Preparation And Performance Study Of Bamboo-wood Hybrid Scrimber

The physical and chemical properties of bamboo treated by carbonization and microwave was researched. Pretreated bamboo and wood bundle was selected to prepare bamboo-wood hybrid scrimber, the effect of pretreatment on physical and mechanical properties of bamboo-wood hybrid scrimber was researched. The effect of bamboo-wood hybrid ratio, solid content of adhesive and density of panel on physical and mechanical properties of bamboo-wood hybrid scrimber was researched by orthogonal test. The effect on physical and mechanical property, flame retardant, smoke suppression, thermal dynamic and pyrolysis property of bamboo-wood hybrid scrimber filled with Ca and Mg natural mineral powder was researched.1. The physical and chemical property of bamboo strip treated by carbonization and microwave was researched by the analysis methods of contact angle/interfacial tension meter, ESR, XRD and FT-IR. The physical and mechanical properties of bamboo-wood hybrid scrimber prepared by pretreated bamboo strips was researched. The research results showed that the contact angle of bamboo strip surface treated by carbonization is higher than that with no pretreatment, while the contact angle of bamboo strip surface treated by microwave is lower than that with no pretreatment. The free radicals concentration of bamboo strip treated by carbonization is decreased than that with no pretreatment, while the free radicals concentration of bamboo strip treated by microwave is increased. The relative crystallinity of cellulose in bamboo strip are both increased by carbonization and microwave pretreatment, the increasing extent of relative crystallinity treated by carbonization is larger than that treated by microwave. The number of hydroxyl in bamboo strip treated by carbonization is decreased, while the number of hydroxyl in bamboo strip treated by microwave is increased. The MOR of bamboo-wood hybrid crimber is decreased by the two pretreatment, the change of MOE is not obviously, the IB and TS of bamboo-wood hybrid crimber pretreated by carbonization is decreased, while the IB and TS of bamboo-wood hybrid crimber pretreated by microwave is increased. The mechanical strength and bonding strength of bamboo-wood hybrid scrimber pretreated by microwave are better than that pretreated by carbonization. The dimensional stability is worse than that pretreated by carbonization. The TS value of bamboo-wood hybrid scrimber pretreated by microwave is increased by13.4%than that of untreated one. Microwave is the best pretreatment.2. The effect on physical and mechanical properties of bamboo-wood hybrid scrimber made by bamboo-wood hybrid ratio, solid content of adhesive and density of panel was researched through method of range, variance and regression analysis. The results showed that density of panel has significant effect on MOR and MOE of bamboo-wood hybrid scrimber, bamboo-wood hybrid ratio had significant effect on TS of bamboo-wood hybrid scrimber, solid content of adhesive has significant effect on IB of bamboo-wood hybrid scrimber, The optimization of process is concluded, the density of panel is1.1, bamboo-wood hybrid ratio is60:40, solid content of adhesive is25%. The MOR of bamboo-wood hybrid scrimber prepared by optimal process is138.47MPa, the MOE is11563.52MPa, the IB is1.78MPa, the TS is2.68%.3. The thermal dynamic performance and pyrolysis kinetics of bamboo-wood composites filled with Ca and Mg natural mineral powder was researched by the analysis methods of TGA, PY-GC/MS, Li Chung-Hsiung and Malek. The research results showed that the temperature around bamboo-wood composites is reduced and the pyrolysis reaction of bamboo-wood composites is inhibited by free radicals inhibitor, CaO and MgO produced by pyrolysis. The content of CO,CO2and single benzodiazepines aromatic compounds from pyrolysis product of bamboo-wood composites filled with Ca and Mg natural mineral powder is decreased than that of untreated one, aliphatic compounds are increased than that of untreated one, speculated that the remove of oxygen containing functional groups are suppressed and carbonization reaction of lignin is catalyzed by Ca and Mg natural mineral powder. The pyrolysis model is builded, the pyrolysis model of bamboo-wood composites filled with Ca and Mg natural mineral powder is phase boundary reaction and spherical symmetry, while the pyrolysis model of untreated one is random nucleation, each particle has its own nuclear.4. The physical and mechanical properties of bamboo-wood hybrid scrimber filled with different dosage of natural mineral powder was researched. The effects of natural mineral powder on flame retardant and smoke suppression property of bamboo-wood hybrid scrimber were researched by the methods of TG, CONE, SEM and PY-GC/MS. The results showed that the physical and mechanical properties of bamboo-wood hybrid scrimber is improved by adding moderate dosage of natural mineral powder,the optimal dosage of natural mineral powder is10%. The heat transfer in bamboo-wood hybrid scrimber is prevented and the escaping channel of combustible gas is blocked by the uniformly filling effect of natural mineral powder. The gas concentration is diluted by the non-combustible gas produced by pyrolysis of natural mineral powder, the combustion chain reaction is suppressed by highly reactive free radicals produced by pyrolysis of natural mineral powder. The residual mass of bamboo-wood hybrid scrimber filled with natural mineral powder in TG curve at900s and burned by method of CONE at600s were increased than that of untreated one, which showed that natural mine powder has the effect of catalytic charing, because the remove of oxygen containing functional groups are suppressed and carbonization reaction of lignin is catalyzed by natural mineral powder.