Polycarbonate (PC) is a good material for covering and protecting cultural heritage sites because of its durability, mechanical properties, and transparency. When bisphenol A polycarbonate is subjected to weathering conditions this polymer shows several degradation processes depending on the irradiation wavelength, humidity and temperature. In particular, the combined effects of humidity and UV irradiation speed up the PC molecular weight reduction. In this work, the decomposition mechanisms associated to the hydrolysis process are scrutinized and the effects of UV irradiation on the hydrolysis process are evaluated throughout the Density Functional Theory (DFT) approach. It was found that under UV irradiation the hydrolysis process is speeded up because of the geometrical rearrangement due to the photo-Fries process induced by the UV light.

聚碳酸酯（PC）的耐用性，机械性能和透明性是用于覆盖和保护文化遗产的好材料。当双酚A聚碳酸酯经受风化条件时，根据辐照波长，湿度和温度，该聚合物会显示出几种降解过程。特别是，湿度和紫外线辐射的共同作用加快了PC分子量的降低。在这项工作中，仔细研究了与水解过程相关的分解机理，并在整个密度泛函理论（DFT）方法中评估了紫外线辐射对水解过程的影响。已经发现，在紫外线辐射下，由于由紫外线引起的光-油炸过程引起的几何重排而加速了水解过程。