Studies on Mechanical and Chemical Property Changes of Environmental Degradation Polyethylene Mulching Film Immersed in Water Environment

2013 ◽  
Vol 726-731 ◽  
pp. 580-583
Author(s):  
Bin Bin Zhao ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Hong Ping Zhang
Keyword(s):  
Absorption Band ◽  
Environmental Degradation ◽  
Mechanical Characteristics ◽  
Morphological Changes ◽  
Water Environment ◽  
Elongation At Break ◽  
Polyethylene Mulching ◽  
Hydroxyl Absorption ◽  
Property Changes ◽  
Mulching Film

This research studied the effects of the water environment on the mechanical, chemical and morphological changes of environmental degradation polyethylene mulching film. The mechanical characteristics of the environmental degradation polyethylene mulching film immersed in water environment or exposed in air declined. The elongation at break retention of the sample immersed in water reached minimum value for 70 days while 40 days for sample exposed in air. FTIR showed new hydroxyl absorption band appeared at 1717cm-1after exposed for 60 days. The relative intensity of absorption band of sample exposed in air is higher than sample immersed in water. AFM images showed large fluctuation on the surface after immersed in water or exposed in air for 60days.

Studies on the Property Changes of Environmental Degradation Mulching Film and Polyethylene Mulching Film in Water Environment

2012 ◽  
Vol 268-270 ◽  
pp. 241-244
Author(s):  
Bin Bin Zhao ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Hong Ping Zhang
Keyword(s):  
Environmental Degradation ◽  
Water Environment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polyethylene Mulching ◽  
Before And After ◽  
Diffraction Peaks ◽  
Property Changes ◽  
Mulching Film

This paper studied the property changes of environmental degradation mulching film and polyethylene mulching film in water environment. The XRD (X-ray diffraction) cures showed that the diffraction angles of environmental degradation mulching film were not changed but intensities and area of diffraction peaks increased after immersion for 60 days; while the diffraction angles and area of diffraction peaks of polyethylene mulching film were same before and after immersion. Cracks and holes appeared in surface of environmental degradation mulching film, but it was still smooth and uniform for the polyethylene mulching film after immersion.

scholarly journals Technical Evaluation Method for Physical Property Changes due to Environmental Degradation of Grout-Injection Repair Materials for Water-Leakage Cracks

2019 ◽  
Vol 9 (9) ◽  
pp. 1740 ◽  
Author(s):  
Jiang ◽  
Oh ◽  
Kim ◽  
He ◽  
Oh
Keyword(s):  
Environmental Degradation ◽  
Evaluation Method ◽  
Physical Property ◽  
Performance Comparison ◽  
Test Method ◽  
Grout Injection ◽  
Chemical Corrosion ◽  
Technical Evaluation ◽  
Injection Materials ◽  
Property Changes

Leakage in below-grade concrete structures are repaired using various types of grout-injection materials, but the selection of optimal material types with a consideration of the environmental degradation factors are not conducted. Different degradation factors can act on the waterproofing membranes or grout-injection materials simultaneously. Especially in the early stages of installation, the injected grout materials in the cracks for leakage repair or for reforming damaged waterproofing layers are subject to complex forms of degradation factors. In such cases, physical property changes to the materials can reduce the waterproofing performance of the grout-injection materials. In this study, a technical evaluation regime is proposed for selecting the optimal repair material to be used in underground concrete structure leakage cracks. In this study, six environmental degradation factors (thermal stress, chemical corrosion, erosion due to ground water flow, hydrostatic pressure, substrate movement, and humidity on concrete surface) are identified. Corresponding evaluation methods based on the ISO TS 16774 test method series were used for each factor to assess the performance evaluation of four different types of grout-injection materials (acrylic resin, epoxy resin, polyurethane foam, and synthetic polymerized rubber gel). Based on the test results, a new comprehensive evaluation regime is presented that allows a quantitative performance comparison between each type of grout-injection material.

scholarly journals Evaluation of Microcrystalline Chitosan and Fibrin Membranes as Platelet-Derived Growth Factor-BB Carriers with Amoxicillin

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Kazimiera H. Bodek ◽  
Karolina M. Nowak ◽  
Marcin Kozakiewicz ◽  
Andrzej Bodek ◽  
Marta Michalska
Keyword(s):  
Growth Factor ◽  
Mechanical Characteristics ◽  
Composite Membranes ◽  
Mechanical Tests ◽  
Platelet Derived Growth Factor ◽  
Sem Images ◽  
Elongation At Break ◽  
Microcrystalline Chitosan ◽  
Kinetics Of

The aim of this study was to describe the mechanical and sorption features of homogeneous and composite membranes which consist of microcrystalline chitosan (MCCh) and fibrin (Fb) in various proportions as well as thein vitrokinetics of platelet-derived growth factor-BB (PDGF-BB) released from ten types of membranes in the presence or absence of amoxicillin (Am). The films were characterized by Fourier transform infrared (FTIR) spectroscopy, mechanical tests: breaking strength (Bs) and elongation at break (Eb), as well as SEM images, and swelling study. The influence of the form of samples (dry or wet) on Young’s modulus (E) was also examined. The homogeneous MCCh (M1) and composite M3 and M4 (MCCh : Fb = 2 : 1 and 1 : 1) membranes were characterized by good sorption properties and higher mechanical strength, when compared with Fb (M2) membrane. Connecting MCCh with Fb decreases release of PDGF-BB and increases release of Am. The most efficient release of PDGF-BB was observed in the case of M4 (the optimum MCCh : Fb ratio was 1 : 1) membrane. It was found that the degree of PDGF-BB release from the membrane is influenced by the physicochemical and mechanical characteristics of the films and by its affinity to growth factor PDGF-BB.

scholarly journals A Facile Method to Fabricate Anisotropic Extracellular Matrix with 3D Printing Topological Microfibers

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3944 ◽  
Author(s):  
Zhen Gu ◽  
Zili Gao ◽  
Wenli Liu ◽  
Yongqiang Wen ◽  
Qi Gu
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Mechanical Characteristics ◽  
Fiber Direction ◽  
Gelatin Matrix ◽  
Simple Method ◽  
Elongation At Break ◽  
Anisotropic Mechanical Properties ◽  
The Matrix ◽  
3D Printed

Natural tissues and organs have different requirements regarding the mechanical characteristics of response. It is still a challenge to achieve biomaterials with anisotropic mechanical properties using an extracellular matrix with biological activity. We have improved the ductility and modulus of the gelatin matrix using 3D printed gelatin microfibers with different concentrations and topologies and, at the same, time achieved anisotropic mechanical properties. We successfully printed flat microfibers using partially cross-linked gelatin. We modified the 10% (w/v) gelatin matrix with microfibers consisting of a gelatin concentration of 14% (w/v), increasing the modulus to about three times and the elongation at break by 39% in parallel with the fiber direction. At the same time, it is found that the microfiber topology can effectively change the matrix ductility, and changing the modulus of the gelatin used in the microfiber can effectively change the matrix modulus. These findings provide a simple method for obtaining active biological materials that are closer to a physiological environment.

A Simple Model for Predicting Heat Aging of EPDM Rubber

2004 ◽  
Vol 77 (2) ◽  
pp. 242-256 ◽  
Author(s):  
Arnis U. Paeglis
Keyword(s):  
Physical Properties ◽  
Strain Energy ◽  
Physical Property ◽  
Elongation At Break ◽  
Epdm Rubber ◽  
Wide Range ◽  
Rate Relationship ◽  
Property Changes ◽  
Simple Empirical Model

Abstract Heat aging stability is a hallmark of EPDM rubber and a requirement for use in automotive, roofing and other applications. Retention of physical properties after accelerated heat aging is a typical specification for such long-term uses. This paper examines the utility of such tests in predicting results over a range of temperatures, 116 °C, 125 °C, 135 °C and 150 °C, in some cases for as long as 365 days. A simple empirical model was developed to predict the retention of physical properties using fractional strain energy, that is, the ratio of the aged to unaged products of tensile strength and elongation at break. Characteristic rates, an Arrhenius rate relationship and activation energies were determined. This model provides a basis to predict physical property changes over a wide range of temperatures and times, as well as for considerations of equivalent heat aging tests and use in different applications.

Quality Analysis of Welded and Soldered Joints of Cu-Nb Microcomposite Wires

1970 ◽  
Vol 17 (1) ◽  
pp. 16-19 ◽  
Author(s):  
Nikolaj VIŠNIAKOV ◽  
Jurij NOVICKIJ ◽  
Danutė ŠČEKATUROVIENĖ ◽  
Adomas PETRAUSKAS
Keyword(s):  
Tensile Stress ◽  
Mechanical Characteristics ◽  
Testing Machine ◽  
Optical Microscope ◽  
Butt Joint ◽  
Ultimate Tensile Stress ◽  
Quality Analysis ◽  
Elongation At Break ◽  
Stress Limit ◽  
Steel Sleeve

Quality analysis of welded and soldered joints of Cu-Nb microcomposite wires has been performed. Quality and mechanical characteristics of joints as ultimate tensile stress limit and elongation at break were measured with an universal testing machine and controlled visually using an optical microscope. Two wires joints were soldered with silver and copper solders and put into steel and copper sleeve respectively. Another two wires joints were soldered with silver solder and welded without any reinforcement. Joints soldered with the silver solder and steel sleeve have demonstrated the best mechanical characteristics: ultimate tensile stress limit of 650 MPa and elongation at break of 0.85 %. Joints soldered with the copper sleeve have no advantages comparing with the soldered butt joint. Ultimate tensile stress limit and elongation at break were in 300 MPa - 350 MPa and in 0.35 % - 0.45 % ranges respectively. Two welded joints had ultimate tensile stress limit of 470 MPa and elongation at break of 0.71 %. In all joints the microstructure of Nb filaments was destroyed and mechanical properties have been specified by mechanical strength of copper and sleeve materials only.http://dx.doi.org/10.5755/j01.ms.17.1.242

scholarly journals Effects of Different Plastic Mulching Film on Soil Hydrothermal Status and Water Utilization by Spring Maize in Northwest China

2021 ◽  
Vol 8 ◽  
Author(s):  
Ruhua Liu ◽  
Zhenhua Wang ◽  
Hanchun Ye ◽  
Wenhao Li ◽  
Rui Zong ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Use Efficiency ◽  
Water Use ◽  
Drip Irrigation ◽  
Biodegradable Film ◽  
Polyethylene Mulching ◽  
Film Treatment ◽  
Use Efficiency ◽  
Mulching Film ◽  
Mulching Films

The problem of residual film pollution in farmland caused by polyethylene mulching films is serious. The application effects of different mulching films combined with drip irrigation on maize planting in the Ili area, Xinjiang, China, were explored. In this study, four types of mulching films and non-mulching treatment were used to study the degradation properties of different plastic mulching and their effects on the dynamic changes of soil moisture, heat, and crop yields of maize under drip irrigation. The results showed that after 160 days of mulching film, only small cracks appeared in polyethylene mulching films. The degradation performance of white oxo-biodegradable film treatment was optimal than the black oxo-biodegradable film treatment. The quality loss rate of the two biodegradable films were 52.26 and 48.48%, respectively. Various mulching film treatments could increase soil moisture in the early stage of maize growth. At the 0–60 cm soil layer, the soil moisture under the white oxo-biodegradable mulching film and black oxo-biodegradable mulching film treatments were lower by 2.75 and 2.66% (p < 0.05) than the white polyethylene mulching film and black polyethylene mulching film treatments. The soil water consumption was highest in the non-mulching treatment, followed by biodegradable film, and the small least value was observed in the polyethylene film treatment. The average soil temperature at depth of 0–15 cm in white polyethylene mulching film, black polyethylene mulching film, white oxo-biodegradable mulching film, and black oxo-biodegradable mulching film treatments were 1.43, 1.16, 0.72 and 0.64°C higher than the non-mulching treatment, respectively. Mulching films treatment played a critical role in increasing production and improving water use efficiency. The black polyethylene mulching film treatment had the highest yield and the best water use efficiency. The black oxo-biodegradable mulching film treatment only reduces the yield by 0.33% compared to the black polyethylene mulching film treatment, and the water use efficiency was only reduced by 0.90% (p > 0.05). Comprehensive analysis showed that black oxo-biodegradable mulching film could be used as a substitute for polyethylene mulching film and can be applied to the production practice of drip irrigation maize in the Ili area.

scholarly journals Modification of nitrile butadiene rubber at the stage of its allocation

2018 ◽  
Vol 80 (3) ◽  
pp. 323-329
Author(s):  
V. A. Sedykh ◽  
O. V. Karmanova ◽  
E. V. Koroleva
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Butadiene Rubber ◽  
Rubber Latex ◽  
Retention Capacity ◽  
Elongation At Break ◽  
Dry Mixing ◽  
Selection Of

Search for additives that increase the wear resistance of rubbers is relevant. It is known that the introduction of hollow corundum microspheres (NCM) into rubber reduces the wear of rubber products. The uniform distribution of small amounts of microspheres in rubber by traditional "dry" mixing in a rubber mixer or on rollers is difficult. Microspheres were introduced into rubber at the stage of its separation from latex. The work consisted in the selection of thickeners capable of holding the NSM in rubber latex SCN-18SNT at the stage of its coagulation, and evaluation of physical and mechanical properties of rubbers in the presence of NCM. The retention capacity of thickeners of polyacrylamide (PAA), carboxymethylcellulose (CMC) and polyvinyl alcohol (PVA) was determined. Thickened latex was coagulated in the presence of microspheres with polymeric coagulant and sulfuric acid. When filling the polymer with microspheres, it is preferable to use a PAA thickener. The yield of microspheres in rubber using thickeners PAA, CMC and PVA was 71.1, 66.5 and 38.7% , respectively. The physico-mechanical characteristics of rubbers based on SKN-18SNT in the presence of microspheres introduced both as a "dry" method in rubber and at the stage of its isolation from latex are determined. The presence of microspheres in an amount of 4.4-4.7% by weight. on rubber, did not affect the hardness and elasticity of rebound rubbers. It has been confirmed that the presence of microspheres, especially those introduced from the latex rubber release stage, provides an increase in abrasion resistance. In turn, the presence of microspheres in rubber with traces of polyacrylamide provided an increase in the resistance of rubbers to tearing, the modulus at 100 and 200% elongation with a decrease in the elongation at break.

Experimental and estimated determination of mechanical characteristics of 3D printed ABS plastic samples under tension

2021 ◽  
Author(s):  
A.V. Shmelev ◽  
V.I. Ivchenko ◽  
A.V. Talaluev
Keyword(s):  
Mechanical Characteristics ◽  
Test Results ◽  
Bilinear Model ◽  
Elongation At Break ◽  
Computational Estimation ◽  
Loading Mode ◽  
3D Printed ◽  
Break Yield ◽  
Raster Pattern

The paper introduces the results of an experimental study of the mechanical characteristics of 3D printed ABS plastic ABSplus-P430 samples under tension. These 3D printed samples differ in the orientation of the material layers, formed by the position of the samples when printed, and the print raster pattern. During the tests, the material showed isotropic properties in terms of Young’s modulus and anisotropic properties for elongation at break, yield strength, and ultimate strength. We revealed that the print orientation relative to the direction of the applied load significantly affects the strength of the tested samples. Using the obtained test results, the specified parameters of the bilinear model of the material were identified by performing a series of computational studies using computer finite element models of material samples. The found parameters of the bilinear model of the material can be used to carry out computational estimation of the strength and bearing capacity of ABS plastic products manufactured by 3D printing. The results obtained also make it possible to develop recommendations for the orientation of products in the printing area according to the criterion of ensuring the greatest strength, taking into account the loading mode of the product.

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