were explored through freeze-thaw experiments,salt aging experiments and acid aging experiments,so as to comprehensively evaluate the modification effect of POSS compounds.The experimental results show that POSS compounds play a significant role in improving the UV resistance of E44 and B72,maintaining or improving the properties of E44 and B72 after freezing and thawing aging,soluble salt aging and acid aging.It provides a basis for selection and modification of antiaging polymer materials for cultural relics protection.更多还原