低能量链端对聚苯乙烯薄膜铺展和润湿行为的影响

通过低能量功能端基的表面富集作用，研究了聚苯乙烯（ＰＳ）薄膜在聚甲基丙烯酸甲酯（ＰＭＭＡ）表面上的铺展和润湿动力学．用光学显微镜跟踪了ＰＳ薄膜的润湿行为，并对高分子熔体膜中非连续部分尺寸的增大速率进行了测定．分别用ＸＰＳ和ＡＦＭ对ＰＳ薄膜的表面组成和ＰＳ液滴的平衡接触角进行了测定．发现具有低表面能的氟碳端基在薄膜表面富集使ＰＳ薄膜的表面张力下降，并使ＰＳ液滴在ＰＭＭＡ表面上的平衡接触角减小，从而使高分子熔体膜中非连续部分尺寸的增长速率下降，得到了与液液界面铺展和润湿理论一致的实验结果．

THE EFFECT OF LOW ENERGY CHAIN END ON THE DEWETTING DYNAMICS OF POLYMER THIN FILMS

The dewetting dynamics of polystyrene(PS) blend thin films of low energy fluorocarbon chain end functional PS\|F 173K and PS\|F 355K with normal PS 345K on the 100K poly(methyl methacrylate)(PMMA) surface have been investigated.Optical microscopy was used to follow the dewetting process.XPS and AFM have been used to detect the surface segregation of fluorocarbon chain end at the surface and the equilibrium contact angle of PS droplet on PMMA.The surface segregation of low energy fluorocarbon chain end increases and the equilibrium contact angle of PS droplet decreases with increasing of the end functional polystyrene bulk fraction and decreasing of molecular weight.The segregation of fluorocarbon chain end to the surface makes the surface tension and equilibrium contact angle decrease.The dewetting velocity of PS films on PMMA was found to decrease as a function of the surface tension and equilibrium contact angle.It is in agreement with the theoretical prediction.\=