Performance elevation of bamboo flour/high-density polyethylene composites by pretreating bamboo flour with mussel adhesive proteins-inspired poly(catechol/amine)

To elevate performance of bamboo flour/high-density polyethylene (BF/HDPE) composites, poly(catechol/amine) (i.e., an adhesive material inspired by mussel adhesive proteins) treatment of BF was researched for the first time. Influence of monomer type was surveyed by applying three representative monomers, i.e., catechol/diethylenetriamine (catechol/DETA), catechol/triethylenetetramine (catechol/TETA), and catechol/tetraethylenepentamine (catechol/TEPA). All the monomers constructed poly(catechol/amine) coatings on BF. Among treated BF, poly(catechol/amine) uploading was 7.21–15.16%, which enlarged the average diameter of BF by 17.53–24.33%. After treatment, the potential of BF to interact with other substances was raised. When using different monomers, fractal dimension and specific area of BF surface were promoted by 3.58–4.31% and 14.08–16.81%, respectively; catechol/DETA and catechol/TEPA also reduced water-BF contact angle by 4.05–6.03°, and increased adhesion work by 8.50–12.69%. The treated BF showed a better interfacial bonding with HDPE, which was verified by physical–mechanical properties of composites. With the change of catechol/amine, composites made from treated BF exhibited a decrease in pore volume and 720 h water absorption by 6.71–15.49% and 42.57–46.54%, respectively, and an increase in flexural strength and distortion temperature by 13.13–23.14% and 3.60–7.30 °C, respectively. Overall, the optimal property enhancement for composites was observed in poly(catechol/TEPA) treatment.