Estimation of the strength of microfibers in polymer fibrillar materials

A unique method was advanced for estimating the strength of fibrillar sampl es on the basis of the corresponding tensile force-elongation curves. This method relies on the statistical analysis of the combined data of optical m icroscopy and mechanical tests. As compared to the well-known "dry bundle" method, the approach advanced to estimate strength does not require any dat a on the elastic modulus of fibers. This approach allows one to calculate t he strength of a polymer for porous-fibrillar samples composed of microfibe rs with different diameters (1-20 mum) containing branching junctions rando mly distributed in the sample at a distance of similar to0.1-2 mm and formi ng a loosened network with elongated cells. This approach might appear to b e useful for the estimation of the strength of monofilaments not only for c ellular fibrillar materials hut also for systems with unbound fibers when, for any reason, a direct estimation of the strength of monofilaments is imp ossible.