硝基清漆的自动氧化及其光解作用的研究

AUTOXIDATION AND PHOTODEGRADATION OF NITROCELLULOSE LACQUERS

本文以硝基漆膜为研究对象,考察了其在大气中的自动氧化作用。探讨了作为木质器具中固有的金属离子(Fe^(+3)、Fe^(+2))、木质素、苯酚等成分对漆膜稳定性的影响。通过紫外光谱和傅立叶变换红外光谱分析,重新估价了紫外光对硝基漆膜的降解作用。

Nitrocellulose films were sensitive to oxygen and readily autoxidized in air to produce hydroperoxide impurity during storage. Autoxidation of nitrocellulose films led to gradual denitration and depolymerization. Ferric and Ferrous ions, phenol and lignin did not exert any advers effect on denitration of nitrocellulose films. However, with the exception of ferrous ions, the other additives did reduce molecular weight of nitrocellulose films, i.e. promoting the depolymerization of nitrocellulose films during autoxidation. Nitrocellulose films, with or without the presence of Fe^(+3), were susceptible to photodegradation. Denitration, depolymerization and crosslinking reaction took place during the process of photoirradiation. It was evident that oxygen was necessary to be an important element that was required for the crosslinking reaction, and crosslinking structure comprised oxygen and a nitrate group, which appeared to be degraded by prolonged UV irradiation and conduct to the significant degradation of crosslinked struct- ure and China scission. Analysis of FTIR spectra also revealed that the presence of carbonyl group on the irradiated nitrocellulose films,