基于红外光谱法的PE-HD光氧老化行为及氧化物生成规律

采用衰减全反射傅里叶红外光谱技术分析了滚塑包装箱专用高密度聚乙烯（PE-HD）材料老化过程中羰基指数、羟基指数、支化程度、断链程度、不饱和度所对应特征谱带吸光度的变化趋势，进一步确定其老化行为，并通过对氧化产物特征谱带洛伦兹分峰，探究了不同类型氧化产物的生成规律。结果表明，整个老化周期内，材料不饱和双键吸光度呈现上升趋势，支化和断链程度呈现较大幅度的增长，且老化初期断链占主导地位，老化后期支化作用更显著；氧化产物生成规律表现出氧化产物以酮羰基为主，且羧酸羰基、酯羰基和醛羰基、γ内酯羰基在前期增长较快，后期增速放缓达到一个稳定值。

Degradation Behavior and Oxidation Products Analysis for High Density Polyethylene by Photo-oxidation Aging Based on Infrared Spectra Analysis

This article studied the xenon aging characteristics of high density polyethylene(PE-HD) used as rotational-forming packaging cases by attenuated total reflection infrared spectroscopy(ATR-FTIR). The changes in carbonyl groups, hydroxyl groups, branching degree, chain scission degree, and unsaturation degree were monitored to determine the degradation behavior. The spectra were analyzed by using Lorentz method, and the mechanism of the forming of various oxides was explored. The absorbance of unsaturation degree showed a trend of increase, while the branching degree and chain scission degree increased rapidly during the whole aging time. In early aging, the chain scission was predominant, but branching was more noticeble during later aging. The ketone was the primary oxidation product and the carboxylic acid, aldehyde, ester, and lactone products increased rapidly in the early aging progress, then slowly to a stable value.