2,2,6,6-四甲基哌啶-1-氧自由基对低温等离子辐射聚氨酯膜表面过氧自由基的研究

Study on the superoxide radicals of PU surface radiated by plasma with the 2,2,6,6-Tetramethyl-1-piperidinyloxyl radical method

采用2,2,6,6-四甲基哌啶-1-氧自由基(2,2,6,6-Tetramethyl-1-piperidinyloxyl radical,TEMPO)法,测定了经氧气低温等离子体处理后聚氨酯膜表面过氧自由基的浓度,探讨了等离子轰击时间、等离子放电功率、在空气中放置时间等因素对等离子体处理后自由基浓度的影响。在经测定获得的自由基浓度较高的条件下,引发聚氨酯与丙烯酸的接枝聚合,验证了TEMPO法的可行性,讨论了聚合时间对接枝率的影响。丙烯酸在聚氨酯膜表面的接枝共聚由扫描电子显微镜得到确认。在等离子放电功率为600W,放电时间为180s时所测定的自由基浓度最高,相应的接枝率较高。实验结果表明,TEMPO法是一种有效的测定自由基浓度的方法。

ha this study, the quantity of the superoxide radicals created by O2 plasma activation was confirmed by a new method-the 2,2,6,6-Tetramethyl-l-piperidinyloxyl radical （TEMPO） method and the effects of various conditions on radicals concentration were investigated. Under the conditions at which the radicals have optimal concen- tration, polyurethane （PU） film was treated by plasma to graft with Acrylic acid （AA） in order to testify the feasibility and dependability of the TEMPO method. In addition, the influences of react conditions on grafting rate were discuss, the acrylic acid grafted on the surfaces was characterized by Scanning electron microscopy （SEM）. At 600W, 180s the concentration of the radicals high, the grafting rate is high correspondingly. The results suggest that the TEMPO method is an effective method to determine the concentration of superoxide radicals.