Electrical degradation of blends and laminar composites of polyethylene and polystyrene

Abstract

Physical blends and laminar composites of polystyrene (PS) and polyethylene (PE) were prepared with and without a tri‐block copolymer compatibilizer (poly(styrene‐block‐(ethylene‐co‐1‐butene)‐block‐styrene)), denoted SEBS. Dielectric strength and breakdown time of samples exposed to external partial discharges (PD) were measured and relationships were sought with composition, phase morphology, and phase bonding. The polymers were selected because they are incompatible and because the dielectric strength and stability towards PD are greater for PS than for PE. It was shown by adding small quantities of SEBS that a minimum amount of cohesive forces between the components was required to achieve good electrical properties. The major morphological factor controlling the electrical stability was which polymer constituted the continuous phase. Laminar composites with continuous sheets of stable PS as a top layer exhibited a stability equal to or better than that predicted from the upper bound rule of mixing.

Dielectric properties of isotactic polypropylene/nitrile rubber blends: Effects of blend ratio, filler addition, and dynamic vulcanization

“…Figure 1 shows the variation of volume resistivity ( v ) of PP/NBR blends as a function of NBR concentration. PP is a good insulator, with a volume resistivity in the order 10 16 ⍀ cm, whereas the volume resistivity of nitrile rubber is in the order of 10 10 ⍀ cm. In the case of blends the v has intermediate values in between that of PP and NBR.…”

Effects of CaTiO3 Loading on the Properties of PTFE/TiO2 Composites

“…The dielectric properties of the substrate composites depend on not only the dielectric properties of the components but also other factors such as the interactions between ceramics and polymers, the size of fillers, and the dispersion of fillers in polymer matrix [8] [9] [10]. Figure 6 shows the dielectric constant and dielectric loss of the composites as a function of CaTiO 3 loading percent.…”

Dielectric properties of natural rubber/chitosan blends: Effects of blend ratio and compatibilization

“…Most of the polymers are excellent insulating materials and they are less susceptible to conduction by imperfection and structural irregularities, which made them an attractive choice for electrical applications. Electrical properties of various polymer blends have been investigated by different researchers [2][3][4][5][6][7][8]. In these reports it has been shown that the dielectric properties of polymers and blends in general depend on structure, crystallinity, morphology and presence of fillers or other additives.…”