Table of Contents
Journal of Polymers
Volume 2015 (2015), Article ID 286187, 8 pages
http://dx.doi.org/10.1155/2015/286187
Research Article

Study of Antioxidant Effectiveness of Kraft Lignin in HDPE

1Laboratory of Chemical Analysis and Electrochemistry, Department of Chemistry, Faculty of Engineering, University of Zulia, Maracaibo 4001, Venezuela
2Laboratory of Analytical Instruments, Department of Chemistry, Faculty of Sciences, University of Zulia, Maracaibo 4001, Venezuela

Received 15 May 2015; Revised 4 July 2015; Accepted 5 July 2015

Academic Editor: Yves Grohens

Copyright © 2015 I. Piña et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Polymers are subject to oxidative degradation during all steps of their useful cycle. This degradative process is prevented using stabilizers like antioxidant of the type sterically hindered phenols or amines. Lignin, due to the presence of phenolic groups in their structure, can present characteristic as antioxidant agent, in a similar way to the additives used in polymers. Therefore, in this work, the antioxidant capacity of the lignin in a sample of polyethylene is studied. For this reason, in this paper, a method based on nonisothermal differential scanning calorimetry (DSC) to evaluate this property is used. The samples studied were subjected to heat treatment at different scan rates and in presence of oxygen to promote thermooxidation of the material. The antioxidant capacity of different formulations of lignin and additives in the polymer resin was determined from the temperature of onset of oxidation () at different heating rates and adjusting Arrhenius model prediction. The results indicate that the procedure can predict the antioxidant capacity of antioxidant additives in HDPE with good reproducibility and accuracy, according to the Arrhenius model prediction.