Dielectric properties dependent on crystalline morphology of PP film for HVDC capacitors application

Dielectric properties dependent on crystalline morphology of PP film for HVDC capacitors application

In this paper, the effects and mechanism of crystalline morphology on dielectric loss and breakdown strength of PP film were studied. The crystalline morphology was modified by adding the β-nucleating agent (β-NA). The crystalline types and crystalline morphologies of samples were analysed by the X-...

Full description

Saved in:
Bibliographic Details
Published in:Polymer (Guilford) 2021-01, Vol.213, p.123204, Article 123204
Main Authors: Xu, R.R., Du, B.X., Xiao, M., Li, Jin, Liu, H.L., Ran, Z.Y., Xing, J.W.
Format: Article
Language:eng
Subjects:
Breakdown strength
Conductivity
Crystal structure
Crystalline morphology
Crystallinity
Dielectric breakdown
Dielectric loss
Dielectric properties
Dielectric strength
Electrical properties
Energy distribution
Energy levels
HVDC capacitors
Light microscopy
Morphology
Optical microscopy
Polypropylene film
Reagents
Spherulites
X-ray diffraction
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this paper, the effects and mechanism of crystalline morphology on dielectric loss and breakdown strength of PP film were studied. The crystalline morphology was modified by adding the β-nucleating agent (β-NA). The crystalline types and crystalline morphologies of samples were analysed by the X-Ray diffraction (XRD) and the polarized optical microscopy (POM), respectively. The current integration, representing the dielectric loss, was investigated using the Q(t) method. The DC conductivity was measured at temperature from 25 to 85 °C. The effects of crystalline morphology on the trap energy level distribution were analysed by the isothermal discharge current (IDC). The DC breakdown strength was tested using a pair of ball-plate electrodes at 85 °C. The results of XRD and POM indicate that the addition of β-NA introduced β-spherulites in PP film and the spherulite size of samples with β-NA are smaller the spherulites size of PP without β-NA. The results of IDC indicate that the special structure of β-spherulites introduced deep trap energy levels. The results of Q(t) and DC conductivity indicate that β-spherulites can effectively suppress the current though samples. Besides, the addition of β-nucleating agent increases the DC breakdown strength at 85 °C. [Display omitted] •Improved dielectric properties by modulating the crystalline morphology.•Applied current integration Q(t) method to analyze the dielectric loss of samples.•Obtained the effect of crystalline morphology on dielectric properties of PP film.
ISSN:0032-3861
1873-2291