Wood Adhesive Bondlines by Nanoindentation
The mechanical properties of both the adhesive and interphase cell walls in wood adhesive bonds were determined by nanoindentation. Seven different polymers used frequently as adhesives and/ or matrix polymers in wood, wood composites, and natural fibre reinforced composites were studied by nanoindentation (Konnerth et. al ) and compared with results from previous uniaxial tensile tests (Konnerth et. al ). It was shown that the elastic modulus, the hardness, the creep factor, and the elastic-, plastic-, and viscoelastic work of indentation of the seven different polymers is essentially the same regardless whether the polymers were tested in the form of pure films or in-situ, i.e. in an adhesive bond line with spruce wood. An excellent correlation was found between the elastic modulus measured by tensile tests and the elastic modulus measured by nanoindentation. In spite of the good correlation, the elastic modulus measured by nanoindentation is significantly higher than the elastic modulus measured by tensile tests.
KeywordsFormaldehyde Polyurethane PVAc
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