摘要
聚丙烯材料在服役过程中常因受到高温、辐射、臭氧、潮湿、化学介质以及机械应力等因素的影响而发生氧化和分子内部的交联反应,其结构或组分发生破坏,最终影响其使用价值。本文通过分析聚丙烯材料在综合应用场景中的自然老化过程及其对材料力学性能的影响,基于试验分析和理论模型对其老化过程中的力学性能进行预测。结果表明:聚丙烯材料自然老化过程中,1 a时,拉伸强度和断裂伸长率下降速度较快;在1~2 a时,拉伸强度和断裂伸长率基本保持不变;2 a后,其拉伸强度和断裂伸长率则进一步加速下降。自然老化时间对聚丙烯材料的缺口冲击强度的影响不明显,而无缺口冲击强度则在前1 a内下降较快,1 a后无缺口冲击强度趋于稳定。聚丙烯材料在户外暴露的时间越长,其光泽度越低,但前1.5 a内的光泽度变化较大,而后变化逐渐减缓。聚丙烯材料在户外暴露时间越长,其色差越明显,且随着时间的推移,色差变化有逐渐加速的趋势。GM(1,1)模型在聚丙烯材料自然老化失效过程中关于材料性能预测的平均误差约3%,最大误差不超过4%,该模型的预测结果较为可靠。
During the process of service,polypropylene material is often affected by high temperature,radiation,ozone,moisture,chemical media and mechanical stress,which may cause oxidation and cross-linking reaction within molecules,destroying its structure or components,and ultimately affecting its use value.In this paper,the natural aging process and its impact on the mechanical properties of polypropylene material in comprehensive a polypropylene lication scenarios was analyzed,and the mechanical properties during the aging process was predicted based on experimental analysis and theoretical models.The results show that during the natural aging process of polypropylene material,the decrease rate of tensile strength and elongation at break is relatively fast in the first year.During 1-2 years,the tensile strength and elongation at breakeven remain basically unchanged.After 2 years,the decrease of the tensile strength and elongation at break further accelerates.The effect of natural aging time on the notched impact strength of polypropylene material is not significant,while the unnotched impact strength decreases rapidly in the first year,and then stabilizes after one year.The longer polypropylene material is exposed outdoors,the lower the gloss of the material is.However,the gloss change of the material is significant in the first 1.5 years,and then gradually slows down.The longer polypropylene material is exposed outdoors,the more obvious the chromatic aberration of the material is,and with the time passing by,the chromatic aberration change of the material gradually accelerates.The average error of GM(1,1)model in predicting material properties during the natural aging failure process of polypropylene material is about 3%,and the maximum error will not exceed 4%.The prediction results of this model are relatively reliable.
作者
杜凯
贲强
王晓强
DU Kai;BEN Qiang;WANG Xiao-qiang(State-operated Machinery Factory of Wuhu,Structural Department,Anhui Wuhu 241007,China;Shenyang Aerospace University,School of Aeronautics and Astronautics,Shenyang 110136,China)
出处
《失效分析与预防》
2023年第6期387-393,共7页
Failure Analysis and Prevention
基金
辽宁省高等学校创新人才项目(LR2019052)
教育部春晖计划国际合作项目(HZKY20220428)。
关键词
自然老化失效
灰度模型
塑料包装
材料性能
natural aging failure
grayscale model
plastic packaging
material properties
