Effects of heat treatment temperatures on the photostability of Moso bamboo during accelerated UV weathering

Moso bamboo were heat-treated under saturated steam atmosphere at three different temperatures separately: 120°C (low temperature heat treatment, LH group), 160°C (medium temperature heat treatment, MH group), and 195°C (high temperature heat treatment, HH group). Then, the heat-treated bamboo slivers were placed in an accelerated UV weathering tester for a total of 960 h. The samples without any treatments (C group) were also prepared for comparison. After heat treatment, bamboo showed a darker surface color and increased lignin content, especially for those treated at higher temperatures. Compared to the C group, heat-treated samples exhibited less changes in surface color, gloss, morphology, and surface chemical groups after photodegradation, suggesting improved durability after heat treatment. Among them, the HH group exhibited the best photostability during the whole weathering process. The results revealed that higher lignin content and better surface hydrophobicity of heat-treated bamboo were the main reasons for their excellent photostability against weathering.