Effect of poly(methylhydrogen)siloxane modification on adjusting mechanical properties of bamboo flour-reinforced HDPE composites

Poly(methylhydrogen)siloxane (PMHS) was applied for hydrophobic modification of bamboo flour (BF) at room temperature based on the dehydrogenation between hydroxyl groups of BF and -Si-H of PMHS, and the effect of PMHS modification on mechanical properties of BF/HDPE (high-density polyethylene) (BF/HDPE) composites was investigated. It was found that the hydrophobicity of BF were significantly improved by PMHS modification, and the mechanical properties of BF/HDPE composites could be adjusted effectively. PMHS with reactive hydrogen content of 1.5 % was the best candidate modifier for improving the strength of BF/HDPE, while PMHS with reactive hydrogen content of 0.2 % is more suitable to improve the toughness of BF/HDPE. More importantly, with optimal weight ratio of PMHS to BF, the strength and toughness of BF/HDPE could be improved simultaneously. After a systematic discussion on the results of FTIR, XPS, SEM and the chemical structure of PMHS, the relationship between microstructure and properties of BF/HDPE composites was built and then the mechanism for PMHS modification on BF/HDPE composites was proposed. [GRAPHICS] .

Automated summary

The hydrophobicity of bamboo flour was significantly improved by PMHS modification, and the mechanical properties of BF/HDPE composites could be adjusted effectively. PMHS with different reactive hydrogen content can enhance either the strength or toughness of BF/HDPE composites, and with the optimal weight ratio of PMHS to BF, both strength and toughness can be improved simultaneously.