改性木粉/碱木质素在橡胶中的应用研究

Study on application of modified wood powder/alkali lignin in wood/rubber composite

为提高木材附加值及制浆造纸废液中碱木质素的利用率,以木粉、碱木质素为填料,未硫化胎面橡胶为基体,采用橡胶机械混炼-硫化工艺制备了生物质/橡胶复合材料。研究了Si69改性木粉与碱木质素的不同配比对复合材料理化性能的影响,并对复合材料的力学性能、硫化性能、门尼黏度、微观界面和动态力学性能进行了表征。结果表明:改性木粉与碱木质素作为填料制备的橡胶复合材料,其物理性可满足工业用橡胶板国家标准GB 5574—2008使用要求。当改性木粉与碱木质素质量比为2∶1时,复合材料拉伸强度最大,为4.6 MPa;当改性木粉与碱木质素质量比为1∶2时,断裂伸长率最高,为778%。复合材料的门尼黏度以及硫化时间随碱木质素含量的增多而增大。加入碱木质素降低了复合材料的动态储能模量,且加入过多的碱木质素导致复合材料的玻璃化转变温度升高,而玻璃化温度的升高使得橡胶的最低工作温度升高。

The objective of this study was to utilize low value wood and alkali lignin from pulping black liquor as fillerin value-added biomass/rubber composites. The composites were prepared by mechanical mixing and vulcanizing ofwood flour and alkali lignin as filler and unvulcanized tire rubber as the matrix. The effects of Si69 modification ofwood powder and alkali lignin at different ratios on the physical and chemical properties, mechanical properties, cu-ring properties, mooney viscosity, micro interface and dynamic mechanical properties of the resulting composites wereinvestigated. The results showed that the mechanical properties and hardness of the composites reached the requirementof the national industrial rubber standard （ GB 5574--2008）. When the ratio of Si69 modified wood powder to alkalilignin was 2 ： 1, the tensile strength reached the maximum value of 4. 6 MPa. When the ratio of Si69 modified woodpowder to alkali lignin was 1：2, the elongation at break reached the maximum value of 778%. The curing time andmooney viscosity of the composites increased as the straw powder content increased. The incorporation of alkali ligninreduced the dynamic storage modulus of the composites, but that of excess lignin increased the glass transition temper-ature of the composites, which could lead to the increase of the minimum working temperature of rubber.