Dependence of surface free energy on molecular orientation in polymer films

Surface free energy of mechanically drawn polycarbonate films was determined using contact angle measurements and shown to increase with orientation. The increase in polymer film surface free energy was attributed to increased polymer chain packing during orientation, supported by film density measurements, which provides enhanced intermolecular interactions. Surface free energy can therefore be increased by, or used to predict, polymer orientation. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3691186]