Terahertz dielectric spectroscopy based thermal‐oxidative aging analysis of polyvinyl chloride

Abstract Polyvinyl chloride (PVC) is a polymer widely used in the world whereas safety problems owing to PVC aging are often reported. Thermal‐oxidative aging is known the main cause of its performance deterioration and lifetime decreasing. The existing PVC aging detection methods are complicated, making it difficult to achieve rapid on‐site diagnosis. The purpose of this paper is to evaluate the degree of PVC aging by means of terahertz technology. Samples were subject to thermal‐oxidative aging, and the corresponding dielectric spectra were measured by a terahertz time‐domain spectrometer. It turns out that the aging dependent dielectric spectra conforms to the physicochemical theory. Moreover, numerical correlation between the change in permittivity and the degree of aging, underlying a new solution for the aging forecast aimed at plastics.