Broadband Far-infrared Spectroscopic Identification and Quantification of Antioxidants in Polymeric Insulation

Broadband far-infrared absorption spectra were measured for sheets of low density polyethylene (LDPE), containing various contents of three kinds of phenol-type antioxidants, BHT, Irganox 1010, and Irganox 1330. Each antioxidant exhibits its characteristic spectrum with various peaks, most of which show a monotonic increase in intensity with the increase in content of antioxidant. Therefore, we can identify and quantify the antioxidants added in LDPE.

I. Introduction

Organic polymers are used as electrical insulating materials in many industrial fields. However, if they are processed at high temperatures or they are used for a long time under a harsh environment, oxidative degradation occurs. Such degradation may cause a serious accident or malfunction to electrical apparatus. Therefore, antioxidants are usually added to polymeric insulating materials.