Effect Of Trichoderma Viride Infection On The Main Performance And Chemical Components Of Wheat Straw Board

Since its introduction,the wheat straw board has received extensive attention from scholars and consumers by virtue of its green environmental protection.At present,the production of wheat straw board has a relatively mature process.However,in actual use,the wheat straw board is found to be more susceptible to mold damage than wood and other wood-based panels.Therefore,it is necessary to study the effect of mold infestation on the performance of the straw board.In this dissertation,wheat straw board was used as test material,and Trichoderma viride was used as experimental bacteria.The density of the wheat straw board was studied by the use of profile densitometer,mechanical testing machine,contact angle meter and dynamic moisture analyzer.The effects of physical properties such as strength,surface contact angle and hygroscopicity were investigated.The effects of Trichoderma viride infection on the chemical composition of wheat straw were investigated by high pressure liquid chromatography and Fourier infrared spectrometer.The conclusions are as follows:(1)After inoculation with Trichoderma viride,mycelium will soon appear on the surface of the wheat straw sample.After 1 week,the side of the wheat straw sample will be completely covered by the mycelium;after 3 weeks,the wheat straw sample will be The surface has been completely covered with Trichoderma viride.After 12 weeks of continuous culture,there is only a small amount of hyphae on the surface of Pinus massoniana and poplar.Trichoderma viride can cause serious changes in the color of the surface and interior of the wheat straw board,affecting the appearance.(2)After 12 weeks of infection with Trichoderma viride,the mass loss rates of masson pine and poplar were 2.25% and 1.49%,respectively,while the mass loss rate of wheat straw board reached 10.51% in the 4th week after infestation.By the 12 th week,the mass loss rate was as high as 17.82%,indicating that the wheat straw board's resistance to Trichoderma viride was much lower than that of wood.Because of the increased surface density of the sanded wheat straw board,the resistance to Trichoderma viride in the early stage of infection was greater than that of the unsanded straw board,which gradually converged in the laterperiod.(3)The cross-sectional density of the wheat straw board is geometrically symmetrical along the centerline of the thickness.The density of the surface layer is higher,and the core density is slightly lower.The maximum density is about 1~2 mm from the surface of the board.The continuous infection of Trichoderma viride for 12 weeks reduced the average density of wheat straw by about 30%,the internal bond strength by about 80%,and the surface contact angle increased.(4)The sorption isotherm of wheat straw board is similar to that of wood,wooden material particle board,rice straw board and other fiber materials,showing an "S" curve and obvious hysteresis hysteresis.Trichoderma viride infection increased the equilibrium moisture content of wheat straw board,but hysteresis hysteresis weakened.GAB model can well match the equilibrium moisture content of wheat straw board under different relative humidity.(5)Trichoderma viride has certain degree of degradation of cellulose,hemicellulose,lignin and ethanol extracts in wheat straw.In the early stage of infection(the first 4 weeks),Trichoderma viride has a faster degradation rate of xylan,lignin and ethanol extracts,and a slower degradation rate of cellulose;after 4 weeks,the degradation rate of cellulose Obviously accelerated,the degradation rate of lignin slows down.After 12 weeks of degradation,19.56% cellulose,27.22% xylan,9.30% lignin,and 31.90% ethanol extracts were degraded in the straw.And Trichoderma viride differs in the degradation of the surface layer and the core layer of the wheat straw board.