N,N-二乙基丙烯酰胺与丙烯酸在聚丙烯薄膜表面光接枝制备二元接枝膜及其温度、pH值敏感特性研究

PREPAREATION AND CHARACTERIZATION OF N,N-DIETHLYLACRYLAMIDE AND ACRYLIC ACID BINARY MONOMERS-GRAFTED POLYPROPYLENE FILMS WITH TEMPERATURE-AND pH-SENSITIVITIES

以二苯甲酮为引发剂,聚丙烯薄膜(CPP)为基材,通过紫外光接枝的方法制备了具有温度和pH值双重敏感特性的聚N,N-二乙基丙烯酰胺(PNDEA)与聚丙烯酸(PAA)二元接枝膜.在PNDEA一次接枝膜的制备过程中,引发剂与单体配比相同时,本体接枝方法的接枝速率在反应初期明显高于溶液接枝方法;采用溶液法时,增大引发剂与单体配比等可提高接枝率.用本体法所制得的PNDEA一次膜光活化接枝PAA时接枝速率较溶液法高,并且能够实现较高的PAA接枝率.用红外光谱(FTIR)、X射线光电子能谱化学分析(ESCA)对接枝层组成的表征结果证实了二元接枝层的存在.在不同温度下,PNDEA一次接枝膜的FTIR谱图中酰胺Ⅰ带特征吸收峰发生位移表明它具有温度敏感特性.用扫描电子显微镜(SEM)对PNDEA接枝层表征结果表明,用不同接枝手段所制备的接枝膜具有不同的表面形貌.通过吸水率测定研究了二元接枝膜的温度及pH值敏感特性.

Binary monomers-grafted films with temperature- and pH-sensitivities were prepared by photo-grafting of N, N-diethyl-acrylamide and acrylic acid onto polypropylene films with benzophenone （BP） as an initiator. At the beginning of the process preparing PNDEA grafted films, the grafting rate of photo-grafting in bulk was higher than that in solution. Increasing the mole ratio of initiator to monomer could increase the grafting yield by photo-grafting in solution. The grafting yield and the grafting rate of PAA can be much higher when PNDEA grafted films were prepared by photo-grafting method in bulk. The existence of PNDEA and PAA binary grafted layer was confirmed by FTIR and ESCA measurements. The acrylamide band I in FTIR spectra of the PNDEA grafted layer shifted as the temperature changed, which revealed the temperature sensitivity of the grafted films. The SEM images of the PNDEA grafted layers prepared by different grafting methods have different surface morphology. The temperature- and pH- sensitivity of the binary monomers-grafted films were also studied by the measurement of water absorbency.