Preparation And Properties Of Abti-mold Coated Bamboo Packaging Materials

The development of the bamboo industry has been incorporated into the national strategic emerging industry system,but in the packaging industry,the proportion of bamboo used is much lower than that of plastic and wood.It provides a once-in-a-lifetime opportunity for the development of bamboo packaging.However,the problems of easy mold,easy cracking,easy aging,etc.exist in bamboo,which limit its popularization and application.In this study,bamboo glulam was used as the test material,and the test materials were impregnated with appropriate concentrations of boric acid/borax,IPBC,Na BF₄/DDAC,and tebuconazole antifungal agent.The water-based polyurethane coating（WPU）was modified by three kinds of ultraviolet absorbers,namely azoles（UV1130）,nano-Ti O₂ and nano-Si O₂,and the dipped test material was coated to prepare a mildew-proof coated bamboo packaging material.The physical and chemical properties,molecular structure changes and thermal stability of different modified coatings were studied.With the help of ANSYS finite element simulation analysis of the stress and strain of the painted bamboo tray,the ideal preparation process and performance of the anti-mildew painted bamboo packaging material were finally determined,in order to provide a technical basis for its industrial production.The specific research results are as follows:（1）The screening results of bamboo antifungal agents showed that the concentration ratios of four antifungal agents of boric acid/borax,IPBC,Na BF₄/DDAC and tebuconazole reached 3%,0.5%,1.5%,At 0.4%,its protection against three molds is close to 100%.（2）The modification results of mildew-proof waterborne polyurethane coatings show that,compared with unmodified WPU coatings,boric acid/borax/nano Ti O₂/WPU（C7）,boric acid/borax/nano Si O₂/WPU（C4）,boric acid/The three different modified coatings of borax/UV1130/WPU（C1）have stronger wear resistance,and all have good temperature resistance,but their surface water contact angles are reduced to varying degrees;the curing process of the modified coatings Among them,UV absorbers and antifungal agents will interact with the C-N,C-O and C=O bonds in the coating,thereby changing the molecular structure;different modification treatments can improve the thermal stability of the coating,among which the thermal stability The order of sex is:C4>C7>C1>C0.Different modified coatings have a certain degree of control effect on Aspergillus niger,but the effect is limited.（3）The outdoor weather resistance test of bamboo glulam shows that M1（boric acid/borax+boric acid/borax/UV1130/WPU）,M2（boric acid/borax+boric acid/borax）,compared with M0（non-impregnated antifungal agent+WPU）/Nano-Ti O₂/WPU),M4（IPBC+boric acid/borax/UV1130/WPU）,M8（Na BF₄/DDAC+boric acid/borax/nano-Ti O₂/WPU）modified coatings have no coating peeling,defects,adhesion Grade 1,the wear resistance of the coating meets the requirements of outdoor application standards,and can effectively improve the moisture resistance,water resistance and bending strength of the coating,and has excellent anti-mildew performance,and no obvious mildew is found on the surface of the coating;The ANSYS finite element simulation results show that when used outdoors,compared with the material and unmodified WPU-coated bamboo trays,the deformation of the painted bamboo trays with different modification treatments can be significantly reduce.Among them,M8 has the best performance in all aspects.