Synergistic modification of bamboo fibers by laccase-catechol/tetraethylenepentamine and preparation of poly(β-hydroxybutyrate) composites

This study explores a cost-effective and environmentally friendly surface modification of bamboo fibers to improve their interfacial compatibility with poly (β-hydroxybutyric acid). Laccase catalyzed the oxidation of bamboo fibers, increasing their active reaction sites and surface roughness so that the deposition of catechol and tetraethylenepentamine (TEPA) reactions on the bamboo fiber surface was promoted. The FTIR , XPS , and XRD results of bamboo fibers indicate that laccase can effectively oxidize lignin, generating oxygen radicals and promoting the reactive deposition of catechol and TEPA on the surface of the bamboo fibers, without destroying the structure of bamboo fibers. The TGA results of bamboo fibers indicate that when the concentrations of both catechol and TEPA are 15 mM, a laccase concentration of 150 U/L is more effective in enhancing the thermal stability of bamboo fibers. Furthermore, the mechanical properties of BFs/PHB composites showed that the addition of 200 U/L of laccase led to relatively good interfacial compatibility between bamboo fibers and PHB, tensile strength , flexural strength , flexural modulus and impact strength of the composite material respectively increased by 18.4%, 14.1%, 13.4% and 10.4%, while the tensile modulus decreased by 9.4%, compared to the composite material prepared with unmodified bamboo fibers.