摘要
采用动态流变学方法研究了4种高密度聚乙烯(HDPE)的热氧老化与动态黏弹响应之间的关系。结果表明:当相对分子质量及支化度相近时,HDPE的抗热氧老化能力与其相对分子质量分布密切相关,相对分子质量分布越宽,在高温下越容易发生热氧老化;动态频率扫描时,随着热氧老化时间的延长,HDPE的储能模量明显增加,储能模量随角频率的变化曲线在低频区出现平台特征,且内耗(tgδ)随角频率的变化曲线在特定角频率下会出现峰值;动态时间扫描时,相对黏度随时间增加而增大;温度越高,热氧老化现象越明显;复合抗氧剂的加入能有效抑制HDPE热氧交联反应的发生。
The relationship between the thermo-oxidative aging behavior and dynamic viscoelastic response of four kinds of high density polyethylenes （HDPE） was studied by dynamic theological method. The results show that the anti-thermo-oxidative aging ability of HDPE depends on relative molecular mass distribution when they own similar relative molecular mass and degree of branching. The wider the relative molecular mass distribu- tion is, the more likely to happen thermo-oxidative aging phenomena is. During the dy- tlaml.c frequency scan, with the extension of thermo-oxidative aging time, the storage modulus of HDPE increases significantly, which is corresponding to the characteristic plat- eau at low frequency region of the curves of storage modulus with angular frequency,and the peak of the curves of mechanical loss （tgc？） wifh angular frequency appears at certain angular frequency. During the dynamic time scan, the relative viscosity increases with the extension of time. The higher the temperature is, the more obvious the thermo-oxidative aging phenomena is. The addition of composite antioxidants can effectively restrain the thermo-oxidative crosslinking reaction of HDPE.
作者
刘晶如
沈鹏
俞强
Liu Jingru Shen Peng Yu Qiang(School of Materials Science and Engineering, Changzhou University, Changzhou,Jiangsu, 213164)
出处
《现代塑料加工应用》
北大核心
2017年第5期1-5,共5页
Modern Plastics Processing and Applications
基金
江苏高校优势学科建设工程资助
关键词
高密度聚乙烯
热氧老化
动态流变行为
high density polyethylene
thermo-oxidative aging~ dynamic rheological behavior
