人工老化对聚乙烯醇缩丁醛力学性能的影响

Effect of Artificial Aging on Mechanical Properties of Polyvinyl Butyral

聚乙烯醇缩丁醛树脂(PVB)以其独特的力学性能广泛应用于夹层玻璃.为了研究环境老化作用对夹层玻璃中PVB层拉伸力学性能的影响,本文针对太阳光照(紫外辐射)和环境温度两种老化因素,开展了夹层玻璃的人工加速老化试验,并通过准静态拉伸和分离式Hopkinson拉杆(SHTB)试验研究了夹层玻璃中PVB层在不同辐照强度和不同温度下老化后的拉伸力学性能.结果表明:PVB胶层的拉伸力学性能具有很强的应变率敏感性,准静态加载下表现为粘弹性特征,而动态加载下表现出更强的脆性特征;PVB的拉伸强度会随着紫外辐照强度的增加或辐照时长的增加而减弱;在80℃高温环境中,PVB的拉伸强度会随着老化时长的增加而减弱,而在40℃环境中,其拉伸性能不会发生改变;温度老化的作用强于光照,老化因素对力学性能的影响随应变率的增加而增加.红外光谱测试表明,PVB试样在分别经过光照老化和高温老化后,均有羟基老化产物形成,说明部分材料发生了分解,从而导致了其力学性能的下降.

Polyvinyl butyral resin(PVB)is widely used in laminated glass due to its unique mechanical properties.In order to study the influence of environmental aging on the tensile mechanical properties of laminated glass,the artificial accelerated aging test of laminated glass was carried out according to the two aging factors of solar light(UV irradition)and ambient temperature.The tensile mechanical properties of PVB layer in laminated glass after aging at different irradiation intensities and temperatures were studied by quasi-static tensile test and split Hopkinson tension bar(SHTB)test.The experimental results show that the tensile mechanical properties of PVB adhesive have strong strain rate sensitivity,and under quasi-static loading,it shows viscoelasticity,while under dynamic loading,it shows more brittle characteristics.The tensile strength of PVB decreases with the increase of UV irradiation intensity or irradiation time.The tensile strength of PVB will decrease with the increase of aging time at high temperature environment of 80℃,while at 40℃,the tensile properties will not change.The effect of temperature aging is stronger than that of light,and the influence of aging factors on mechanical properties increases with the increase of strain rate.Infrared spectroscopy test showed that hydroxyl aging products were formed in PVB samples after light aging and high temperature aging,indicating that some material was decomposed,resulting in the decrease of mechanical properties.