Dielectric, Thermal and Mechanical Properties of a Sequence-regulated Ethylene/Anisylpropylene Copolymer

Abstract

The copolymerization of ethylene and anisylpropylenes by a sterically demanding half-sandwich scandium catalyst afforded an entirely new class of copolymers with a wide range of glass-transition temperatures (Tg) and mechanical, self-healing, and shape-memory properties by controlling the comonomer sequence and polymer molecular weight and varying the anisyl substituents. This paper focuses on the dielectric, thermal and mechanical properties of one representative of this class of copolymers to investigate its potential for use in electrical insulation technology. Dielectric, thermal and mechanical properties were comprehensively evaluated for the above copolymer. Besides estimating volume and surface resistivity and dielectric strength, the temperature and frequency dependence of the relative permittivity and loss factor were studied. Tg was also determined by differential scanning calorimetry. Tensile tests assessed mechanical and self-healing properties. The tested copolymer has excellent dielectric parameters that can be compared with commonly used insulating materials. Below the observed T g , the material also shows satisfactory electrical insulation properties in the frequency domain. The results of tensile tests show that the copolymer's stress-strain curve has a typical trend for thermoplastic polymers. In the range of elastic deformations, the material offers non-autonomous self-healing properties.