Structure and anisotropy in polycarbonate III. Study of elastic and optical properties of oriented samples with the method of high resolution Brillouin spectroscopy

Abstract

High resolution Brillouin spectroscopy (BS) has been used to investigate elastic and optical properties of uniaxially drawn samples of polycarbonate (PC). The results are discussed in the framework of the single phase aggregate model (SPAM) of Ward. According to a recently developed evaluation technique, the SPAM parameters of PC are determined, resulting in the following elastic constants of the structural units:c ⁰₃₃ =33 GPa,c ⁰₁₁ =7 GPa,c ⁰₁₃ =9.7 GPa,c ⁰₄₄ =1.4 GPa, andc ⁰₆₆ =1 GPa. A nearly quadratic dependence of the orientation parameterP ₄ onP ₃ results, which can be explained by a modified pseudoaffine deformation scheme.