Thermo-gravimetric Analysis (TGA) after Different Exposures of High Density Polyethylene (HDPE) and Poly Vinyl Chloride (PVC) Geomembranes

 

Paulo César Lodi

Associate Professor, PhD; Department of Civil Engineering, UNESP – São Paulo State University, Av. Eng. Luiz Edmundo C. Coube 14-01, 17.033-360, Bauru (SP), Brazil; e-mail: plodi@feb.unesp.br

Benedito de Souza Bueno

Professor, PhD; Department of Geotechnical Engineering, São Carlos School of Engineering, University of São Paulo (USP), Avenida do Trabalhador Sancarlense 400, 13.566-590, São Carlos (SP), Brazil;
e-mail: bsbueno@sc.usp.br

 

 ABSTRACT

This paper presents the results of thermogravimetric analysis (TGA) tests in PVC (1.0; 2.0 mm) and HDPE (0.8; 2.5 mm) geomembranes exposed to weathering and leachate after 30 months. The aim of this paper is the comparison of fresh and exposed samples to assess the degradation process concerning the total loss of mass of geomembranes. The exposure was conducted in accordance with the recommendations of ASTM standards. The TGA tests were carried out according to ASTM D6370 and E2105. Results show, for instance, that for PVC geomembrane the largest reductions of plasticizers occurred for samples exposed to weathering. The loss of plasticizers after the exposure contributed to the decrease of deformation and consequent increase in stiffness. TGA tests shows to be a valuable tool to control the quality of the materials.

Keywords: PVC and HDPE Geomembranes, Chemical degradation, Weathering, TGA tests.

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