Study of Polymer Material Aging by Laser Mass Spectrometry, UV-Visible Spectroscopy, and Environmental Scanning Electron Microscopy

Junien Exposito,Frédéric Aubriet,Claude Becker,David Ruch

doi:10.1155/2007/95753

Junien Exposito, Frédéric Aubriet + Show 2 more

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https://doi.org/10.1155/2007/95753

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Abstract

Dyed natural rubber (NR) and styrene butadiene rubber (SBR), designed for outdoor applications, were exposed to an accelerated artificial aging in xenon light. The aging results in the deterioration of the exposed surface material properties. The ability of dyed polymers to withstand prolonged sunlight exposure without fading or undergoing any physical deterioration is largely determined not only by the photochemical characteristics of the absorbing dyestuff itself but also by the polymer structure and fillers. Results obtained by laser mass spectrometry, UV-visible spectroscopy, and environmental scanning electron microscopy indicate that dyed filled NR and SBR samples behave differently during the photo-oxidation. The fading of the dyed polymers was found to be promoted in the NR sample. This can be correlated with LDI-FTICRMS results, which show the absence of [M-H]− orange pigment pseudomolecular ion and also its fragment ions after aging. This is confirmed by both EDX and UV/Vis spectroscopy. EDX analysis indicates a concentration of chlorine atoms, which can be considered as a marker of orange pigment or its degradation products, only at the surface of SBR flooring after aging. Reactivity of radicals formed during flooring aging has been studied and seems to greatly affect the behavior of such organic pigments.

Highlights

Under mechanical stress, temperature, moisture, radiations, and corrosive and aggressive environments, material performances decrease over the time
After UV irradiation, the abundance of [M-H]− ion increases for styrene butadiene rubber (SBR) whereas it dramatically decreases for natural rubber (NR), which means that orange pigment is significantly destroyed at the surface of NR flooring whereas it concentrates at the surface for SBR flooring
energy dispersive X-ray spectrometry (EDX) analysis indicates a concentration of chlorine atoms, which is a marker of orange pigment or of its degradation products at the surface of SBR flooring after aging, which is not observed with NR

Summary

Introduction

Temperature, moisture, radiations, and corrosive and aggressive environments, material performances decrease over the time. The alteration of use properties is named “aging” [1]. Understanding and predicting these degradation processes are really a great challenge. The evaluation of material lifetime is very complex; this difficulty increases when composite materials are considered. Our attention is focused on a specific composite material: orange polymer-based flooring. This flooring is a mixture of different organic and inorganic fillers with an organic orange azoic pigment (C32H24N8O2Cl2) in a polymer matrix. The polymer matrix can correspond to different homopolymers or copolymers: natural rubber (NR), styrene butadiene rubber (SBR), or polybutadiene (PB)

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