| The processing and utilization of bamboo products are seriously affected by the problems of easy mildew,decay and deformation of bamboo.High temperature heat treatment,as an environmentally friendly physical modification of bamboo,can effectively improve the performance of bamboo and improve the quality of bamboo products.In this experiment,5-year-old fresh moso bamboo is treated by high temperature oil heat treatment with methyl silicone oil.The changes of chemical composition,surface quality,physical and mechanical properties,anti-corrosion and anti mildew properties of bamboo under different oil heat treatment temperature(140℃,160℃,180℃,200℃)and different oil heat treatment time(2 h,4 h,6 h)are studied,and the correlation between all performances are analyzed.These conclusions provide theoretical reference for improving the efficient utilization of bamboo and the main conclusions are as follows:(1)During the high temperature oil heat treatment,the temperature has a significant effect on the chemical composition of bamboo,while the time has no significant effect.With the increase of temperature and time,the content of cellulose and hemicellulose decrease,and the content of lignin increase accordingly.The starch content of untreated bamboo is 3.16%.After oil heat treatment,the starch content of treated bamboo is less than that of untreated bamboo,and gradually decreases with the increase of oil heat treatment temperature and time,which shows that high temperature oil heat treatment can effectively reduce the starch content of bamboo.(2)The results show that with the increase of oil heat treatment temperature and time,the number of hydroxyl and carbonyl decrease and the crystallinity increase,but when the oil heat treatment temperature is higher than 180℃,the relative crystallinity of cellulose decrease.After heat treatment of high temperature oil at 200℃ for 6 h,it is found that the parenchyma cells of bamboo show significant distortion,delamination and rupture,starch particles in the cell cavity are significantly reduced,and there is oil medium attached to the bamboo pits and surface,blocking the water and the invasion channel of some mycorrhizal hyphae,which improved the anti mildew and anti-corrosion effect and dimensional stability of bamboo.(3)After high temperature oil heat treatment,the weight loss rate of bamboo increases with the increase of temperature,and the equilibrium moisture content,air drying and absolute dry shrinkage rate decrease with the increase of oil heat treatment temperature and time,which shows that high temperature oil heat treatment can effectively improve the dimensional stability of bamboo.After high temperature oil heat treatment,the compressive strength,MOR and MOE are increase first and then decrease with the increase of oil heat treatment temperature.When the oil heat treatment temperature is 160℃ and the time is 2 h,the compressive strength is the largest;when the oil heat treatment temperature is 180℃,the timeis 2h,the MOR and MOE of bamboo are the largest.(4)After high temperature oil heat treatment,the surface color of Bamboo gradually deepened from bright yellow to dark brown,with the increase of treatment temperature and time,the color of A L*,Aa*,Ab*decrease,and AE*increase,and the effect of oil heat treatment temperature is more significant,the changes of △ L*,△a*,△b*and AE*in yellow bamboo surface are greater than that in green bamboo surface.After oil heat treatment,the contact angle between the surface of bamboo and water is less than 90°,which has a certain wettability,and the wettability of bamboo yellow surface is better than that of bamboo green surface;when the oil heat treatment process is 200℃ and 6 h,the wettability of bamboo green and bamboo yellow surface is similar,and the contact angle is reduced to 84.94°and 85.00°.(5)The antifungal ability of the treated bamboo is improved compared with the untreated one.When the heat treatment temperature is higher than 160℃;the antifimgal effect is better with the increase of heat treatment time.When the oil heat treatment process is 200℃ and 6 h,there are only a few hyphae on the surface of bamboo,and the antifungal effect is the best The mass loss rate of bamboo after high temperature oil heat treatment and brown rot fungus corrosion for 45 days is 0%-20%,and the corrosion resistance grade is not lower than that of corrosion resistance Ⅱ.When the oil heat treatment temperature is higher than 160℃,the mass loss rate of bamboo is lower than 10%,reaching strong corrosion resistance grade Ⅰ,and the anticorrosion performance is improved significantly. |
