Rojas-Trejo M F, Valadez-Gonzalez A, Veleva L, Benavides R, Rodriguez-Hernandez M T, Moreno-Chulim M V
Unidad de Materiales, Centro de Investigación Científica de Yucatán, Calle 43 No. 130 Col. Chuburná de Hidalgo, Merida 97205, Mexico.
Applied Physics Department, Center for Research and Advanced Studies (Cinvestav-Mérida), Merida 97310, Mexico.
Polymers (Basel). 2025 Jan 14;17(2):193. doi: 10.3390/polym17020193.
This research addresses the study of the combined effect of two abiotic treatments, a thermo-oxidative treatment followed by a photo-oxidative treatment with ultraviolet light, on the physicochemical properties of commercially available low-density polyethylene films with an oxo-degradant additive (OXOLDPE) and without (LDPE). The change in the oxidized film properties was characterized using FTIR, XRD, TGA, GPC, and SEM analytical techniques. The results indicated that the increment in carbonyl index (CI) and crystallinity percentage (X) was higher for those films that received the combined oxidative treatments compared with those that received only one of them, thermo- or photo-oxidative treatment. Moreover, the combined oxidative treatments produced more ester and carboxylic groups on the degradation products than the other single treatments. An analysis of variance (ANOVA) was carried out, and a synergistic effect was observed between the thermo- and photo-oxidative treatments for both ester and carboxylic degradation products. TGA results revealed that the loss of thermal stability in the films was more significant after their exposure to the combined thermo- and photo-oxidative treatments compared with those which received only one. The GPC results showed that the combined oxidative treatment is necessary to decrease the Mz and M average molecular weight of degraded films containing an oxo-degradant additive to the same extent as MW and Mn. The SEM surface appearance of the films changed more drastically after their exposure to the combined thermo- and photo-oxidative treatments, and they seemed to erode with the presence of inorganic fillers (CaCO). These results suggest that the combined oxidative treatments produced degradation products with lower molecular weight and greater content of ester and carboxylic groups that should enhance its environmental biodegradability.
本研究探讨了两种非生物处理（先进行热氧化处理，随后用紫外线进行光氧化处理）对含有氧化降解添加剂的市售低密度聚乙烯薄膜（OXOLDPE）和不含该添加剂的低密度聚乙烯薄膜（LDPE）物理化学性质的联合影响。使用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、热重分析（TGA）、凝胶渗透色谱（GPC）和扫描电子显微镜（SEM）分析技术对氧化薄膜性能的变化进行了表征。结果表明，与仅接受热氧化或光氧化单一处理的薄膜相比，接受联合氧化处理的薄膜的羰基指数（CI）和结晶度百分比（X）的增量更高。此外，联合氧化处理在降解产物上产生的酯基和羧基比其他单一处理更多。进行了方差分析（ANOVA），观察到热氧化和光氧化处理对酯类和羧基降解产物均有协同作用。TGA结果表明，与仅接受单一处理的薄膜相比，薄膜在接受热氧化和光氧化联合处理后热稳定性的损失更为显著。GPC结果表明，对于含有氧化降解添加剂的降解薄膜，要将Mz和M平均分子量降低到与MW和Mn相同的程度，联合氧化处理是必要的。薄膜在接受热氧化和光氧化联合处理后，其SEM表面外观变化更为剧烈，并且在存在无机填料（CaCO）的情况下似乎发生了侵蚀。这些结果表明，联合氧化处理产生了分子量较低、酯基和羧基含量较高的降解产物，这应该会增强其环境生物降解性。
