Simultaneous measurement of optical and dynamic mechanical properties of plastic optical fibers

Dynamic mechanical analysis (DMA) is one of the most powerful tools to study the behavior of plastic and polymer composite materials and it is a potentially very useful tool to simulate behavior of plastic optic fibers (POF) in real applications. The possibility of simultaneous measurements of some optical properties during DMA would significantly upgrade investigations of POF alone or embedded in some materials. In this work, single cantilever DMA of the POFs that was done simultaneously with measuring the transmitted optical signal intensity is described and discussed. In order to compare mechanical results of the same material for cylindrical and rectangular specimens, rectangular plates were prepared by melting POFs and the same kind of tests were performed. It is shown that changes of the optical signal intensity correspond to the changes of storage modulus of the POF during DMA, and the maximums in optical signals intensity indicate the beginning of glass transition processes in the POF material.