(530e) Nanomechanical Properties of Poly(para-phenylene vinylene) Determined Using Quasi-Static and Dynamic Nanoindentation

Mechanical properties of poly(p-phenylene vinylene) (PPV) conjugated polymer were determined by quasi-static and dynamic nanoindentation [1]. PPV films were prepared by thermolytic conversion of poly[p-phenylene (tetrahydrothiophenium)ethylene chloride] precursor films, at different temperatures. The mechanical properties of the films showed a dependence on the extent of conversion and chemical composition of the films. The storage modulus, E_r', and plasticity decreased with an increase in conversion, whereas the loss modulus, E_r", showed the opposite trend. Both the precursor and the fully-converted PPV films were found to have significantly lower E_r" than E_r', consistent with the glassy nature of the polymers at room temperature. The fully-converted PPV polymer was found to have room-temperature loss and storage moduli of 0.2 and 4.4 GPa, respectively. A comparison of the contact mechanical properties of the isotropic PPV films synthesized in this work, with the results of molecular dynamics simulations, and with previously reported values for stretch-oriented anisotropic films determined by conventional tensile testing methods, will also be discussed.

[1] Sreeram, A.; Patel, N. G.; Venkatanarayanan, R. I.; McLaughlin, J. B.; DeLuca, S. J.; Yuya, P. A.; Krishnan, S. Nanomechanical properties of poly(para-phenylene vinylene) determined using quasi-static and dynamic nanoindentation, Polymer Testing, In press. DOI: 10.1016/j.polymertesting.2014.04.012.