Effect of hydrogen bonding on micro-mechanical properties of high performance organic fibers
Organic fibers pose a viable alternative as reinforcement for weight-sensitive, high performance applications requiring high specific tensile strength and energy absorption. However, the compressive properties of organic fibers are still lower than the values observed for glass and carbon. The reason for the limited compressive performance of the organic fibers is their fibrillar structure, in which the lack of strong lateral support between fibrils gives way to failure at rather moderate compressive loads. Despite the relevance of lateral interactions on fiber mechanical properties, there is not a reliable method to measure and quantify the effect of hydrogen bonding on fiber mechanical properties. In this project, novel micro-mechanical techniques are being developed in order to identify the effect of intermolecular interactions on fiber properties such as axial compressive modulus, transverse modulus and shear modulus. Fibers with varying degrees of hydrogen bonding are obtained by manipulating the annealing conditions, and the formation of hydrogen bonds is monitored using spectroscopic techniques. With this, the relations between hydrogen bonding, fiber microstructure and mechanical performance are clearly identified, providing a way to advance our understanding of the mechanisms governing fiber failure.
A. Leal, J. M. Deitzel, J. W. Gillespie, Jr., Mechanical properties and surface characteristics of novel high-performance organic fibers. Proceedings, International SAMPE Symposium and Exhibition 48, 793-803 2003
A. Leal, J. M. Deitzel, J. W. Gillespie, Jr., Micro-mechanical properties of novel organic fibers. 2005 Fiber Society Fall Annual Meeting and Conference-oral presentation