Oleophilic modification of poly(vinyl alcohol) films by functionalized soybean oil triglycerides

In this study, maleinized (SOMAP) and isocyanated soybean oil (SONCO) triglycerides have been successfully grafted onto one surface of poly(vinyl alcohol)(PVA) films to give films that are hydrophilic on one side and hydrophobic on the other. The surface grafting was accomplished by the reaction of succinic anhydride or isocyanate functionalities of soybean oil derivatives and the hydroxyl groups of PVA films. The reaction was run in toluene, using PVA films on glass slides so that only one side of the film was accessible. After grafting, the films were rinsed with hot toluene to remove ungrafted triglycerides from the surface. The reaction on the surface was confirmed by ATR‐FTIR and ¹H‐NMR spectroscopic techniques. A series of films were prepared at different concentrations of SOMAP or SONCO in toluene. The increase in hydrophobicity with an increase in SOMAP or SONCO concentrations was observed by water contact angle measurements. The contact angles on the grafted side of the film reach their maximum value of 88° and 94° for 26 and 2.5% SOMAP and SONCO concentrations in toluene, respectively, while the ungrafted side gives contact angle of 48°. Surface morphologies of PVA‐g‐SOMAP and PVA‐g‐SONCO films were investigated by atomic force microscopy, whereas optical microscopy and staining was used to determine the homogeneity of the films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011