摘要
本文选用Fe3 + 油酸的组合物为降解剂 ,研究它与淀粉、聚乙烯共混体系在模拟堆肥温度 (70℃ )下的热氧化降解行为 ,对其力学性能、分子量下降率及氢过氧化物浓度进行跟踪测试 ,并通过扫描电子显微镜(SEM )及X 射线衍射仪 (XRD)对试样的表面形态和结晶性能进行表征 .实验结果表明 :含有Fe3 +的有机化合物降解剂在实验条件下对试样有明显的促降解作用 ,并且高Fe3 +含量的降解剂催化PE基体降解活性的发挥受环境因素特别是氧气浓度高低的影响不敏锐 ,而低Fe3+含量的降解剂则与之相反 .在上述实验事实的基础上推导出该体系中聚乙烯热氧化降解的动力学方程式 .
The thermal\|oxidative degrading regulation of blends containing starch,polyethylene and additives which is made up of combination of Fe\+\{3+\}\|oleic acid at simulating composting temperature(70℃) was stdied.Sample films were made by conventional extrusion blowing.The additives and starch were introduced into the LDPE matrix in the form of masterbatchs in the amount of 10%( W/W ) and 60%( W/W ),respectively.Samples were put into two different degrading environments,a certain number of films were taken out after an interval of ten days for testing.The mechanical properties,viscosity\|average molecular weight and hydroperoxide concentration of the samples in the matrix were measured.Moreover,the superficial conformation and crystal capability of the aged samples were also characterized by SEM and XRD.It was showed that the adopted additives could catalyze the degradation of PE efficiently.Besides,it was found that though the concentration of O\-2 affected very much the degrading behavior of PE,the catalyzing efficiency of some additives,such as F5,with high content of Fe\+\{3+\} was almost unaffected under low O\-2 concentrations.So it was more suitable for initiating degradation of PE at real composting environment.The degrading mechanism of PE matrix was deduced according to the experimental results.The kinetics of hydroperoxide formation corresponded to an exponential law as claimed in the literature.The curve of hydroperoxide accumulation well conformed to a quadratic law in the early stage,when the progress deviated from the induction period,passed the maximum rate,and reached the limit concentration [POOH]\-∞ at deceleration.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2001年第1期99-104,共6页
Acta Polymerica Sinica
