The effects of weathering exposure on the physical, mechanical, and thermal properties of high-density polyethylene and poly (vinyl chloride)

Abstract

This paper presents results describing the physical, mechanical, and thermal properties (melt flow index -MFI and oxidative induction time -OIT) of high density polyethylene and poly (vinyl chloride) after weathering exposure (6, 12, 18, and 30 months). The materials exposed were geomembranes of two thicknesses: 1.0 and 2.0 mm (PVC) and 0.8 and 2.5 mm (HDPE). The climate parameters (average) obtained were 25 °C (temperature), 93 mm (precipitation), 66% (relative humidity), and 19 MJ/m 2 .day (intensity of global radiation). Some results showed, for instance, that the behavior of the geomembranes changed after the exposures. A few minor variations in physical properties occurred. The density and thickness, for instance, varied 0.5-1.0% (average) for both the PVC and HDPE geomembranes. The mechanical properties changed as a function of the period of exposure. In general, some decreases were verified by the deformation of PVC. The samples became more rigid. In contrast, HDPE geomembranes became more ductile. Despite the variations in elasticity, some increases in deformability were verified. An MFI test showed some degradation in HDPE geomembranes. OIT tests revealed small values for both intact and exposed samples.

Potential use of waste from tree pruning and recovered plastic to obtain a building material: Case study of Merida, Mexico

“…The mechanical performance of the sheets, when subjecting them to the two types of load described, can be explained by the different mechanical resistance of the main raw materials with which each type of sheet is manufactured, and by the effect of weathering on the properties of each type of material. This has been reported in several works and in the references cited therein, for instance Berdahl et al (2008), Ibach et al (2007), Kazemi Najafi (2013), Lodi et al (2013), Naldony et al (2016), Pendleton et al (2002), Ramírez-Chan et al (2014) and Wypych (2018).…”

Laboratory Study of the Ultraviolet Radiation Effect on an HDPE Geomembrane

“…The present work analyzed an HDPE smooth geomembrane with 1.0 mm of nominal thickness manufactured in Brazil. The material was produced by the extrusion-blown film process and formulated with 96-97.5% of medium-density polyethylene (density ≥ 0.940 g cm −3 ), 2-3% of carbon black and 0.5-1.0% of antioxidants and thermostabilizers [20]. The geomembrane's roll has dimensions of 5.90 m of width and 100 m of length.…”

Avaliação da inflamabilidade e do envelhecimento natural de compósitos de polímero verde e argila vermiculita para potencial uso na construção civil

“…A tendência de aumentar o uso dos plásticos em aplicações externas, como na construção civil, tem resultado no desenvolvimento de pesquisas para a concepção de materiais com a requerida estabilidade em suas propriedades quando expostos à degradação abiótica (RATANAWILAI;TANEERAT, 2018;ANDRADY et al, 1998). A maioria dos polímeros utilizados para essa finalidade têm aditivos foto-estabilizantes e antioxidante para controlar o envelhecimento e assegurar um tempo de vida útil aceitável (LODI;BUENO;VILAR, 2013;ANDRADY et al, 1998).…”