Solvent effects in the polyethylene terephthalate surface modification by cold argon plasma‐induced grafting polymerization of methacrylic acid

We studied the surface modification of polyethylene terephthalate (PET) by grafting with methacrylic acid (MAA) through plasma‐induced polymerization method. The results show that the grafting yield increases with the increase of reaction temperature. The grafting yield is in proportion to the increase of monomer concentration. The grafting yield increases along with the prolonging of reaction time. The solvent has great influence to the grafting reaction. The grafting yield increases with the increase of volume ratio R, which is defined by the volume of water to the volume of alcohol, when using alcohol and water as mixed solvent. The grafting yield is not zero when only using methanol, ethanol or isopropanol as the solvent. The red shift in UV spectrum could be ascribed to different reactive activities of MAA in different solvents, which also can explain the change trend of the grafting yield. The UV‐vis absorbance difference and the FTIR integrated peak area of the C?O stretching increase steadily with the increase of grafting yield, which are almost linear relationship. It was confirmed that MAA was grafted onto the PET surface in terms of UV‐vis spectrophotometric, FTIR and atomic force microscopy analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010