摘要
聚甲基丙烯酸甲脂(PMMA)基于良好的综合性能得到广泛应用,但遇到极性溶剂时很容易发生溶胀,导致银纹的产生甚至出现开裂,严重降低了材料的服役寿命.本工作以某球形观察窗用有机玻璃为研究对象,深入探讨退火温度、退火时间、溶剂(乙醇)处理时间等因素对PMMA微观结构的影响,以及银纹产生与单轴拉伸、三点弯曲、压缩变形等力学性能的关系,研究发现在PMMA的玻璃化转变温度98 ℃附近进行退火容易出现肉眼可见的大尺度银纹.银纹对于力学强度的影响较小,但会降低材料的断裂应变.
Abstract
Polymethylmethacrylate(PMMA)had been widely used,due to its excellent comprehensive properties.However,it was prone to swelling when encountering polar solvents,leading to crazing or even cracking,which seriously reduced the service life of PMMA.This work focused on the study of a PMMA spherical observation window,and the effects of factors,such as,annealing temperature,annealing time,and solvent(ethanol)treatment time on the microstructure of PMMA was investigated,as well as the relationship among the formation of silver lines and uniaxial tensile,three-point bending,and compressive properties.It is found that annealing near 98 ℃,the glass transition temperature of PMMA is prone to inducing the visible large-scale craze.The influence of craze on the mechanical strength of materials is relatively small,but it could reduce the fracture strain significantly.
维普
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