【作者】 李林洁；

【导师】 于运花；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 玻璃纤维增强乙烯基酯树脂(GF/VE)复合材料因其优良的力学和耐腐蚀性能,常作为化学容器等较高耐腐蚀性要求的壳体材料使用。但是在实际应用中由于各种复杂的环境因素(湿度、温度、化学介质等)的协同作用,复合材料的树脂基体、增强纤维和界面会受到不同程度的腐蚀,对复合材料的力学性能产生很大的影响,从而影响其使用寿命。因此,模拟GF/VE复合材料的实际使用环境研究其腐蚀行为,对选取性能优异的壳体材料及其使用寿命的预测具有非常重要的指导意义。本文选择两种玻璃纤维增强乙烯基酯树脂复合材料(GF/VEA和GF/VEB)及其树脂基体(VEA和VEB),对比研究其静态和动态力学性能及其在55℃、40wt%硫酸水溶液中的变化以及吸湿特性,并用SEM和FTIR分析其微观结构和组成变化,研究界面粘结对两种复合材料在硫酸介质中腐蚀行为的影响。进而选择界面粘结性能和耐蚀性能较好的GF/VEB复合材料,对其在去离子水和硫酸介质中的腐蚀行为进行比较,并采用材料强度预测模型对GF/VEB复合材料进行弯曲强度的寿命预测。静态和动态力学性能测试结果表明,复合材料GF/VEB较GF/VEA具有更好的界面粘结性能。通过对相同的浸泡时间内两种复合材料及其树脂浇注体在硫酸介质中的质量变化率比较和红外分析表明,VEA和VEB两种树脂在硫酸溶液中的耐蚀性能相似,从而GF/VEA和GF/VEB复合材料耐酸蚀性能的差异主要取决于界面粘结的不同。通过动态力学性能、剪切性能和弯曲性能的研究表明,纤维与树脂界面粘结情况越好,复合材料的性能保留率越高。从而复合材料GF/VEB的耐酸性能优于复合材料GF/VEA。因此,两者相比,复合材料GF/VEB更适合作为防腐容器壳体材料使用。通过对GF/VEB复合材料在去离子水和硫酸溶液中的腐蚀行为比较表明,在去离子水中,GF/VEB复合材料的腐蚀主要因吸湿塑化和轻微的界面脱粘导致弯曲强度轻微下降,而弯曲模量几乎不变；而在硫酸介质中,除了吸湿塑化还因树脂基体的水解脆化和玻璃纤维的裂纹化,导致更严重的界面脱粘破坏,从而弯曲强度和弯曲模量均有明显的降低。采用材料强度预测模型对GF/VEB复合材料进行弯曲强度预测,预测值与试验值拟合较好,并根据材料的弯曲强度对GF/VEB复合材in料的使用寿命进行预测,结果表明GF/VE复合材料在硫酸溶液中的使用寿命比其去离子水中的使用寿命短约16倍。更多还原

【Abstract】 Glass fiber reinforced vinylester composites (GF/VE) have been used as shell materials for chemical containers due to superior mechanical properties and good corrosion resistance. However, in practical applications, these composites may take degradation in mechanical properties owing to the corrosion of the matrix, glass fiber and interface of the composites by the synergy of complicated environmental factors (humidity, temperature, medium, et al), resulting in the deterioration in service performance and long-term durability. Therefore, it is necessary to study the corrosion behavior of the GF/VE composites by simulating actual service environment for the purpose to select suitable shell materials for chemical containers.In this study, the moisture absorption, static and dynamic mechanical properties of two kinds of glass fiber reinforced vinylester resin composites (GF/VEA and GF/VEB) and their resin casts (VEA and VEB) in 55℃,40wt% sulfuric acid solution were comparatively studied. The microstructure and componential change were also studied using SEM and FTIR analysis. The results show that the GF/VEB composite presents a better interfacial adhesion and thus shows higher corrosion resistance than the GF/VEB composite. So the GF/VEB composite is chosen as a more suitable shell material for anticorrosive containers, and has been taken further studies in this study.In order to further investigate the corrosion mechanisms of the GF/VEB composite in sulfuric acid solution, we further comparatively investigated the corrosion behavior of the GF/VEB composite and VEB casts in distilled water and sulfuric acid solution. The results show that the flexural strength of GF/VEB composite in distilled water decline slightly and the flexural modulus is almost unchanged due to the plasticization resulting from moisture absorption and the slight interfacial de-bonding. While in sulfuric acid solution, both the flexural strength and the modulus of the GF/VE composite decrease clearly because of the more severe damages on the interface adhesion, which result from the brittleness and cracking of matrix, the cracking and/or breakage of glass fibers as well as the plasticization of the matrix.The materials strength prediction model for polymer composite laminates was applied in this paper. The good consistency between the predicted and experimental values indicates that the model can be applied to predicate the residual strength and service lifetime of the GF/VE composite. The results show that the GF/VE composite in sulfuric acid solution presents almost 16 times shorter life time than in distilled water when the 50%of flexural strength retention is considered as the failure point.更多还原