Nano-TiO 2 particles were used as photo-catalysts and ferric stearate (FeSt 3 ) powders were used as the thermo-oxidant promoters for degradable low-density polyethylene films in order to increase the rate of abiotic degradation of waste PE in the natural environment. The TiO 2 –FeSt 3 –polyethylene (TFPE) composite film was synthesized through two stages: a melt-granulating process and a film-blowing process. The final TiO 2 and FeSt 3 in composite film were controlled at around 1 wt%. The film thickness was about 25 μm. The photo-degradation and thermo-degradation of the composite film were investigated by exposing to UV irradiation for 240 h and/or in an air oven maintained at 70 °C for 30 days. Their residues were assembled in a aquatic test systems, and the effective biodegradation was assessed by monitoring the amount of CO 2 developed over time according to the international standards ISO 14852 (1999). After 30 days of thermo-oxidative degradation, TFPE film containing both TiO 2 and FeSt 3 exhibited the strong characteristic absorptions of the carbonyl group (> C=O) and the amorphous region in ATR-FTIR spectroscopy. The loss rate for tensile strength and elongation at break of TFPE film reached 60% and 97.7%. After 240-h UV irradiation, the weight loss of TFPE film was 14%, and also, the absorption peaks appeared for carbonyl (> C=O) group and hydroxyl group in FTIR spectroscopy. The results showed that the addition of TiO 2 and FeSt 3 into the PE film could promote the photo-degradation and thermo-oxidative degradation of PE film. A lot of oxygenated groups were inserted into PE matrix during photo- or thermo-aging treatments, which was helpful for further biodegradation of films. Residues of TFPE films could be degraded completely by microorganism after incubation in aqueous medium.

中文翻译：

---

光催化剂和热氧化添加剂对聚乙烯的光降解和热降解性能

纳米TiO 2 颗粒用作光催化剂，硬脂酸铁（FeSt 3 ）粉末用作可降解低密度聚乙烯薄膜的热氧化促进剂，以提高废PE在自然环境中的非生物降解率. TiO 2 -FeSt 3 -聚乙烯（TFPE）复合薄膜通过两个阶段合成：熔体造粒过程和吹膜过程。复合膜中的最终TiO 2 和FeSt 3 控制在约1wt%。膜厚约为25μm。通过暴露于紫外线照射 240 小时和/或在保持在 70°C 的空气烘箱中保持 30 天来研究复合膜的光降解和热降解。它们的残留物被组装在一个水生测试系统中，根据国际标准 ISO 14852 (1999)，通过监测随时间推移产生的 CO 2 量来评估有效生物降解。经过 30 天的热氧化降解，包含 TiO 2 和 FeSt 3 的 TFPE 薄膜在 ATR-FTIR 光谱中表现出强烈的羰基 (> C=O) 和非晶区的特征吸收。TFPE薄膜的拉伸强度和断裂伸长率损失率分别达到60%和97.7%。UV照射240小时后，TFPE薄膜的重量损失为14％，并且在FTIR光谱中出现羰基（> C = O）和羟基的吸收峰。结果表明，在PE薄膜中加入TiO 2 和FeSt 3 可以促进PE薄膜的光降解和热氧化降解。在光老化或热老化处理过程中，大量含氧基团被插入到 PE 基质中，这有助于薄膜的进一步生物降解。在水性介质中孵育后，TFPE薄膜的残留物可以被微生物完全降解。