聚α烯烃光催化降解的机理研究

Study on the Mechanism of Photocatalytic Degradation of Poly( α-olefin)

采用光催化微反应器对铜箔表面附着的聚α烯烃进行了光催化降解处理,利用X射线光电子能谱(XPS)、电子自旋共振谱(ESR)和傅里叶变换红外光谱(FTIR)等对光催化降解前后聚α烯烃的元素化学状态、自由基和官能团进行了检测,并探讨了光催化降解机理.结果表明,聚α烯烃光催化降解过程中发生了含氧基团的引入和CO_2脱附;参加降解反应的自由基主要为羟基自由基·OH,降解过程中—OH逐渐增多、C—H键逐渐减少;聚α烯烃光催化降解过程中,·OH进攻聚α烯烃是从取代反应开始的,首先取代的是末端的氢原子,然后是末端羟基向醛基和羧基的转变,最后是碳链断裂形成小分子有机物,这一过程持续进行,最终生成CO_2和H_2O等无机物.

Poly （α-olefin） （PAO, commonly used rolling base oil） attached to the surface of copper foil was degradated using photocatalytic microreactor. The chemical state, free radical and functional groups during the degradation process were detected by X-ray photoelectron spectroscopy （XPS）, electron spin resonance spectroscopy（ESR） and Fourier transform infrared spectroscopy（FTIR）. At last, the photoeatalytic degradation mechanism was discussed. The results show that the introduction of oxygen groups and the CO2 desorption exist in the degradation process and the main free radical is hydroxyl radical（ · OH）. The degradation process is accompanied the increase of -OH and the decrease of C-H bond. In the process of degradation of PAO, ·OH attacking polymer is from the beginning of substitution reaction, substituted the hydrogen atom of methyl group, then the formed -OH changes to carboxyl and then small organic molecules are formed. This process continues and the polymer molecular shorter and shorter and produce only CO2, H2O and other inorganic substances at last. photocatalytic firstly, · OH aldehyde, and chain become