UV laser induced fluorescence in high-density polyethylene

Abstract

Multi-component fluorescence was induced from 'pure-density polyethylene using two different ultraviolet sources and detected by two different systems. Fluorescence from the wavelength region around 358 nm was attributed to monomeric emission from the chromophores introduced as unavoidable oxidation products such as carbonyl compounds during the processing of the 'as received' samples. The second major emission peak, red shifted by 50 nm, is attributed to excimer decay. A slow component of decay ( tau =50 ns) appearing at longer wavelengths supports a kinetic scheme for excimeric decay. The monomeric decay time spectrum was obtained and presented as an alternative means of characterisation of the materials.