Effects of Stoichiometry and Epoxy Molecular Mass on Wettability and Interfacial Microstructures of Amine-Cured Epoxies

Published

February 1, 2001

Author(s)

M Giraud, Tinh Nguyen, Xiaohong Gu, Mark R. VanLandingham

Abstract

The effects of stoichiometry and epoxy molecular mass on surface and interfacial microstructures and wettability of amine-cured epoxies have been investigated. Thin (150 m) amine-cured epoxy films were prepared by reacting epoxy resins having sixdifferent equivalent epoxide masses ranging from 185 g to 3050 g with a polyoxyalkyleneamine curing agent at three different stoichiometries. The microstructures of the film/air and film/silicon substrate interfaces were measured by atomic force microscopy (AFM) in the tapping mode using both phase and topographic imaging techniques. Cross-sectional interphases between the epoxy films and steel substrate were characterized by AFM. Surface free energy, surface polarity, work of adhesion, and acid-base parameters of the film surfaces were calculated using contact angles of water, methylene iodide, and formamide liquids. All amine-cured epoxy films show a two-phase microstructure consisting of nodular domains surrounded by a matrix. Both the molecular mass and stoichiometry have a strong influence on the size of the nodular domains of both the film/air and film/substrate interfaces. However, both the molecular mass and stoichiometry had only a small effect on the wettability parameters.

Proceedings Title

24th Annual Meeting of the Adhesion Society

Conference Dates

February 25-28, 2001

Conference Title

Adhesion Society

Pub Type

Conferences

Keywords

epoxy molecular mass, stoichiometry

Citation

Giraud, M. , Nguyen, T. , Gu, X. and VanLandingham, M. (2001), Effects of Stoichiometry and Epoxy Molecular Mass on Wettability and Interfacial Microstructures of Amine-Cured Epoxies, 24th Annual Meeting of the Adhesion Society (Accessed December 5, 2024)