The effect of ultraviolet irradiation and temperature on the resilience of high density polyethylene

2014 ◽  
Vol 34 (8) ◽  
pp. 727-731
Author(s):  
Naouri Ladaci ◽  
Ahmed Belbah ◽  
Kheirddine Kraim ◽  
Nadia Mebarki
Keyword(s):  
Public Health ◽  
Climate Change ◽  
High Density Polyethylene ◽  
Aging Process ◽  
Irradiation Time ◽  
Accelerated Aging ◽  
High Density ◽  
External Shocks ◽  
Two Factors ◽  
Different Temperatures

Abstract High density polyethylene (HDPE) has recently been established as the material of choice for the distribution and transport of drinking water on economic and public health levels. Because of this, a simulation study was conducted to investigate the effect of aging by two factors on HDPE, in order to check the mechanical robustness of this material with regards to climate change. First, specimens of the material (HDPE80) underwent treatment with irradiation by ultraviolet (UV) radiation for different periods up to 120 h. The accelerated aging process by UV irradiation gave a negative correlation between resilience and the irradiation time in hours. Second, we tested the HDPE80 resilience to different temperatures, at various notch depths (0.4, 0.8, 1, 1.25 and 1.5 mm), to external shocks.

scholarly journals MECHANICAL CHARACTERIZATION OF PA 12 AND HDPE PIPES BEFORE AND AFTER AGING IN WATER AT TWO DIFFERENT TEMPERATURES

2021 ◽  
Vol 9 (1) ◽  
pp. 248-256
Author(s):  
J.A. dos Santos ◽  
R.C. Tucunduva ◽  
J.R.M. D’Almeida
Keyword(s):  
High Density Polyethylene ◽  
Mechanical Performance ◽  
High Density ◽  
Effect Of Temperature ◽  
Polyamide 12 ◽  
Polyethylene Pipes ◽  
Before And After ◽  
Different Temperatures ◽  
Deterioration Process ◽  
Combined Action

Polymer pipes are being widely used by many industrial segments. Although not affected by corrosion, the mechanical performance of these pipes can be reduced due to exposure to temperature, UV radiation and by contact with various fluids. Depending on the deterioration process, embrittlement or plasticization may occur, and the service life of the pipe can be severely reduced. In this work, the combined action of temperature and water upon the mechanical performance of polyamide 12 and high-density polyethylene pipes is evaluated. Destructive and non-destructive techniques were used and the performance of both materials was compared. Both polymers were platicized by the effect of water. However, for high density polyethylene the effect of temperature was more relevant than for polyamide. This behavior was attributed to the dependence of the free volume with the markedly different glass transition temperature of the polymers and the temperatures of testing.

scholarly journals Rheological and Thermal Behavior of High-Density Polyethylene (HDPE) at Different Temperatures

2014 ◽  
Vol 05 (13) ◽  
pp. 923-931 ◽  
Author(s):  
Cynthia D’Avila Carvalho Erbetta ◽  
Getúlio F. Manoel ◽  
Ana Paula Lelis Rodrigues Oliveira ◽  
Maria Elisa Scarpelli Ribeiro e Silva ◽  
Roberto Fernando Souza Freitas ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
High Density Polyethylene ◽  
High Density ◽  
Different Temperatures

Accelerated Aging Cycle of Composite Reinforced High Density Polyethylene (HDPE) Roofing Panel

2015 ◽  
Vol 799-800 ◽  
pp. 192-195
Author(s):  
Mansur Ahmad ◽  
Nurul Atiqah Mohd Ayob ◽  
Nurul Nadia Mohd Khairuddin
Keyword(s):  
Water Vapor ◽  
Elevated Temperature ◽  
Water Absorption ◽  
High Density Polyethylene ◽  
Accelerated Aging ◽  
High Density

The purpose of this study is to investigate the effect of accelerated aging cycle (AAC) on water absorption of the composites. The HDPE composite was subjected to a series of six ageing cycles at an elevated temperature. The cycle consist of immersion in water at (49 ± 2°C), explosion to steam and water vapor (93 ± 2°C), stored in freezer (-12 ± 2°C), and heated in oven (99 ± 2°C). It took approximately twelve days to complete this aging cycle. The effect and the changes of water absorption for both control and after accelerated aging were observed and determined. The results showed that water absorption was significant as the greater the fibre percentage, the higher the water absorption. This behavior occurs for both conditions. There were significant differences in the percentage of the water absorption for both control and accelerated aging cycle.

scholarly journals Recolhimento de embalagens vazias de agrotóxicos no Rio Grande do Norte de 2006 a 2014

2015 ◽  
Vol 10 (2) ◽  
pp. 01
Author(s):  
A. S. P. Sousa ◽  
R. Sales Júnior ◽  
A. M. P. Negreiros ◽  
T. S. Oliveira
Keyword(s):  
Public Health ◽  
Agricultural Production ◽  
High Density Polyethylene ◽  
Rio Grande ◽  
Biological Agents ◽  
High Density ◽  
Empty Containers

<p>Os agrotóxicos são substâncias utilizadas para o controle de agentes biológicos não desejáveis a produção agrícola, e o descarte inadequado de suas embalagens podem contaminar o meio ambiente e ainda colocar em risco a saúde pública. Sendo assim, este trabalho tem por objetivo quantificar o volume de tipos de embalagens que foram processadas e encaminhadas para incineração e reciclagem pela Central de Recebimento de Embalagens Vazias de Agrotóxicos de Mossoró – RN nos anos de 2006 a 2014. Neste período deram entrada na central um total de 488.76 t de embalagens vazias de agrotóxicos e até o final de 2014, 450.53 t desse material foram processados e transportados para recicladoras ou incineradoras, totalizando aproximadamente 92% das embalagens recebidas pela Central. As embalagens de Polietileno de Alta Densidade e papelão foram as que representaram o maior percentual de processamento e retirada da Central 40,36 e 28,10%, respectivamente.  Em contrapartida, os menores valores percentuais de retirada foram para o aço e as tampas das embalagens 2,16 e 4,03%, respectivamente. As embalagens contaminadas ou não laváveis representaram 11,44% do valor total processado.</p><p align="center"><strong><em>Collecting empty containers of pesticides in Rio Grande do Norte 2006-2014</em></strong></p><p><strong>Abstract</strong><strong>: </strong>Pesticides are substances used to control unwanted biological agents agricultural production, and improper disposal of its packaging can contaminate the environment, and endanger public health. Thus, this study aims to quantify the volume of packaging types that have been processed and sent for incineration and recycling by Empties Receiving Center of Pesticide Mossoro - RN in the years 2006 to 2014. In this period were received at central a total of 488.76 tons of empty pesticide containers and by the end of 2014, 450.53 t of this material were processed and transported to recycling or incineration, totaling approximately 92% of packages received by the Central. Packaging of High Density Polyethylene and cardboard were those that represented the highest percentage of processing and withdrawal of Central 40.36 and 28.10%, respectively. In contrast, smaller percentages were taken from the steel and to the lids of containers 2.16 and 4.03%, respectively. Contaminated or not cleanable packaging accounted for 11.44% of the total amount processed.</p>

A Study on Small Punch Test to Characterize Mechanical Property of Aged High-Density Polyethylene (HDPE)

2017 ◽  
Vol 734 ◽  
pp. 104-115 ◽  
Author(s):  
Bo Zhao ◽  
Jing Guo ◽  
Yu Xin Yu ◽  
Xue Tao Zhang ◽  
Tong Xu ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Irradiation Time ◽  
Hardness Test ◽  
Maximum Load ◽  
Tensile Tests ◽  
High Density ◽  
Tensile Fracture ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test

In this work, accelerated ultraviolet (UV) aging of high density polyethylene (HDPE) was prepared, and tensile tests, Shore D hardness test and small punch test (SPT) were carried out. The macroscopical morphology of tensile fracture and microscopical morphology of SPT have been observed successively. The result showed that HDPE aging significantly increased with the UV irradiation time, because of amount of microfiber dropping, the entanglement of molecular segments on the non-crystalline decreasing, and the difficulty degree of craze microfiber fracture reducing.After aging for over 504 hours, aged layer can be observed on specimens’ surface, meanwhile, polymer brittleness increased, tensile strength had no significant change, elongation at break declined 29.53%, and Shore hardness value increased 6.9%. SPT performed more susceptibly on aged HDPE, and the maximum load dropped more than 39%. This illustrated that SPT is more suitable for the assessment to aged HDPE, which could more focus on aged layer.

Composition and Surface Topography Effects on Apatite-Forming Ability of Ceramic-Polymer Composites

2003 ◽  
Vol 774 ◽  
Author(s):  
Susan M. Rea ◽  
Serena M. Best ◽  
William Bonfield
Keyword(s):  
Surface Topography ◽  
High Density Polyethylene ◽  
High Density ◽  
Apatite Layer ◽  
Biologically Active ◽  
Human Blood Plasma ◽  
Apatite Formation ◽  
Polyethylene Matrix ◽  
Composite Surface ◽  
X Ray

AbstractHAPEXTM (40 vol% hydroxyapatite in a high-density polyethylene matrix) and AWPEX (40 vol% apatite-wollastonite glass ceramic in a high density polyethylene matrix) are composites designed to provide bioactivity and to match the mechanical properties of human cortical bone. HAPEXTM has had clinical success in middle ear and orbital implants, and there is great potential for further orthopaedic applications of these materials. However, more detailed in vitro investigations must be performed to better understand the biological interactions of the composites and so the bioactivity of each material was assessed in this study. Specifically, the effects of controlled surface topography and ceramic filler composition on apatite layer formation in acellular simulated body fluid (SBF) with ion concentration similar to those of human blood plasma were examined. Samples were prepared as 1 cm × 1 cm × 1 mm tiles with polished, roughened, or parallel-grooved surface finishes, and were incubated in 20 ml of SBF at 36.5 °C for 1, 3, 7, or 14 days. The formation of a biologically active apatite layer on the composite surface after immersion was demonstrated by thin-film x-ray diffraction (TF-XRD), environmental scanning electron microscopy (ESEM) imaging and energy dispersive x-ray (EDX) analysis. Variations in sample weight and solution pH over the period of incubation were also recorded. Significant differences were found between the two materials tested, with greater bioactivity in AWPEX than HAPEXTM overall. Results also indicate that within each material the surface topography is highly important, with rougher samples correlated to earlier apatite formation.

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