Abstract: Radical scavenging ability of a novel intramolecular complex antioxidant towards 1,1-diphenyl-2-picrylhydrazyl (DPPH?) free radical was studied by uv-vis spectrophotometer，and compared with that of antioxidant BHT and antioxidant 1076. Results showed that the radical scavenging ability of the novel intramolecular complex antioxidant was superior to that of commercial antioxidants BHT and 1076. The scavenging ability increased with the increase of the concentration of the antioxidant，and the scavenging ability increased first and then kept constant afterwards. Temperature has little influence on the reaction rate，which showed that activation energy was lower and this reaction can proceed rapidly at room temperature. The antioxidation performance for polyethylene was evaluated by melt flow rate and oxidation induction time. Results also showed that the antioxidant ability of the synthesized complex antioxidant was superior to the commercial antioxidant BHT and 1076.

Key words: 1,1-diphenyl-2-picrylhydrazyl free radical, intramolecular complex antioxidant, radical scavenging, oxidation induction time

摘要： 以DPPH?为研究对象，采用紫外-可见光分光光度计研究了新型分子内复合抗氧剂对自由基的清除能力，并与市售抗氧剂1076和BHT进行对比。结果表明，相同条件下，该新型分子内复合抗氧剂清除自由基的能力优于市售抗氧剂1076和BHT；且清除自由基的能力随抗氧剂浓度的增加而增大，随清除反应时间的延长先增大后趋于稳定。清除反应温度对清除能力影响不大，表明该清除反应的反应活化能较低，该清除反应可在室温下快速进行。熔体流变速率和氧化诱导期测得的结果也证实了新型分子内复合抗氧剂的抗氧化能力优于市售抗氧剂BHT和1076。

关键词: DPPH自由基, 分子内复合抗氧剂, 清除自由基, 氧化诱导期