SOME REFLECTION ON THE EVALUATION OF THE LEWIS ACID-BASE PROPERTIES OF POLYMER SURFACES BY WETTING MEASUREMENTS

The letter underlines the need for a reflection and a debate on the qu antitative results arising from the application of current theories on the calculation of acid-base properties of polymer surfaces from wett ing measurements, To this end, published results on the Lewis acid-bas e properties of poly(methylmethacrylate) (PMMA) and of poly(vinylchlor ide) (PVC), as evaluated by the application of the Fowkes (work of adh esion; Fowkes, F. M., in ''Surface and Interfacial Aspects of Biomedic al Polymers'' (J. D. Andrade, Ed.), Vol. 1 Chap, 9. Plenum Press, New York, 1985) and Good-Van Oss-Chaudury (electron donor-electron accepto r components; Good, J. R., and van Oss, C. J., in ''Modern Approach to Wettability: Theory and Application'' (M. E. Schrader and G, Leed, Ed s,), Chap, 1, Plenum Press, New York, 1991) approaches to interfacial energetics, are compared, The former approach indicates the basic char acter of PMMA and the acidic nature of PVC surfaces. When the componen ts of the solid surface free energy are calculated according to the Go od-Van Oss-Chaudury theory, both surfaces appear overwhelmingly basic, PMMA being a stronger base than PVC, Data are compared to published r esults on the acid-base nature of PMMA and PVC, as evaluated by experi ments not based on wetting measurements, The need for a more complete understanding of the quantitative aspects of the wetting-measurement-b ased approaches to Lewis acid-base interfacial interactions is stresse d. (C) 1996 Academic Press, Inc.