LPF胶黏剂制备及其在竹木复合集装箱底板的应用

Preparation of LPF Adhesive and Its Application in Bamboo-Wood Composite Container Bottom Plate

针对竹木复合集装箱底板弹性模量较低,酚醛树脂(phenol formaldehyde,PF)对环境危害大、脆性大以及木质素酚醛树脂(lignin-based phenol formaldehyde,LPF)合成反应进程中黏度控制难的问题,探究木质素酚醛树脂的制备条件,评价其替代传统酚醛树脂在竹木复合集装箱底板的应用效果。重点考察甲醛投加比、加水量、木质素替代率对胶黏剂黏度、胶合强度、固含量、游离甲醛含量的影响,以最优条件下制备的木质素酚醛树脂应用于竹木复合集装箱底板,以期提升其弹性模量、静曲强度等性能,并对木质素酚醛树脂进行FT-IR、DSC和SEM表征。研究结果表明:木质素添加量为苯酚质量分数的30%,第二次加水量为30 g,甲醛投加比为3∶7为最优条件,此条件下制备的LPF树脂胶合强度达到10.14 MPa,黏度为205.5 mPa·s(≤300 mPa·s),游离甲醛含量为0.29%(≤0.3%),耐水性良好。集装箱底板的弹性模量达到10245 MPa,较传统PF树脂制备的集装箱底板弹性模量提高18.37%。木质素的添加有利于改善胶黏剂的韧性以及集装箱底板的弹性模量。

Because of the low elastic modulus of bamboo-wood composite container floors,phenolic formaldehyde(PF)is hazardous to the environment,brittle and difficult viscosity control in the process of lignin-based phenol formaldehyde(LPF).This paper foucuses on the preparation conditions of lignin-based phenolic resin(LPF)and evaluated the application effect of LPF instead of traditional phenolic resin in bamboo and wood composite container floors.This study foucuses on the twice formaldehyde dosing ratio,water content and lignin replacement rate on the influence of viscosity of adhesive,internal strength,solid content,and free formaldehyde content.The optimal conditions of lignin phenol resin was used in bamboo and wood composite container floor to improve its elastic modulus,flexural strength,and other properties.Lignin phenolic resin was characterized by FTIR,DSC and SEM.The results show that:Under the optimal conditions of 30%lignin content of phenol,30 g water content for the second time,and 3:7 formaldehyde content,the bonding strength of LPF resin prepared under these conditions reached 10.14 MPa.The viscosity was 205.5 mPa·s(≤300 mPa·s).The content of free formaldehyde was 0.29%(≤0.3%),and the water resistance was good.The elastic modulus of the container floor reached 10245 MPa,which was 18.37%higher than that of the traditional PF resin.The addition of lignin is beneficial to improve the toughness of the adhesive and the elastic modulus of container bottom plate.