Enhanced the weatherability of bamboo fiber-based outdoor building decoration materials by rutile nano-TiO2

• The photostability and thermal stability of bamboo fiber/HDPE composites were definitely enhanced by rutile TiO2.
• Both the positive and negative effects of nano-TiO2 on the weatherability of the composites were analyzed.
• Nano-TiO2 showed clearly impacts on the properties and structures of the composites.

This paper analyzes the impact of rutile nano-titanium dioxide (nano-TiO2) on the weatherability of bamboo fiber/high-density polyethylene (HDPE) composites using xenon-arc weathering accelerated tests. The results showed that a series of performance reduction containing color fading, surface cracking, structural transformations and loss of mechanical properties appeared on the composites during the accelerated weathering process. These attributes could be minimized to a greater extent using rutile nano-TiO2. The analysis revealed that, although free-radicals created by nano-TiO2 after absorbed UV light may resulted in the oxidization of bamboo fiber and HDPE, rutile nano-TiO2 mainly acted as light screening agent and ultraviolet absorbent, which retarded the photo-oxidative of the composites. Moreover, rutile nano-TiO2 enhanced the thermal stability by interacting with the molecular chain of bamboo fiber and HDPE which resulted into reduced thermo-oxidative aging of composites.