不同抗氧剂体系在聚碳酸酯中的应用对比

Comparison of application of different antioxidants in polycarbonate

聚碳酸酯(PC)在加工和使用过程中会发生老化现象从而影响其使用性能,通常加入抗氧剂可以抑制或延缓其老化。为了选择适用于PC的抗氧剂体系,选用三种主抗氧剂分别与辅助抗氧剂168复配使用于PC中,并采用多次挤出老化和热氧老化对其进行老化处理,分析了抗氧剂对PC性能的影响,研究了在加工老化和热氧老化过程中抗氧剂体系对PC老化的抑制效果和抗氧剂体系与色粉的配伍性,从而筛选出适用于PC的抗氧剂体系。结果表明,1790抗氧剂体系使PC初始颜色黄化,严重影响了产品的外观色泽;245抗氧剂体系对PC的初始颜色、光学性能和力学性能影响较小,但在加工老化和热氧老化过程中黄化速度较快,这会对产品的外观颜色产生不利影响;1076抗氧剂体系对PC的初始颜色、光学性能和力学性能影响较小,并且在加工老化和热氧老化过程中对PC有较好的保护作用;辅助抗氧剂168对PC初始性能影响较小,但过多的用量在加工老化和热氧老化过程中会使熔体流动速率升高,拉伸性能下降,应严格控制其用量;245抗氧剂体系和1076抗氧剂体系与色剂复配均具有较好的协同效应。抗氧剂1076体系较适用于PC。

Polycarbonate(PC)undergoes aging during processing and use,which affects its performance.Generally,adding antioxidants can inhibit or delay its aging.In order to select an antioxidant system suitable for PC,three main antioxidants were mixed with auxiliary antioxidant 168 and tested in PC.Multiple extrusion aging and thermal oxidative aging were used to age the PC,and the effect of antioxidants on its performance was analyzed.The inhibitory effect of antioxidant system on PC aging during processing aging and thermal oxidative aging,as well as the compatibility between antioxidant system and color powder were studied to screen the antioxidant system suitable for PC.The results show that the 1790 antioxidant system causes the initial yellowing of PC,which seriously affects the appearance and color of the product.The 245 antioxidant system has little effect on the initial color,optical properties,and mechanical properties of PC,but the yellowing rate is fast during processing aging and thermal oxygen aging,which is not conducive to the appearance color of the product.The 1076 antioxidant system has little effect on the initial color,optical properties,and mechanical properties of PC,and has a good protective effect on PC during processing aging and thermal oxygen aging processes.The effect of auxiliary antioxidant 168 on the initial performance of PC is relatively small,but excessive dosage can increase the melt index and decrease the tensile performance during processing aging and thermal oxygen aging.Therefore,its dosage should be strictly controlled.The 245 antioxidant system and the 1076 antioxidant system have good synergistic effects when combined with colorants.The antioxidant 1076 system is more suitable for PC.