无规共聚聚丙烯DSC原位加速老化研究

Study on Characteristics of Random Copolymer Polypropylene by DSC In-situ Accelerated Aging

对无规共聚聚丙烯(PPR)进行差示扫描量热(DSC)原位热氧加速老化特性研究,分析了老化温度对PPR熔点和热稳定性能的影响,通过傅里叶变换红外光谱法(FTIR)探究了老化温度与PPR分子结构变化之间的关系。结果表明,随着DSC热氧老化温度的上升,样品的老化作用逐渐加剧,对结晶结构的破坏程度增大。当热氧老化处理温度高于200℃时,样品的老化以氧化作用为主,且随热氧老化温度的升高,样品分子链的支化和断链程度加剧,同时伴随着交联现象,总体氧化稳定性变差。

The in-situ heat-oxidation accelerated aging characteristics of random copolymer polypropylene(PPR)were studied by differential scanning calorimetry(DSC).The effects of aging temperature on the melting point and thermal stability of PPR were analyzed.The relationship between aging temperature and PPR molecule structural changes were investigated by fourier transform infrared spectroscopy.The results show that with the increase of DSC thermal-oxidation aging temperature,the aging effect of the sample gradually increases,and the damage to the crystal structure is enhanced.When the temperature of the thermal-oxidation aging treatment is higher than 200 ℃,the aging of the sample is dominated by oxidation effect.As the thermal-oxidation aging temperature increases,the branching and chain scission of the sample molecular chain are intensified.Accompanying with cross-linking,the overall oxidation stability becomes worse.