Poly(butylene adipate-co-terephthalate) (PBAT) is considered as the most promising polymers for preparing biodegradable mulching films. However, PBAT films are suffered to severe weathering in use. This study aims to look into the effects of high amounts of micro-sized calcium carbonate and silane coated calcium carbonate on the weathering of PBAT films, as well as the effects of photooxidative degradation and hydrolysis on the weathering performance of neat PBAT and composite films. The effects of two different artificial weathering processes, namely only UV irradiation (dry condition) and UV irradiation + water spray condition, on the degradation rate of neat PBAT and its composite films were evaluated to distinguish the influences of photooxidative degradation and hydrolysis on the weathering of PBAT films. The results indicated that neat PBAT film had the fastest degradation rate under two different weathering conditions. After adding calcium carbonate, the degradation rate was delayed due to the shading effect of calcium carbonate. Comparing two different weathering conditions, it was found that degradation rates of PBAT in water spray conditions were higher than in dry conditions due to accelerated degradation rate via hydrolysis. However, in the water spray condition, the mechanical characteristics of the films containing silane-coated calcium carbonate degraded more slowly than in the dry condition. Although hydrolysis reaction accelerates the molecular weight reduction rate of PBAT, at the same time, silane molecules self-crosslink to form a three-dimensional network in the presence of water, thus compensating for the loss of mechanical properties of PBAT matrix caused by the decrease of molecular weight.

聚（己二酸丁二醇酯-共对苯二甲酸酯）（PBAT）被认为是制备可生物降解地膜的最有前途的聚合物。然而，PBAT 薄膜在使用中会遭受严重的风化。本研究旨在研究大量微尺寸碳酸钙和硅烷包覆碳酸钙对 PBAT 薄膜耐候性的影响，以及光氧化降解和水解对纯 PBAT 和复合薄膜耐候性能的影响。评估了两种不同的人工老化过程，即仅紫外线照射（干燥条件）和紫外线照射+喷水条件对纯 PBAT 及其复合膜降解率的影响，以区分光氧化降解和水解对老化的影响PBAT 薄膜。结果表明，在两种不同的气候条件下，纯 PBAT 薄膜的降解速度最快。添加碳酸钙后，由于碳酸钙的遮光作用，降解速度有所延迟。比较两种不同的风化条件，发现 PBAT 在喷水条件下的降解率高于干燥条件下，因为水解加速了降解率。然而，在喷水条件下，含有硅烷包覆碳酸钙的薄膜的机械特性比在干燥条件下退化得更慢。虽然水解反应加快了PBAT的分子量降低速度，但同时硅烷分子在水存在下自交联形成三维网络，