Crystallization and Dielectric Properties of MWCNT /Poly(1-Butene) Composite Films by a Solution Casting Method.

Lingfei Li,Yongjun Xu,Zhaohua Jiang,Xiangqun Chen,Qiu Sun

doi:10.3390/ma13030755

Abstract

In this work, poly(1-butene) (PB-1) composite films with multi-walled carbon nanotubes (MWCNT) were prepared by a solution casting method. The relationship between the dielectric properties and the crystal transformation process of the films was investigated. It was indicated that there were two crystal forms of I and II of PB-1 during the solution crystallization process. With the prolongation of the phase transition time, form II was converted into form I. The addition of the conductive filler (MWCNT) accelerated the rate of phase transformation and changed the nucleation mode of PB-1. The presence of crystal form I in the system increased the breakdown strength and the dielectric constant of the films and reduced the dielectric loss, with better stability. In addition, the dielectric constant and the dielectric loss of the MWCNT/PB-1 composite films increased with the addition of MWCNT, due to the interfacial polarization between MWCNT and PB-1 matrix. When the mass fraction of the MWCNT was 1.0%, the composite film had a dielectric constant of 43.9 at 25 °C and 103 Hz, which was 20 times that of the original film.

Highlights

Energy storage film capacitors have become a focus for all over the world, due to the increasing depletion of fossil fuels and the growing environmental issues [1,2]
multi-walled carbon nanotubes (MWCNT)/PB-1 composite films, the contents of MWCNT ranged from 0.25 wt% to 2.0 wt%, and the and theIncomposite film samples with a phase transition time ofthe240 h were characterizedof by X-ray diffraction (XRD), order to further study effect transition of MWCNT
The results showed that the addition of MWCNT caused addition of caused a slight increase in the tan δ of the MWCNT/PB-1 composite film, and a slight increase in the tan δ of the MWCNT/PB-1 composite film, and the polarization loss increased the to polarization loss increased duebetween to the interfacial polarization the MWCNT and the PB-1 due the interfacial polarization the MWCNT

Summary

Introduction

Energy storage film capacitors have become a focus for all over the world, due to the increasing depletion of fossil fuels and the growing environmental issues [1,2]. Biaxially-oriented polypropylene (BOPP) films (ε’ = 2.2, Ud < 2 J·cm−3 ) are commonly used in capacitors. (PB-1) has a dielectric constant of 2.53 and a dielectric loss of 0.0005 at 103 Hz [9]. What is more, it has better mechanical properties, chemical stability, and good creep resistance at high temperatures (100 ◦ C) [10], which can be used as a diaphragm for a storage capacitor

Methods

Results

Conclusion