Preparation and flame-retardant properties of CaCO3-mineralized decorative veneers
The flammability of decorative veneer restricts its application in furniture,interior decoration,and other fields.To enhance the flame retardancy of decorative veneer,this study implemented a biomimetic mineralization ap-proach by sequentially impregnating veneer with calcium chloride(CaCl2)and sodium bicarbonate(NaHCO3)solu-tions to in situ generate calcium carbonate(CaCO3).The flame retardancy of the modified veneer was characterized by the macro combustion testing,thermogravimetric analysis(TG)coupled with cone calorimetry(CONE),with the mineralization products analyzed via the Fourier transform infrared spectroscopy(FT-IR)and environmental scanning electron microscopy(ESEM).The results revealed that CaCl2 and NaHCO3 solutions produced calcite CaCO3 on the surface and interior of veneer,and the amount of CaCO3 produced increased with the increase of impregnation solution concentrations.The surface CaCO3 layer acted as a physical barrier against fire.As the concentration increased from 0.2 mol/L to 1.0 mol/L and above,the combustion time of the mineralized veneer was markedly prolonged.The Ca-CO3 also catalyzed pyrolysis of cellulose to favor char formation.TG results indicated that,at 1.8 mol/L concentra-tion,the residual char of mineralized veneer reached 28.05%,counting an 81.55%improvement compared to the un-treated veneer.This optimal concentration achieved the greatest flame retardancy,demonstrating the efficacy of biomi-metic mineralization for enhancing veneer fire safety.However,the transverse tensile strength of the mineralized ve-neer declined with the increase in impregnation solution concentration,which could compromise subsequent utility.An optimal concentration of 1.0 mol/L was determined to impart adequate flame retardance whilst preserving reasonable transverse tensile performance of the mineralized veneer.The CONE test results demonstrated that the mineralized ve-neer exhibited remarkably decreased heat release rate and effective heat of combustion compared to untreated veneer,indicating significantly enhanced flame retardancy.However,the transverse tensile strength of mineralized veneer was adversely affected,as evidenced by its gradual decline with increasing concentration of the impregnation solution,which could compromise subsequent serviceability.This study thereby recommends mineralizing veneer using an opti-mal concentration of 1.0 mol/L for the impregnation solution to attain adequate flame retardance whilst preserving transverse tensile performance to a certain extent.
万方数据
维普
