造纸黑液木质素作为EPDM橡胶偶联剂的研究

采用硝酸和硫酸由碱法造纸黑液中酸析得到2种木质素，对其进行了粒径分布分析。研究了分别添加这2种木质素和硅烷偶联剂对三元乙丙橡胶（EPDM）性能的影响。结果表明，2种木质素具有较小的中位径和较大的比表面积，加入EPDM橡胶中，比硅烷偶联剂更能改善其力学性能；当加入1.5 %（基于100 g橡胶）硝酸盐木质素时，EPDM橡胶的拉伸强度、断裂伸长率和肖A硬度分别提高了21.42 %、 22.55 % 和8；傅里叶红外光谱分析（FTIR）和扫描电子显微镜（SEM）结果证实木质素对橡胶有补强作用；而热失重（TG）结果说明木质素和硅烷偶联剂一样均能提高EPDM橡胶的热稳定性；木质素替代硅烷偶联剂用于EPDM橡胶，可改善其性能，降低生产成本，有较好的应用前景。

Investigation on Lignins from Pulping Black Liquor as Coupling Agent for EPDM

Two types of lignins were obtained from alkaline pulping black liquors by acidulation using nitric acid and sulphuric acid, and their particle-size distributions were analyzed. A comparative investigation was conducted for the properties of ethylene-propylene-diene-monomer (EPDM) rubbers with the two types of lignins and silane-coupling agent. The results indicated that the two types of lignins exhitibted a smaller value of D50 and a bigger specific surface area. The incorporation of lignin-coupling agents improved the mechanical performances of EPDM rubber more significantly than the silane-coupling agent. The tensile strength, elongation at break and hardness of EPDM rubbers increased by 21.42 %, 22.55 % and 8 degree with the addition of 1.5 phr nitrate lignin (based 100 g rubber). The Fourier-transform infrared spectroscopy (FTIR) analysis and scanning electron microscopic (SEM) observation indicated that the lignins played a role in the reinforcement of EPDM rubber. Thermogravimetric analysis revealed that the lignins and silane-coupling agents improved the thermal stability of EPDM rubbers. The lignins could be used to replace the silane-coupling agent for modification of EPDM rubbers in a cost-effective way and therefore exhibited good application potential.