微波辐照对PET/PEN共混物非等温热降解行为的影响  

Effect of Microwave Irradiation on Non-isothermal Thermal Degradation Behavior of PET/PEN Blends

作　　者：石玉元[1] 李桂娟[1] 于祥[1] 孙中心[1] 王坤燕[1] 

机构地区：[1]长春工业大学化学工程学院,长春130012

出　　处：《中国塑料》2007年第7期39-43,共5页China Plastics

摘　　要：用热失重分析法(TGA)对微波辐照不同时间的 PET/PEN 共混体系的热降解行为进行了比较分析,用图解微分法和差减微分法计算了降解反应表观活化能(E),频率因子(InA)和反应级数(n)等降解反应动力学参数,并讨论了微波辐照对 PET/PEN 共混物热降解行为的影响及其机理。结果表明:微波辐照使 PET/PEN 共混物的降解反应活化能降低了约23～74 kJ/mol,起始降解温度降低了4.16～13.08℃,失重速率加快了0.06～0.27%/℃,从而促进 PET/PEN 共混物的降解,降解动力学参数(n)的值从0.83增大到了1.86,降解反应的机理由分解控制转为扩散控制。The non-isothermal thermal degradation behavior of the poly（ethylene terephthalate） （PET）/ poly （ethylene-2,6-naphthalate） （PEN） blends before and after microwave irradiation for different time intervals was investigated by means of thermogravimetric analysis （TGA） in nitrogen. The degradation kinetic parameters of the degradation for PET/PEN blends, incluing the apparent activation energy （E）, the reaction order （ n ）, and the frequency factor （lnA）, were analyzed by differential subtract differential and graphical differential analytical methods, the effect of microwave irradiation on thermal degradation behavior of PET/PEN blends and its mechanism were discussed. The microwave irradiation decreased the activation energy by 23 - 74 kJ/mol, the onset temperature of degradation reaction by 4.16 - 13.08 ℃, but increased the weight loss rate by 0.06 -0.27 % /℃, indicating an acceleration of the thermal degradation of PET/PEN blends. Furthermore, microwave irradiation increased the value of the degradation reaction order （ n ） from 0.83 to 1.86, which demonstrated the shift of the degradation mechanism from the decomposition control to diffusion control.

关 键 词：聚对苯二甲酸乙二醇酯/聚2 6-萘二甲酸乙二醇酯共混物 热降解行为 微波辐照 

分 类 号：TQ320.1[化学工程—合成树脂塑料工业]