Iglesias JG, González-Benito J, Aznar AJ, Bravo J, Baselga J. Effect of Glass Fiber Surface Treatments on Mechanical Strength of Epoxy Based Composite Materials.
J Colloid Interface Sci 2002;
250:251-60. [PMID:
16290658 DOI:
10.1006/jcis.2002.8332]
[Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2001] [Accepted: 02/27/2002] [Indexed: 11/22/2022]
Abstract
Sizing glass fibers with silane coupling agents enhances the adhesion and the durability of the fiber/polymer matrix interface in composite materials. There are several tests to determine the interfacial strength between a fiber and resin, but all of them present difficulties in interpreting the results and/or sample preparation. In this study, we observed the influence of different aminosilanes fiber coatings on the resistance of epoxy-based composite materials using a very easy fractographic test. In addition, we tried a new fluorescence method to get information on a molecular level precisely at the interface. Strength was taken into account from two standpoints: (i) mechanical strength and (ii) the resistance to hydrolysis of the interface in oriented glass-reinforced epoxy-based composites. Three silanes: gamma-aminopropyltriethoxysilane, gamma-Aminopropylmethyldiethoxysilane, and gamma-Aminopropyldimethylethoxysilane were used to obtain different molecular structures at the interface. It was concluded that: (i) the more accessible amine groups are, the higher the interface rigidity is; (ii) an interpenetrating network mechanism seems to be the most important for adhesion and therefore to the interfacial strength; and (iii) the higher the degree of crosslinking in the silane coupling layer is, the higher the hydrolytic damage rate is.
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