scholarly journals Influence of Lignocellulosic Waste Pre-Treatment on the Characteristics of Bond Rupture

2019 ◽  
Vol 11 (17) ◽  
pp. 4784 ◽  
Author(s):  
Štěpán Hýsek ◽  
Jaroslav Čermák ◽  
Martin Lexa
Keyword(s):  
Mechanical Properties ◽  
Crop Residues ◽  
Particle Surface ◽  
Microscopic Analysis ◽  
Raw Material ◽  
Bond Rupture ◽  
Post Harvest ◽  
Rupture Area ◽  
Suitable Treatment ◽  
Pre Treatment

Post-harvest crop residues are an interesting raw material for the production of composite materials. However, their surface often contains waxy and siliceous substances, which can cause adhesion problems. Therefore, various surface pre-treatment methods have been developed to increase the surface tension of these particles and hence to improve adhesive adhesion. The influence of hydrothermal, chemical, plasma and enzymatic treatment was investigated. The aim of the paper is to evaluate the effect of pre-treatments of post-harvest crop residues on the nature of joint failure and adhesive dispersion on the particles. The evaluation is based on microscopic analysis of particles obtained from the rupture area after internal bonding tests. The nature of bond failure and adhesive dispersion on the particle surface is evaluated. The results show a clear influence of material pre-treatment on the failure bond of the bond and, to a large extent, correlate with the mechanical properties of composites published in previous studies. The most suitable treatment appears to be a plasma treatment at a properly adjusted intensity. Conversely, the unsuitable treatment was alkaline, which, although it increased adhesion, deteriorated the overall mechanical properties. Hydrothermal treatment could be also considered as an industrially suitable method.

scholarly journals The Utilization of Crop Residues as Forest Protection: Predicting the Production of Wheat and Rapeseed Residues

2020 ◽  
Vol 12 (14) ◽  
pp. 5828
Author(s):  
Petra Hýsková ◽  
Štěpán Hýsek ◽  
Vilém Jarský
Keyword(s):  
Ecosystem Services ◽  
Crop Residues ◽  
Raw Material ◽  
Agricultural Crops ◽  
The European Union ◽  
Forest Protection ◽  
Harvest Residues ◽  
Post Harvest ◽  
Future Production ◽  
Harvest Residue

Deforestation is a global threat in the form of the reduction of all of the ecosystem services provided to humans by forest ecosystems. For this reason, this article deals with the protection of forest ecosystem services by searching for a substitute for wood biomass. In recent years, the post-harvest residues of agricultural crops have been used mainly for energy and material uses. If this raw material is to be used industrially in the long term, we must have an idea of its future production. In most studies, predictions of future post-harvest residue productions are resolved in terms of the availability for energy sectors. This paper deals with the total amount of produced post-harvest residues that can be taken from the field; the post-harvest residue production for selected sectors is not subtracted from the overall prediction. Post-harvest residue production was estimated using the residue to product ratio (RPR), wherein the RPR coefficient was calculated for the monitored crops in each year, and the post-harvest residue production was subsequently calculated in each year according to the conversion rate characteristic for each year. The production of two widespread agricultural crops—wheat and rapeseed—was predicted. Linear regression models were used for the estimations. Based on these models, we predict the production of 58.3 million tonnes of post-harvest wheat residues and 22.4 million tonnes of post-harvest rapeseed residues in 2030 in the European Union. In the Czech Republic, we predict the production of 1.8 million tonnes of post-harvest wheat residues and 1.3 million tonnes of post-harvest rapeseed residues. The presented results can be used as the basis for further considerations of the material use of post-harvest residues and for the substitution of wood with these residues.

scholarly journals Lignocellulose Nanofibre Obtained from Agricultural Wastes of Tomato, Pepper and Eggplants Improves the Performance of Films of Polyvinyl Alcohol (PVA) for Food Packaging

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3043
Author(s):  
Isabel Bascón-Villegas ◽  
Mónica Sánchez-Gutiérrez ◽  
Fernando Pérez-Rodríguez ◽  
Eduardo Espinosa ◽  
Alejandro Rodríguez
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Antioxidant Activity ◽  
Polyvinyl Alcohol ◽  
Young’S Modulus ◽  
Food Packaging ◽  
Young's Modulus ◽  
Raw Material ◽  
Elongation At Break ◽  
Pre Treatment

Films formulated with polyvinyl alcohol (PVA) (synthetic biopolymer) were reinforced with lignocellulose nanofibres (LCNF) from residues of vegetable production (natural biopolymer). The LCNF were obtained by mechanical and chemical pre-treatment by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and added to the polyvinyl alcohol (polymer matrix) with the aim of improving the properties of the film for use in food packaging. The mechanical properties, crystallinity, thermal resistance, chemical structure, antioxidant activity, water barrier properties and optical properties (transparency and UV barrier), were evaluated. In general, with the addition of LCNF, an improvement in the studied properties of the films was observed. In terms of mechanical properties, the films reinforced with 7% LCNF TEMPO showed the best results for tensile strength, Young’s modulus and elongation at break. At the same LCNF proportion, the thermal stability (Tmax) increased between 5.5% and 10.8%, and the antioxidant activity increased between 90.9% and 191.8%, depending on the raw material and the pre-treatment used to obtain the different LCNF. Finally, a large increase in UV blocking was also observed with the addition of 7% LCNF. In particular, the films with 7% of eggplant LCNF showed higher performance for Young’s modulus, elongation at break, thermal stability and UV barrier. Overall, results demonstrated that the use of LCNF generated from agricultural residues represents a suitable bioeconomy approach able to enhance film properties for its application in the development of more sustainable and eco-friendly food packaging systems.

scholarly journals The influence of fibre pre-treatment on the mechanical properties of the geopolymer composites

2020 ◽  
Vol 322 ◽  
pp. 01012
Author(s):  
Kinga Korniejenko ◽  
Beata Figiela ◽  
Hana Šimonová ◽  
Barbara Kucharczyková ◽  
Martin Duarte Guigou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Visual Analysis ◽  
Treatment Method ◽  
Positive Influence ◽  
Natural Fibres ◽  
Raw Material ◽  
Ambient Temperatures ◽  
Pre Treatment ◽  
Geopolymer Composites

This article aims to analyse the long-term influence of the pre- treatment method on mechanical properties such as the compressive strength of geopolymer composites reinforced with short natural fibres (length of around 5 mm). This paper presents the behaviour of sodium activator-synthesised fly ash geopolymer containing natural fibres at ambient temperatures. Fly ash from the Skawina coal power plant (located in: Skawina, Lesser Poland, Poland) was used as a raw material. The chemical composition of the fly ash was typical for class F. The article evaluated the methods of pre-treatment of the fibres on the mechanical properties of the geopolymer composites. It compares the plain specimens and composites with fibres pre-treated in water and alkali solutions as well as with fibres without any pre-treatment. The fibres were added at the amount of 1% by weight. The investigation was made by visual analysis and the testing of mechanical properties (compressive and flexural strength at ambient temperature) after 6 months. The achieved results do not confirm the positive influence of the fibre pre-treatment on the mechanical properties of the composites.

scholarly journals Recent Tendencies in Waste-Based Aggregates in Concrete Production

2021 ◽  
Vol 31 (2) ◽  
pp. 43-62
Author(s):  
Marta Thomas
Keyword(s):  
Mechanical Properties ◽  
Building Material ◽  
Raw Material ◽  
Continuous Increase ◽  
Aggregate Production ◽  
Concrete Aggregates ◽  
Concrete Production ◽  
Renewable Raw Material ◽  
Pre Treatment ◽  
European Standards

Abstract The development of construction and the growing popularity of concrete as a building material cause a continuous increase in the demand for non-renewable raw material such as aggregate. This paper aims to analyse the possibility of using various alternative aggregates for the production of concrete. In the first part of article a detailed analysis of the European aggregate production has thus been carried out and the requirements for concrete aggregates according to European Standards have been also presented. One of the goals of sustainable waste management is to reduce landfills by finding new ways to reuse and disposing waste. Therefore in the second part of article the waste-based aggregates have been analysed. Moreover, various types of alternative aggregates such as recycled and manufactured aggregates are discussed in detail. The article presents also the properties of selected alternative aggregates with a proposal of pre-treatment. Based on the presented analyses it can be concluded that each new waste that is sourced as aggregate in concrete should undergo detailed testing because of the different chemical and mechanical properties of various waste aggregates. Hence, specific research for each waste should be undertaken.

scholarly journals Pre-treatments of pre-consumer cotton-based textile waste for production of textile fibres in the cold NaOH(aq) and cellulose carbamate processes

Cellulose ◽  
2021 ◽  
Author(s):  
Marjo Määttänen ◽  
Maria Gunnarsson ◽  
Helena Wedin ◽  
Sara Stibing ◽  
Carina Olsson ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Raw Material ◽  
Textile Waste ◽  
Future Studies ◽  
Degree Of Polymerisation ◽  
Textile Fibres ◽  
Cellulose Carbamate ◽  
Regenerated Fibres ◽  
Inorganic Content

AbstractRecycling of textiles is of importance due to the large amount of waste generated from the increasing consumption and use worldwide. Cotton-rich pre-consumer textiles are considered as potential raw material for production of man-made regenerated fibres, but demands purification from the blends with synthetic fibres as well as the dyes and finishing chemicals. In this study we explore the use of different pre-treatments of pre-consumer textiles to meet specific parameters for production of fibres in the cold NaOH(aq) or cellulose carbamate process. The pre-treatments consisted of different bleaching sequences and were performed on both uncoloured and coloured pre-consumer textiles. For the uncoloured textile, degree of polymerisation and amount of inorganic content was efficiently reduced making the material suitable for both the cold NaOH(aq) and the cellulose carbamate process. In case of the coloured textile, the pre-treatments were able to remove the dye and decrease the inorganic content as well as reduce the degree of polymerisation but only sufficiently enough for production of fibres in the cellulose carbamate process. The work was able to prove a fibre-to-fibre concept while further optimisation of the regeneration steps is expected to improve the mechanical properties of the produced fibres in future studies.

scholarly journals Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1242
Author(s):  
Olga Mysiukiewicz ◽  
Paulina Kosmela ◽  
Mateusz Barczewski ◽  
Aleksander Hejna
Keyword(s):  
Mechanical Properties ◽  
Melt Flow Index ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Metal Composites ◽  
Pre Treatment ◽  
The Impact ◽  
Properties Of Composites

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

MECHANICAL PROPERTIES OF ROTATIONALLY MOLDED PET MICROFIBRIL REINFORCED COMPOSITES

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4613-4618 ◽  
Author(s):  
R. J. T. LIN ◽  
D. BHATTACHARYYA ◽  
S. FAKIROV
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Industry ◽  
Polymer Processing ◽  
Raw Material ◽  
Medium Density ◽  
Reinforced Composites ◽  
Rotational Molding ◽  
Commercial Scale ◽  
Strength And Stiffness ◽  
Set Up

Being a fast growing plastic manufacturing industry, rotational molding has been using the linear polyethylenes extensively as the raw material. As these materials have shown insufficient mechanical properties for certain applications where strength and stiffness of the products are the main concerns, worldwide rotational molders have expressed a need for stronger and stiffer materials to be available for rotomolding. A possible attractive solution may be the recently developed microfibril reinforced composites (MFCs). Blends of linear medium density polyethylene/polyethylene terephthalate (LMDPE/PET) with an MFC structure are manufactured on a commercial-scale set-up and thereafter used in rotational molding. The samples are characterized morphologically and tested mechanically. The results obtained show that the MFC-concept has good application opportunities in the polymer processing including rotational molding.

Intrinsic mechanical properties of the extracellular matrix affect the behavior of pre-osteoblastic MC3T3-E1 cells

2006 ◽  
Vol 290 (6) ◽  
pp. C1640-C1650 ◽  
Author(s):  
Chirag B. Khatiwala ◽  
Shelly R. Peyton ◽  
Andrew J. Putnam
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Focal Adhesions ◽  
Microscopic Analysis ◽  
Maximal Activity ◽  
Type I ◽  
Cell Functions ◽  
Collagen Density ◽  
Cells Cultured ◽  
In Cells

Mechanical cues present in the ECM have been hypothesized to provide instructive signals that dictate cell behavior. We probed this hypothesis in osteoblastic cells by culturing MC3T3-E1 cells on the surface of type I collagen-modified hydrogels with tunable mechanical properties and assessed their proliferation, migration, and differentiation. On gels functionalized with a low type I collagen density, MC3T3-E1 cells cultured on polystyrene proliferated twice as fast as those cultured on the softest substrate. Quantitative time-lapse video microscopic analysis revealed random motility speeds were significantly retarded on the softest substrate (0.25 ± 0.01 μm/min), in contrast to maximum speeds on polystyrene substrates (0.42 ± 0.04 μm/min). On gels functionalized with a high type I collagen density, migration speed exhibited a biphasic dependence on ECM compliance, with maximum speeds (0.34 ± 0.02 μm/min) observed on gels of intermediate stiffness, whereas minimum speeds (0.24 ± 0.03 μm/min) occurred on both the softest and most rigid (i.e., polystyrene) substrates. Immature focal contacts and a poorly organized actin cytoskeleton were observed in cells cultured on the softest substrates, whereas those on more rigid substrates assembled mature focal adhesions and robust actin stress fibers. In parallel, focal adhesion kinase (FAK) activity (assessed by detecting pY397-FAK) was influenced by compliance, with maximal activity occurring in cells cultured on polystyrene. Finally, mineral deposition by the MC3T3-E1 cells was also affected by ECM compliance, leading to the conclusion that altering ECM mechanical properties may influence a variety of MC3T3-E1 cell functions, and perhaps ultimately, their differentiated phenotype.

Use of Sugarcane Bagasse Ashes as Raw Material in the Replacement of Fluxes for Applications on Porcelain Tile

2016 ◽  
Vol 881 ◽  
pp. 383-386 ◽  
Author(s):  
Raimundo J.S. Paranhos ◽  
Wilson Acchar ◽  
Vamberto Monteiro Silva
Keyword(s):  
Mechanical Properties ◽  
Environmental Impact ◽  
Physical Properties ◽  
Sugarcane Bagasse ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Raw Material ◽  
The Cost ◽  
Potential Use ◽  
Porcelain Tile

This study evaluated the potential use of Sugarcane Bagasse Ashes (SBA) as a flux, replacing phyllite for the production of enamelled porcelain tile. The raw materials of the standard mass components and the SBA residue were characterized by testing by XRF, XRD, AG, DTA and TGA. Test samples were fabricated, assembled in lots of 3 units and sintered at temperatures of 1150 ° C to 1210 ° C. The results of the physical properties, mechanical properties and SEM of the sintered samples, showed that the formulation, G4 - in which applied 10% of SBA replacing phyllite, sintering temperature 1210 ° C showed better performance as the previously mentioned properties due to the formation of mullite crystals, meeting the prerequisites of standards for enamelled porcelain tile, while reducing the environmental impact and the cost of production.

scholarly journals Characterization and Analysis of the Carbonation Process of a Lime Mortar Obtained from Phosphogypsum Waste

2021 ◽  
Vol 18 (12) ◽  
pp. 6664
Author(s):  
María Isabel Romero-Hermida ◽  
Antonio María Borrero-López ◽  
Vicente Flores-Alés ◽  
Francisco Javier Alejandre ◽  
José María Franco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mineralogical Composition ◽  
Barium Sulphate ◽  
Negative Influence ◽  
Raw Material ◽  
Porous System ◽  
Waste Products ◽  
Liesegang Rings ◽  
Carbonation Process ◽  
Ultrasonic Propagation

This work addresses the reuse of waste products as a raw material for lime putties, which are one of the components of mortar. 1:3 Lime/sand mortars very similar to conventional construction mortars were prepared using a lime putty obtained from the treatment of phosphogypsum with sodium hydroxide. The physical, rheological and mechanical properties of this phosphogypsum-derived mortar have been studied, as well as the mineralogical composition, microstructure by scanning electron microscope (SEM) and curing process by monitoring carbonation and ultrasonic propagation velocity. Considering the negative influence of sulphates on the hardened material, the behaviour of the material after sulphates precipitation by adding barium sulphate was additionally tested. Carbonation progressed from the outside to the inside of the specimen through the porous system by Liesegang rings patterns for mortars with soluble sulphates, while the carbonation with precipitated sulphates was controlled by diffusion-precipitation. Overall, the negative influence of low-sulphate contents on the mechanical properties of mortars was verified. It must be highlighted the importance of their precipitation to obtain adequate performance.

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