Study On The Anti-mildew And Anti-photodegradation Of Nano-SiO₂-IPBC Microcapsule Anti-mould Agent On Hevea Brasiliensis

With the implementation of the natural forest protection project,commercial logging of natural forests has been completely stopped,leading to serious scarcity of solid wood furniture products.Hevea brasiliensis is a wood that is harvested when rubber trees no longer produce latex,which shows enormous cost performance.Planting rubber trees on a large scale in China has stabilized the supply of rubber wood and gradually become one of the important production materials in the field of furniture decoration.However,its interior is rich in starch and sugars required for the growth of mold and,making it more susceptible to erosion by mold than other wood.In addition,wood is vulnerable to non-biological factors due to its own properties,resulting in light aging and discoloration.Therefore,it is of great significance to carry out anti mildew and anti-photodegradation treatment of rubber wood.Traditional anti-mould agent have disadvantages in the use process,such as environmental pollution,short durability,and easy to discolor treated wood.Therefore,developing a green anti-mould agent that maintains the primary color of wood and has long-term mildew prevention efficacy has become a topic worthy of research.In addition,secondary treatment is often required to achieve the goal of aging and discoloration of rubber wood due to long-term ultraviolet radiation.There is great potential to develop an anti-mould agent that has both anti mold and anti-photodegradation properties.In this paper,a nano SiO₂-IPBC microcapsule green anti-mould agent was prepared by vacuum blending method,using nano SiO₂ as the wall material and IPBC as the core material.The physical properties and leaching resistance of the anti-mould agent were studied,and the mildew resistance and photodegradation resistance of the anti-mould agent and the impregnated material were studied,providing a technical reference for"one dose multiple effect"anti-mould agent.（1）Aiming at the problems of short persistence and poor slow-release performance of IPBC anti-mould agent,the nano SiO₂-IPBC microcapsule anti-mould agent prepared by vacuum blending for three times has a uniform shape,high dispersion,a diameter distribution between 20 and 100 nm,and a loading rate of 46.33%,which has a good anti-mildew effect on mold and blue stain;Nano SiO₂ has a certain degree of thermal barrier protection for IPBC,delaying the pyrolysis time of IPBC;The coating form of nano SiO₂ plays a slow release role,effectively reducing the release rate of IPBC in ethanol aqueous solution.（2）Aiming at the problems of the fixation and mildew resistance of the anti-mould agent in wood,nano SiO₂-IPBC microcapsule anti-mould agent impregnated wood was characterized,indicating that it has good solidification performance,good mildew resistance,and high control effectiveness in wood.With the increase of the mass fraction of nano SiO₂-IPBC microcapsule anti-mould agent,the thickness of the solidified layer of the microcapsule on the rubber wood cell wall increases.The anti-mould agent with a mass fraction of 1.00%adhered uniformly to the cell walls and pits of the rubber wood impregnated material,and no significant loss occurred after one month of mildew prevention.Nanometer SiO₂-IPBC microcapsule anti-mould agent form a new chemical bond by combining with-OH inside the wood.Some microcapsules do not combine with-OH inside the wood,but are stabilized inside the wood through van der Waals force.（3）Aiming at the problem of light aging resistance of mold inhibitors,nano SiO₂-IPBC microcapsule anti-mould agent were subjected to light aging treatment,and it was found that they had good light stability.UV aging for 60 min only produced slight yellowing,and compared with IPBC,the light aging resistance was significantly improved.Light aging leads to degradation of lignin in the impregnated material,yellowing of IPBC impregnated material,and graying of nano-SiO₂-IPBC microcapsule anti-mould agent impregnated wood samples.Total color difference of nano SiO₂-IPBC microcapsule anti-mould agent impregnated wood samples with a mass fraction of 1.25%（ΔE）It is significantly smaller than IPBC impregnated wood samples and the control group,and the light aging resistance of nano SiO₂-IPBC microcapsule anti-mould agent impregnated wood samples is significantly improved.In conclusion,the prepared nano SiO₂-IPBC microcapsule anti-mould agent can effectively prevent the mildew and light aging yellowing of rubber wood.Nano SiO₂-IPBC anti-mould agent in this study can provide theoretical basis for production practice.