scholarly journals The Choice of Recycling Methods for Single-Polymer Polyester Composites

2018 ◽  
Vol 55 (4) ◽  
pp. 658-665 ◽  
Author(s):  
Katarzyna Gawdzinska ◽  
Marcin Nabialek ◽  
Andrei Victor Sandu ◽  
Katarzyna Bryll

This work has described the production of single-polymer composites by the film-stacking method. Two types of single-polymer composites with different mass fractions of the polyester reinforcement phase (10% and 20%) and the PETG matrix were investigated. The produced composites were subsequently recycled by injection moulding, pressing, and extrusion. Selected properties of the processed composites were determined: density, viscosity-average molecular weight, impact resistance, and tensile strength. The work done in this paper has demonstrated the benefits and drawbacks of each recycling method for these materials. The selected properties of single-polymer polyester composites and single-polymer polyester composites that were recycled by extrusion have also been compared.

2022 ◽  
Vol 58 (4) ◽  
pp. 28-36
Author(s):  
Velmurugan Natarajan ◽  
Ravi Samraj ◽  
Jayabalakrishnan Duraivelu ◽  
Prabhu Paulraj

This study aims to reveal the consequence of thickness reinforcement on Fiber Laminates (Polyester Resin, Glass Fiber, Aluminum, and Bentonite) and to see if it can enhance the mechanical properties and resistance of laminates. Glass fiber reinforced polymer composites have recently been used in automotive, aerospace, and structural applications where they will be safe for the application s unique shape. Hand layup was used to fabricate three different combinations, including Aluminium /Glass fiber reinforced polyester composites (A/GFRP), Bentonite/Glass fiber reinforced polyester composites (B/GFRP), and Aluminium&Bentonie/Glass fiber reinforced polyester composites (AB/GFRP). Results revealed that AB/GFRP had better tensile strength, flexural strength, and hardness than GFRP and A/GFRP. Under normal atmospheric conditions and after exposure to boiling water, hybrid Aluminium&Bentonite and glass fiber-reinforced nanocomposites have improved mechanical properties than other hybrid composites. After exposure to temperature, the flexural strength, tensile strength and stiffness of AB/GFRP Composites are 40 % higher than A/GFRP and 17.44% higher than B/GFRP Composites.


1981 ◽  
Vol 54 (2) ◽  
pp. 374-402 ◽  
Author(s):  
C. K. Riew

Abstract Amine terminated reactive liquid polymers (AT-RLP) are synthesized from corresponding carboxyl terminated reactive liquid polymers (CT-RLP) and diamines. The CT-RLPs have a functionality of close to two, the average molecular weight ranging from 2500 to 4000, and Brookfield viscosity ranging from 30 to 600 Pa · s at 27°C. AT-RLPs made from the CT-RLPs have about the same physical properties as the CT-RLPs given above. N-(2-aminoethyl)piperazine (AEP2) is the best diamine among the diamines tried to produce low viscosity and low molecular weight AT-RLPs. Structure of end-groups of AT-RLP is unequivocally identified as a secondary amide and a secondary amine group resulting from the reaction of carboxyl end-groups of CT-RLP and a primary amine group of AEP,. The AT-RLP can be used as a modifier for epoxy resins at room or elevated temperatures to produce castable formulations with properties ranging from plastics to elastomers. The formulations may be useful as a modifier for improvement of crack and/or impact resistance of normally brittle epoxy plastics, as castable elastomers, paints and coatings, sealants, adhesives, especially as solventless adhesives for conveyor belts, hoses, shoes, and as binders for woven or non-woven fibers and cords.


Author(s):  
Vipul Sharma ◽  
Rajiv Kumar ◽  
Karan Vohra ◽  
Kapil Chopra

Use of natural fibres as reinforcement in polymeric composites has been increased during last few decades. They are potential alternatives to synthetic fibres due to their excellent properties like light in weight, biodegradable, abundant, satisfactory strength etc. Various parts of automobiles are being made by natural fibres that improved fuel efficiency and reduced emissions. The present study focuses on developing new polymer composites by reinforcing walnut shell particulate on the basis of different weight fractions. Mechanical characterization was done for the developed composites which include evaluation of tensile strength, impact strength and hardness. Different weight fractions of walnut shell particulate were used including 0%, 10%, 15% and 20%. Maximum tensile strength was achieved in case of 10% walnut shell reinforced composites. Maximum impact strength and hardness were achieved in case of 20% and 15% reinforcement respectively.


2017 ◽  
Vol 68 (9) ◽  
pp. 2034-2038 ◽  
Author(s):  
Katarzyna Bryll ◽  
Katarzyna Gawdzinska ◽  
Marcin Nabialek ◽  
Patrycja Pawlowska

In present study the authors determine the impact of active environment on destruction processes developing in single polymer polyester composites. The processes impact on the structure and selected (e.g. viscosity) mechanical features of these composites were examined. The work included the following stages: manufacturing of ordered and disordered linear fiber single polyester composites, preparation of samples in accordance with applicable testing standards, performing composites� degradation tests in different media (distilled water and sea water at 30oC,). Literature review has shown that this kind of material has not been examined in reference to active media impact on degradation processes. This work is part of the research on discussed composites� properties and recycling.


Cellulose ◽  
2021 ◽  
Vol 28 (15) ◽  
pp. 9547-9566 ◽  
Author(s):  
Kaniz Moriam ◽  
Daisuke Sawada ◽  
Kaarlo Nieminen ◽  
Michael Hummel ◽  
Yibo Ma ◽  
...  

AbstractThe production of sustainable and high-performance fabrics requires high mechanical strength of the individual (staple) fibers. Although Ioncell fibers already exhibit higher fiber strength than commercial man-made cellulose fibers or cotton fibers, we further aimed to increase both strength and toughness to gradually approach synthetic fibers in these properties. Decisive factors for the achievable mechanical properties of the fibers were the pulp purity, the cellulose concentration in the spinning solution and length-to-diameter (L/D) ratio of the cylindrical part of the spinneret. The absence of low molecular weight fractions in combination with an increased average molecular weight had the highest impact on the achievement of both high strength and toughness. Using a spinneret with a high L/D ratio, it was possible to spin Ioncell fibers with a tensile strength of 925 MPa (61.5 cN/tex) and a modulus of toughness of 83.3 MPa (55.5 J/g). According to a fluid dynamic simulation, uniformly longer molecular cellulose chains in combination with a longer cylindrical capillary promoted an effective alignment of the cellulose molecules inside the spinneret capillary before entering the airgap, thus creating the conditions for a simultaneous increase in tensile strength and elongation i.e. toughness of the fiber. Mechanistically, high fiber toughness is caused by the structural parameters in longitudinal direction, in particular by a higher tilt angle, a longer periodicity of the lamellar plane and lower micro void orientation. In summary, we have developed lyocell-type fibers with high strength and toughness, which can potentially be used as a surrogate for synthetic fibers. Graphic abstract


2009 ◽  
Vol 87-88 ◽  
pp. 228-232
Author(s):  
Li Yun Zheng ◽  
Zhi Min Liu ◽  
Ya Jun Zhao

To enhance the mechanical property and the bioactivity of composites, nano-hydroxyapatite (n-HA) modified monomer casting nylon-6 (n-HA/N) composites were prepared by in situ polymerization. During the synthesis of n-HA/N composite, the n-HA and caprolactam were mixed, melt and placed in the field of ultrasonic radiation. The differences between composite with ultrasonic and without ultrasonic were investigated. The tensile strength and the viscosity average molecular weight of the nylon matrix were measured. The results show that the molecular weight of the nylon matrix decreased firstly and it had the lowest value when the content of nano-hydroxyapatite was 1.6 wt.%. After that the molecular weight increased and then it began to decrease when it reached the highest value. But the tensile strength of the n-HA/N composite were improved. The ultrasonic dispersion made the n-HA more evenly dispersed in the nylon and increased the mechanical properties of the n-HA/N composites significantly. The bioactivity and moisture absorption of n-HA/N composites in simulated body fluid (SBF) were examined and compared to pure nylon. What's more, Fourier transform infrared spectrometer was used to characterize the structure of the materials formed on the surface of the composite. The results showed that moisture absorption of the n-HA/N composites was lower than that of the pure nylon. After composites impregnated 16 days in SBF, a layer of carbon hydroxyapatite (CHA) with weak crystalline was formed on the surface of sample. This phenomenon showed that the n-HA/N composites have good bioactivity.


Author(s):  
C. E. Cluthe ◽  
G. G. Cocks

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.


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.    


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