Bamboo modification with Glycidyl methacrylate (GMA) microemulsion through in-situ polymerization and cross-linking

Glycidyl methacrylate (GMA) has great potential in bamboo anti-mildew modification because it could polymerize in-situ to produce high-molecular polymer and its epoxy groups could react with hydroxyl groups of nutrients in bamboo which cannot any longer serve as a nutrient source for mold. In this study, transparent GMA microemulsion was prepared with citric acid (CA) and further used for bamboo modification through in-situ polymerization and cross-linking reactions. The results showed that when the concentration of GMA microemulsion reached 6 % or higher, anti-mildew efficiency was 100 % for the modified bamboo. SEM, Raman spectra and XPS results indicated poly(glycidyl methacrylate) (PGMA) was mainly distributed in the bamboo cell wall and a small portion covered the surface of the cell lumen and starch particles. Besides, chemical bonds were formed between the PGMA and the cell wall components/starch particles. Bamboo modification based on the physical coverage and chemical bonding of starch particles prevented mold from directly accessing the nutrients, leading to excellent anti-mildew property. The mechanical and thermal properties of the modified bamboo enhanced significantly due to the presence of PGMA in cell wall. The GMA microemulsion showed a great potential for bamboo modification application.