以棉杆木质素(LG)为原料,制备尿素基改性棉杆木质素(UM-LG)、酯化木质素(EL)、间苯二胺基改性棉杆木质素(ML)等三种改性棉杆木质素,并作为聚合物改性剂,添加到聚丙烯(PP)中,研究不同改性木质素对PP阻燃和抗氧化性能的影响。结果表明：三种改性木质素对PP的阻燃和抗氧化性能都有所提升。PP中添加15wt% UM-LG后,与纯PP试样比较氧化诱导时间提高52.9%；在200℃、螺杆转速30r/min、回流10min条件下剪切扭矩提高50.58%。当PP中添加15wt% ML后氧指数达到了24.9%,SEM图中可以发现三种改性木质素的添加使得PP在燃烧过程中形成了炭层,进一步说明了改性木质素增强了PP的阻燃性能。力学性能测试表明：随着的改性木质素的添加,PP的力学性能受到一定程度的影响。
Using cotton stalk lignin (LG) as raw material, three kinds of urea-based modified cotton stalk lignin (UM-LG), esterified lignin (EL) and m-phenylenediamine-based modified cotton stalk lignin (ML) were prepared. A modified cotton stalk lignin was added to polypropylene (PP) as a polymer modifier to study the effects of different modified lignins on the flame retardant and antioxidant properties of PP. The results showed that the three kinds of modified lignin improved the flame retardant and antioxidant properties of PP. After adding 15wt% UM-LG to PP, the oxidation induction time was increased by 52.9% compared with the pure PP sample; the shear torque was increased by 50.58% at 200 °C, screw speed 30 r/min, and reflux for 10 min. However, after adding 15wt% ML to PP, the oxygen index reached 24.9%. It can be found in the SEM image that the addition of three modified lignins made PP form a carbon layer during the combustion process, which further demonstrated that the modified lignin enhanced the PP Flame retardant properties. The mechanical properties test showed that: with the addition of modified lignin, the mechanical properties of PP were affected to a certain extent.