Mechanical, thermal and physico-chemical behavior of virgin and hydrothermally aged polymeric pipes

Abstract

In this paper, an experimental study was conducted to characterize industrial PVC pipes and to investigate the effect of hydrothermal aging on their physico-chemical, thermal, and mechanical behavior. Three temperature (25°C, 60°C and 90°C) and full immersion in distilled water were retained as accelerated hydrothermal conditions. Kinetic of water absorption was examined and Fickian behavior was observed. The aging temperature was found to influence the water uptake behavior of PVC samples. Thermogravimetric analysis (TGA) has proved that the pipe material is not pure, while it consists of PVC reinforced with calcium carbonate (CaCO3). After exposure to accelerated aging, TGA and FTIR analysis exhibit preliminary signs of degradation of PVC samples under the retained conditions. Changes affecting the shape and the color of aged samples were examined. Mechanical properties have been characterized, after immersion of 30 days, with an improvement of strength and stiffness of the aged samples, in particular at elevated aging temperature. However, the aging response is accompanied by a loss of ductility for the aged material. These results, even for brief exposure, could help to understand the behavior of PVC composite pipes under hydrothermal conditions.

Insights into the evolution of chemical structure and pyrolysis reactivity of PVC-derived hydrochar during hydrothermal carbonization

“…3(b), the FTIR spectrum of RPVC showed bands at 713 cm −1 and 875 cm −1 that were attributed to the in-plane and out-of-plane stretching vibrations of CO 3 2− . 62 A composite absorption band centered at 1425 cm −1 was ascribed to the vibrations of –CH 2 in the PVC, COO in the stabilizer, and the CO 3 2− in CaCO 3 . 62,63 The higher intensity of the CO 3 2− peak clearly indicated that RPVC contained a considerable proportion of CaCO 3 filler.…”

“…62 A composite absorption band centered at 1425 cm −1 was ascribed to the vibrations of –CH 2 in the PVC, COO in the stabilizer, and the CO 3 2− in CaCO 3 . 62,63 The higher intensity of the CO 3 2− peak clearly indicated that RPVC contained a considerable proportion of CaCO 3 filler. The peaks located at 617 cm −1 , 1250 cm −1 , 2817 cm −1 , and 2962 cm −1 gradually weakened with increasing HTC temperature.…”

Decomposition of Irganox 1010 in plastic bonded explosives

“…Polymeric materials have a wide array of applications ranging from solar‐thermal systems, piping for water, automotive parts, food packing, and explosives 1–5 . For each application, the physical and chemical properties of the polymer must be preserved in order for the polymer to function as intended.…”

“…Polymeric materials have a wide array of applications ranging from solar-thermal systems, piping for water, automotive parts, food packing, and explosives. [1][2][3][4][5] For each application, the physical and chemical properties of the polymer must be preserved in order for the polymer to function as intended. For polymer bonded explosives (PBXs), this is especially critical because the polymers reduce the sensitivity of the explosives, impart mechanical strength to pressed parts, and improve the overall manufacturability.…”

Influence of hygrothermal ageing on the novel infusible thermoplastic resin reinforced with quadriaxial non-crimp glass fabrics

“…However, water absorption is inevitable as its presence may cause swelling, plasticization and debonding of fibres from the matrix, thereby shortening the service life composites. 17,[20][21][22][23][24][25] Few researchers have reported the effect of mechanical properties degradation on GF reinforced Elium ® composites due to water absorption. 11,16,26 Davies et al 11 studied the influence of seawater ageing on the mechanical behaviour of acrylic matrix and GF composites.…”