Effects of a layered double hydroxide (LDH) on the photostability of wood flour/polypropylene composites during UV weathering

Abstract

In this study, a kind of layered double hydroxide, MgAl–CO₃-LDH, was synthesised and its effects on the photostability of wood flour/polypropylene (WF/PP) composites during weathering were investigated. WF/PP composites with different LDH loading levels were prepared and tested in a QUV accelerated weathering tester for a total 960 h. The surface color, surface gloss, and flexural properties of the composites were tested, accompanied by characterizations using SEM, ATR-FTIR, and TG. The results indicated that (1) the flexural properties of the LDH-loaded composites were improved; (2) the composites containing LDH showed less discoloration, fewer surface cracks, and less loss of flexural strength and modulus than the control group; (3) LDH played a positive effect on alleviating the photo-oxidation process of WF/PP composites, confirming its UV-shielding effect; (4) LDH enhanced the thermal stability of the composites before and after weathering.