Effect of Impregnated Phenolic Resins on the Cellulose Membrane for Polymeric Insulator

Sharifah Nurul Ain Syed Hashim,Zalita Zainuddin,Sharifah Nabihah Syed Jaafar,Sarani Zakaria,Thomas Rosenau,Chin Hua Chia

doi:10.3390/membranes12020106

Abstract

In this study, a cellulose membrane (CM) was chemically treated with phenolic (PF) resin to improve its performance as a polymeric insulator. The CM was prepared from kenaf pulp, and the PF was synthesized from oil palm empty fruit (EFB) fibre. Four different concentrations of synthesized PF resin (5, 10, 15, and 20 wt.%) were impregnated under wet or dry conditions. Thermal analysis of the phenolic cellulose membrane (PCM) showed that the samples had good chemical interaction and compatibility. The PF uptake in the wet phenolic cellulose membrane (PCMW) was higher than in the dry phenolic cellulose membrane (PCMD). During the PF uptake, the CM underwent solvent exchange and absorption in wet and dry membranes, respectively. This difference also affected the crosslinking of PCM samples via the formation of methylene bridges. Due to the PF treatment, the PCM showed lower water absorption than CM. The PF concentrations also affect the surface roughness and electrical properties of PCM samples. These findings prove that PCM can be used as a renewable and green polymer electrical insulator.

Highlights

Polymers, such as ethylene propylene rubber (EPR) [1], ethylene propylene diene methylene (EPDM) [2], silicon rubber [3], paper [4], and thermoset resins, such as phenolic resin (PF) [5], are commonly used for electrical insulation, in addition to glass and ceramic
The fabrication of phenolic cellulose membrane (PCM) materials was successfully conducted by PF impregnation of cellulose membrane (CM)
This resulted in a significant influence on the physical, chemical, thermal, and electrical properties of PCM materials

Summary

Introduction

Polymers, such as ethylene propylene rubber (EPR) [1], ethylene propylene diene methylene (EPDM) [2], silicon rubber [3], paper [4], and thermoset resins, such as phenolic resin (PF) [5], are commonly used for electrical insulation, in addition to glass and ceramic. Known as composite insulators, are suitable for use in high-voltage (HV) products because of their ability to increase the charge capacity. The advantages of this type of insulator include its light weight, low cost, superior contamination performance, high resistivity, and better flexibility, making it a suitable replacement for other materials. Cellulose is seen as a potential candidate in thermal and electrical insulation applications, due to its excellent properties that include an easy manufacturing process and high thermal stability [11]. Brzyski et al (2019) obtained cellulose with thermal conductivity ranging from 0.041 to 0.047 W/(m·K), and with a density ranging from 63 to 43 kg/m3 [14]. The addition of nanoparticles, such as silicon dioxide, titanium oxide, and montmorillonite, can mitigate current breakdown

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Conclusion