scholarly journals Recycling of Mineral Water Bottles with Chemical Foaming

2017 ◽  
Vol 10 (2) ◽  
pp. 157 ◽  
Author(s):  
V. A. Szabó ◽  
G. Dogossy

Today, in the field of packaging technologies there is an increasing amount of one-way polymer materials. Such materials after their short lifecycle are disposed, and such pose a serious environmental impact. However, PET is a good quality technical plastic; the recycled use must be provided. In our research, we have examined the recycled material of mineral water bottles. Chemical foaming of recycled polyethylene terephthalate (rPET) was applied for quality increased reusability. Significant results were achieved in terms of mechanical properties at specific mixtures of chain extender and impact resistance enhancer, at the foaming state of the injection moulding.

2021 ◽  
Vol 23 (3) ◽  
pp. 1152-1176
Author(s):  
H. Okubo ◽  
S. Yao

AbstractTo develop material-recycling processes for used plastic products, it is necessary to design new material-recycling techniques to optimize the mechanical properties of the recycled plastics since the mechanical properties of recycled plastic products are normally deteriorated. In this study, we suggest one of the approaches that is a repelletizing treatment for improving the mechanical properties of recycled-polyethylene moldings using a twin-screw extruder. The results of the tensile test revealed the significant effect of the repelletizing treatment on the tensile performance of the recycled-polyethylene moldings. The tensile performance of the repelletized recycled-polyethylene moldings was significantly higher than that of the original recycled-polyethylene moldings under specific repelletizing conditions. The analysis of the polymeric structures revealed the significant effect of the repelletizing treatment on the secondary and higher-order structures such as the lamellar shape, aggregation of the crystal domains, amorphousness, and polyethylene chain conformation in the recycled-polyethylene moldings. The repelletizing treatment increased the tensile performances by optimizing the internal structure of the recycled-polyethylene moldings. The results confirmed the efficacy of the repelletizing treatment to optimize the mechanical performance of the recycled-polymer materials, thereby facilitating the reuse of waste plastics as value-added materials for various industrial applications.


2013 ◽  
Vol 773-774 ◽  
pp. 488-495 ◽  
Author(s):  
Dennis V. de Pellegrin

This work is motivated by the need to efficiently machine the edges of ophthalmic polymer lenses for mounting in spectacle or instrument frames. The polymer materials used are required to have suitable optical characteristics such high refractive index and Abbe number, combined with low density and high scratch and impact resistance. Edge surface finish is an important aesthetic consideration; its quality is governed by the material removal operation and the physical properties of the material being processed. The wear behaviour of polymer materials is not as straightforward as for other materials due to their molecular and structural complexity, not to mention their time-dependent properties. Four commercial ophthalmic polymers have been studied in this work using nanoindentation techniques which are evaluated as tools for probing surface mechanical properties in order to better understand the grinding response of polymer materials.


2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


2020 ◽  
Vol 67 (2) ◽  
pp. 115-120
Author(s):  
Raisa A. Alekhina ◽  
Victoriya E. Slavkina ◽  
Yuliya A. Lopatina

The article presents options for recycling polymers. The use of biodegradable materials is promising. This is a special class of polymers that can decompose under aerobic or anaerobic conditions under the action of microorganisms or enzymes forming natural products such as carbon dioxide, nitrogen, water, biomass, and inorganic salts. (Research purpose) The research purpose is in reviewing biodegradable materials that can be used for the manufacture of products used in agriculture. (Materials and methods) The study are based on open information sources containing information about biodegradable materials. Research methods are collecting, studying and comparative analysis of information. (Results and discussion) The article presents the advantages and disadvantages of biodegradable materials, mechanical properties of the main groups of biodegradable polymers. The article provides a summary list of agricultural products that can be made from biodegradable polymer materials. It was found that products from the general group are widely used in agriculture. Authors have found that products from a special group can only be made from biodegradable polymers with a controlled decomposition period in the soil, their use contributes to increasing the productivity of crops. (Conclusions) It was found that biodegradable polymer materials, along with environmental safety, have mechanical properties that allow them producing products that do not carry significant loads during operation. We have shown that the creation of responsible products (machine parts) from biodegradable polymers requires an increase in their strength properties, which is achievable by creating composites based on them. It was found that the technological complexity of their manufacture and high cost are the limiting factors for the widespread use of biodegradable polymers at this stage.


2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.


Author(s):  
Rike Brendgen ◽  
Carsten Graßmann ◽  
Thomas Grethe ◽  
Boris Mahltig ◽  
Anne Schwarz-Pfeiffer

AbstractPolyvinyl butyral is used in safety glass interlayers, mainly in car windshields. Legislative regulations require a recycling of cars after their lifetime and therefore also their safety glass. This causes the availability of recycled polyvinyl butyrate (r-PVB) originated from safety glass interlayers. Due to deteriorated optical properties, such as the transparency, and unknown amounts of plasticizers, it is challenging to reuse the recycled material in new windshields. Therefore, it is of particular interest to find new fields of application for r-PVB, such as the usage as a textile coating. In this research, r-PVB was investigated as a material for yarn coating. Polyester and polyamide mono- and multifilament yarns were coated continuously with solely a polymer dispersion and with mixtures of crosslinking agent and polymer dispersion. Crosslinked r-PVB coatings showed enhanced properties toward abrasion and chemical resistance. Coatings without the crosslinking agent showed a diminished abrasion resistance and could be washed off with ethanol. Mechanical properties of the monofilaments were influenced by the r-PVB coating in general. However, varying concentrations of the crosslinking agent did not affect the mechanical properties.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2205
Author(s):  
Han Liang ◽  
Jun Han ◽  
Chen Cao ◽  
Shuangwen Ma

Thin spray-on liner (TSL) is a surface protection technology used by spraying a polymer film, which is widely used for mine airtightness and waterproofing. A reinforcing TSL can replace steel mesh, which is a new method for roadway support. This paper reviews the development of a reinforcing TSL. Considering the deterioration of geological conditions in deep underground mining and the demand for reinforcing automation, two kinds of polymeric reinforcing TSL (RPTSL) materials are developed. The mechanical characteristics of the new TSL materials are studied experimentally. Results show that the average compressive strength, tensile strength, cohesion, and internal friction angle of the two TSL materials are 52 and 32 MPa, 12 and 8 MPa, 6.2 and 17.2 MPa, and 33.6° and 25.9°, respectively. The bonding strength between the two materials and coal is greater than the tensile strength of coal itself, and the mechanical properties of the material for comparison are lower than those of both materials. Based on the TSL support mechanism, we examine the application of the two TSL materials to the mining environment and compare the mechanical properties of polymer materials and cement-based materials. The advantages of polymer materials include versatile mechanical properties, good adhesion, and high early strength. This study provides a new support material to replace steel mesh for roadway surface support, which satisfies the needs of different surface support designs under complex geological conditions, and promotes the automation of roadway support.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2588
Author(s):  
Mansuri M. Tosif ◽  
Agnieszka Najda ◽  
Aarti Bains ◽  
Grażyna Zawiślak ◽  
Grzegorz Maj ◽  
...  

In recent years, scientists have focused on research to replace petroleum-based components plastics, in an eco-friendly and cost-effective manner, with plant-derived biopolymers offering suitable mechanical properties. Moreover, due to high environmental pollution, global warming, and the foreseen shortage of oil supplies, the quest for the formulation of biobased, non-toxic, biocompatible, and biodegradable polymer films is still emerging. Several biopolymers from varied natural resources such as starch, cellulose, gums, agar, milk, cereal, and legume proteins have been used as eco-friendly packaging materials for the substitute of non-biodegradable petroleum-based plastic-based packaging materials. Among all biopolymers, starch is an edible carbohydrate complex, composed of a linear polymer, amylose, and amylopectin. They have usually been considered as a favorite choice of material for food packaging applications due to their excellent forming ability, low cost, and environmental compatibility. Although the film prepared from bio-polymer materials improves the shelf life of commodities by protecting them against interior and exterior factors, suitable barrier properties are impossible to attain with single polymeric packaging material. Therefore, the properties of edible films can be modified based on the hydrophobic–hydrophilic qualities of biomolecules. Certain chemical modifications of starch have been performed; however, the chemical residues may impart toxicity in the food commodity. Therefore, in such cases, several plant-derived polymeric combinations could be used as an effective binary blend of the polymer to improve the mechanical and barrier properties of packaging film. Recently, scientists have shown their great interest in underutilized plant-derived mucilage to synthesize biodegradable packaging material with desirable properties. Mucilage has a great potential to produce a stable polymeric network that confines starch granules that delay the release of amylose, improving the mechanical property of films. Therefore, the proposed review article is emphasized on the utilization of a blend of source and plant-derived mucilage for the synthesis of biodegradable packaging film. Herein, the synthesis process, characterization, mechanical properties, functional properties, and application of starch and mucilage-based film are discussed in detail.


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