191～#不饱和聚酯树脂西部曝晒和人工加速老化的研究

对191#不饱和聚酯树脂进行了自然曝晒老化、人工热氧加速老化及人工氙灯加速老化试验,并对老化前后试样的外观形貌、光泽度、黄色指数、拉伸强度和弯曲强度进行了研究。实验结果表明,随着加速老化的不断进行,试样表面会出现泛黄、失光率增大和裂纹等现象,强度呈先增后降的趋势,弯曲强度由20 MPa(未老化时)增至最大值40 MPa(热氧老化60 d或氙灯老化45 d),拉伸强度由113 MPa(未老化时)增至最大值125 MPa(氙灯老化30 d)和128 MPa(热氧老化60 d);老化方式不同,老化前后试样的性能变化也不相同,即失光率对热氧老化更敏感、强度对紫外光老化更敏感;西部曝晒180 d,不饱和聚酯树脂仍处于后固化阶段,但强度已开始下降,下降程度与曝晒地区有关,变化最明显的是新疆尉犁地区,弯曲强度由最大值40 MPa(自然曝晒120 d)降低至35 MPa(自然曝晒180 d)。

Study on 191# unsaturated polyester resin after western exposure and artificial aging

The aging behavior on 191# unsaturated polyester resin has been studied by natural exposure aging,thermo-oxidation(T-O) artificial aging-accelerated and xenon arc lamp(X-A) artificial aging-accelerated.The morphology,gloss,yellowness index(YI),tensile strength and bend strength of specimens before and after aging were investigated.The experiment results showed that the surface of specimens had increase phenomenon of yellow,loss of gloss and crack with aging time increase,the strength had trend from high to low,the bend strength was increased from 20 MPa(before aging) to max 40 MPa(after 60 d for T-O aging or after 45 d for X-A aging),the tensile strength was increased from 113 MPa(before aging) to max 125 MPa(after 30 d for X-A aging) and 128 MPa(after 60 d for T-O aging).If aging mode was different,the property changes before and after aging also were different,namely the loss of gloss was more sensitive to T-O aging,the strength was more sensitive to UV aging.After 180 d for western exposure aging,191# resin is just post cure,but its strength has been decreasing,different exposure area has different change,the most distinct is WEILI,XINJIANG area,the bend strength reduced from maximum value 40 MPa(after 120 d) to 35 MPa(after 180 d).