Surface Photografting Initiated by Benzophenone in Water and Mixed Solvents Containing Water and Ethanol
Surface Photografting Initiated by Benzophenone in Water and Mixed Solvents Containing Water and Ethanol
复制标题
DOI：
10.1002/app.34683
复制
发表时间：
2012-02-15
影响因子：
3
通讯作者：
Wang, Huiliang
中科院分区：
文献类型：
--
作者：
Li, Guangwu;He, Guanyang;Wang, Huiliang
由于二苯甲酮（BP）等光引发剂的水不溶性，光接枝反应通常在有机溶剂中进行。本文报道了水和水与乙醇的混合溶剂对BP引发聚乙烯表面光接枝甲基丙烯酸（MAA）的影响。接枝率随混合溶剂中水体积比的增加而增加，BP在纯水溶剂中的光引发效率最高。研究了BP浓度、单体浓度和单体种类对光接枝的影响。接枝率在纯水溶剂中的BP浓度（0.20 mol/mol %）比在具有90 v/v %水的混合溶剂中的BP浓度（0.60 mol/mol %）低时显示出最大值。接枝率随单体浓度的增加先增加后下降，当单体浓度为3 mol L-1时，接枝率随单体浓度的增加先增加后下降。在混合溶剂中，丙烯酸（AA）也可以通过BP光接枝到聚乙烯上。紫外-可见光谱研究表明，随着水体积比的增加，BP的π-π * 跃迁λ（max）发生位移，即，溶剂的极性。在极性较大的溶剂中，紫外光激发BP所需的能量较少，更容易引发接枝反应。(C)2011 Wiley Periodicals，Inc.应用聚合物科学杂志123：1951-1959，2012
Photografting reactions are usually carried out in organic solvents due to the water insoluble nature of photoinitiators such as benzophenone (BP). This work reports the effect of water and mixed solvents containing water and ethanol on the surface photografting of methacrylic acid (MAA) onto polyethylene initiated by BP. The percent grafting increased with the increase of water volume ratio in the mixed solvent, and BP showed the highest photoinitiation efficiency when dissolved in pure water solvent. Effects of BP concentration, monomer concentration, and monomer type on photografting were studied. The percent grafting showed the maximum at a lower BP concentration (0.20 mol/mol %) in pure water solvent than that (0.60 mol/mol %) in the mixed solvent with 90 v/v % water. The percent grafting first increased with the increase of monomer concentration till 3 mol L-1 and then decreased. Acrylic acid (AA) could also be photografted onto polyethylene by BP in the mixed solvents. UV-visible spectroscopic examinations revealed that the lambda(max) of pi-pi* transitions of BP red shifted as the increase of the water volume ratio, i.e., the polarity of the solvent. The excitation of BP in solvents with a higher polarity under UV irradiation requires less energy, so the photografting initiated by BP is easier to occur. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1951-1959, 2012