Lignin-polyurea/luffa seed oil microcapsules for anti-mold modification of bamboo

Bamboo has shown enormous potential across construction, furniture, and other fields as an efficient replacement for wood. However, during its application, bamboo is susceptible to microbial infection and mildew, resulting in damage to the internal structure that adversely affects its mechanical properties. In the present study, lignin-based polyurea resin/luffa seed oil (LSO) microcapsules (LSO@LPMC) were prepared by interfacial polymerization method. These microcapsules were then applied on bamboo for mold-prevention modification through vacuum impregnation and epoxy resin-microcapsule coating, which significantly improved the mold resistance of bamboo. Microcapsules could alleviate the excessive release of carbon and nitrogen sources within the LSO. The prepared LSO@LPMC exhibited a high encapsulation efficiency (90.76 %) and excellent sustained release performance. LSO benefited from active functional groups including aldehyde and carboxyl groups, thus the enzymes and proteins on the cell surface could be easily deactivated, ultimately leading to microbial lysis and death. The bamboo samples modified with microcapsule coating exhibited excellent antifungal activity and mechanical properties. The processing technology of these microcapsules provides a theoretical reference and practical foundation for the promotion and application of LSO in the field of anti-mold modification of bamboo.