Bio-based polyhydroxyalkanoates blends and composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Samy A. Madbouly
Keyword(s):  
Mechanical Properties ◽  
Functional Materials ◽  
Cost Effective ◽  
Production Method ◽  
Industrial Applications ◽  
Mechanical And Thermal Properties ◽  
Wide Range ◽  
High Production ◽  
High Production Cost ◽  
New Generation

Abstract Polyhydroxyalkanoates (PHAs) are linear semicrystalline polyesters produced naturally by a wide range of microorganisms for carbon and energy storage. PHAs can be used as replacements for petroleum-based polyethylene (PE) and polypropylene (PP) in many industrial applications due to their biodegradability, excellent barrier, mechanical, and thermal properties. The overall industrial applications of PHAs are still very limited due to the high production cost and high stiffness and brittleness. Therefore, new novel cost-effective production method must be considered for the new generation of PHAs. One approach is based on using different type feedstocks and biowastes including food byproducts and industrial and manufacturing wastes, can lead to more competitive and cost-effective PHAs products. Modification of PHAs with different function groups such as carboxylic, hydroxyl, amine, epoxy, etc. is also a relatively new approach to create new functional materials with different industrial applications. In addition, blending PHA with biodegradable materials such as polylactide (PLA), poly(ε-caprolactone) (PCL), starch, and distiller’s dried grains with solubles (DDGS) is another approach to address the drawbacks of PHAs and will be summarized in this chapter. A series of compatibilizers with different architectures were successfully synthesized and used to improve the compatibility and interfacial adhesion between PHAs and PCL. Finer morphology and significantly improvement in the mechanical properties of PHA/PCL blends were observed with a certain type of block compatibilizer. In addition, the improvement in the blend morphology and mechanical properties were found to be strongly influenced by the compatibilizer architecture.

A Short Review on Recent Development of Laccase Immobilization on Different Support Materials

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Norsyafiqah Amalina Ahmad Jafri ◽  
◽  
Roshanida A. Rahman ◽  
Noorhalieza Ali ◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Short Review ◽  
Industrial Applications ◽  
Innovative Strategies ◽  
Support Materials ◽  
High Production ◽  
Efficient Recovery ◽  
High Production Cost ◽  
Laccase Immobilization

Laccase is a bio catalytic agent and multi-copper enzyme containing oxidases that are potentially great for oxidizing large number of phenolic and non-phenolic compounds. However, drawbacks do arise when laccase use in large scale; low in stability, high production cost, non-reusability, sensitive towards denaturing and poor storage ability of free enzymes. These problems lead to the progress in laccase immobilization in order to facilitate the efficient recovery and re-use of the enzyme, thus enabling cost-effective in continuous processes. Apart from discussing on different methods in laccase immobilization such as entrapment, encapsulation and cross-linking in general, we have reviewed a recent development in laccase immobilization on different supports or carriers binding (natural and synthetic). Future works are recommended to focus on innovative strategies on the modified supports to improve the enzyme immobilization as well as sensible entrapment techniques for industrial applications.

A review on graphene-based polymer composite coatings for the corrosion protection of metals

2019 ◽  
Vol 37 (4) ◽  
pp. 343-363 ◽  
Author(s):  
Ahmed Khalid Hussain ◽  
Izman Sudin ◽  
Uday M. Basheer ◽  
Mohd Zamri Mohd Yusop
Keyword(s):  
Polymer Composite ◽  
Composite Coatings ◽  
Cost Effective ◽  
Industrial Applications ◽  
Surface Protection ◽  
Coating Application ◽  
High Performing ◽  
Wide Range ◽  
Application Techniques ◽  
New Generation

AbstractGraphene-based coating is an emerging field that focuses on developing advanced coatings by exploiting new generation materials with superior properties. Researchers are striving to develop coatings that are cost-effective, easy to prepare and highly effective by integrating graphene with a wide range of suitable materials for surface protection applications. In this critical review, different types of high performing graphene-based polymer composite coatings have been described for anticorrosion application. An in-depth survey on methods of preparation, coating application techniques and their influence on the corrosion behavior of coatings is presented briefly. Newly developed strategies to enhance the protection efficiency of graphene-polymer matrix coatings are also covered concisely. The authors hope that this review will assist prospective academicians and researchers in developing novel highly efficient graphene-based anticorrosion composite coatings for industrial applications.

scholarly journals Effects of a Twin-Screw Extruder Equipped with a Molten Resin Reservoir on the Mechanical Properties and Microstructure of Recycled Waste Plastic Polyethylene Pellet Moldings

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1058
Author(s):  
Hikaru Okubo ◽  
Haruka Kaneyasu ◽  
Tetsuya Kimura ◽  
Patchiya Phanthong ◽  
Shigeru Yao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Value Added ◽  
Industrial Applications ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Polymer Properties ◽  
Wide Range ◽  
Twin Screw ◽  
Recycled Plastics

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.

scholarly journals Fermentative Production of Mannosylerythritol Lipids using Sweetwater as Waste Substrate by Pseudozyma antarctica (MTCC 2706)

2021 ◽  
Vol 58 (4) ◽  
pp. 246-258
Author(s):  
Jayata Mawani ◽  
Jagruti Jadhav ◽  
Amit Pratap
Keyword(s):  
Soybean Oil ◽  
Industrial Applications ◽  
Commercial Production ◽  
Liquid Chromatography Mass Spectrometry ◽  
Mannosylerythritol Lipids ◽  
Pseudozyma Antarctica ◽  
Fermentative Production ◽  
Oil Concentration ◽  
High Production ◽  
High Production Cost

Abstract Mannosylerythritol lipids are glycolipid biosurfactants with promising industrial applications. However, their commercial production is hindered due to its high production cost. The current study investigates the use of sweetwater, a by-product of the fat-splitting industry in combination with soybean oil for the production of mannosylerythritol lipids using Pseudozyma antarctica (MTCC 2706). The optimum sweetwater and soybean oil concentration of 22% and 7% (w/v) yielded 7.52 g L–1and 21.5 g L–1 mannosylerythritol lipids at shake flask and fermenter level respectively. The structure and functional groups of mannosylerythritol lipids were confirmed by fourier transform infrared (FTIR) spectroscopy, liquid chromatography-mass spectrometry (LC/MS) and 1H- and 13C-nuclear magnetic resonance (NMR) analysis. Surfactant properties, such as surface tension, critical micelle concentration, foaming and emulsification of mannosylerythritol lipids were also explored.

scholarly journals Designing a new generation of expression toolkits for engineering of green microalgae; robust production of human interleukin-2

Bioimpacts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 259-268
Author(s):  
Jaber Dehghani ◽  
Khosro Adibkia ◽  
Ali Movafeghi ◽  
Mohammad M. Pourseif ◽  
Yadollah Omidi
Keyword(s):  
Recombinant Proteins ◽  
Interleukin 2 ◽  
Cost Effective ◽  
Total Soluble Protein ◽  
Post Translational Modifications ◽  
Unstable Gene ◽  
Protein Synthesis Machinery ◽  
Wide Range ◽  
High Transformation ◽  
New Generation

Introduction: Attributable to some critical features especially the similarity of the protein synthesis machinery between humans and microalgae, these microorganisms can be utilized for the expression of many recombinant proteins. However, low and unstable gene expression levels prevent the further development of microalgae biotechnology towards protein production. Methods: Here, we designed a novel "Gained Agrobacterium-2A plasmid for microalgae expression" (named GAME plasmid) for the production of the human interleukin-2 using three model microalgae, including Chlamydomonas reinhardtii, Chlorella vulgaris, and Dunaliella salina. The GAME plasmid harbors a native chimeric hsp70/Int-1/rbcS2 promoter, the microalgae specific Kozak sequence, a novel hybrid 2A peptide, and Int-1 and Int-3 of the rbcS2 gene in its expression cassette. Results: The obtained data confirmed that the GAME plasmid can transform the microalgae with high transformation frequency. Molecular and proteomic analyses revealed the stable and robust production of the hIL-2 by the GAME plasmid in the microalgae. According to the densimetric analysis, the microalgae can accumulate the produced protein about 0.94% of the total soluble protein content. The ELISA data confirmed that the produced hIL-2 possesses the same conformation pattern with the acceptable biological activity found naturally in humans. Conclusion: Most therapeutic proteins need post-translational modifications for their correct conformation, biological function, and half-life. Accordingly, microalgae could be considered as a cost-effective and more powerful platform for the production of a wide range of recombinant proteins such as antibodies, enzymes, hormones, and vaccines.

Micro pulling down growth of very thin shape memory alloys single crystals

2017 ◽  
Vol 10 (01) ◽  
pp. 1740003 ◽  
Author(s):  
I. López-Ferreño ◽  
J. San Juan ◽  
T. Breczewski ◽  
G. A. López ◽  
M. L. Nó
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloys ◽  
Single Crystal ◽  
Shape Memory ◽  
Single Crystals ◽  
Functional Materials ◽  
Small Scale ◽  
Cylindrical Shape ◽  
Minimum Diameter ◽  
Wide Range

Shape memory alloys (SMAs) have attracted much attention in the last decades due to their thermo-mechanical properties such as superelasticity and shape memory effect. Among the different families of SMAs, Cu–Al–Ni alloys exhibit these properties in a wide range of temperatures including the temperature range of 100–200[Formula: see text]C, where there is a technological demand of these functional materials, and exhibit excellent behavior at small scale making them more competitive for applications in Micro Electro-Mechanical Systems (MEMS). However, polycrystalline alloys of Cu-based SMAs are very brittle so that they show their best thermo-mechanical properties in single-crystal state. Nowadays, conventional Bridgman and Czochralski methods are being applied to elaborate single-crystal rods up to a minimum diameter of 1[Formula: see text]mm, but no works have been reported for smaller diameters. With the aim of synthesizing very thin single-crystals, the Micro-Pulling Down ([Formula: see text]-PD) technique has been applied, for which the capillarity and surface tension between crucible and the melt play a critical role. The [Formula: see text]-PD method has been successfully applied to elaborate several cylindrical shape thin single-crystals down to 200[Formula: see text][Formula: see text]m in diameter. Finally, the martensitic transformation, which is responsible for the shape memory properties of these alloys, has been characterized for different single-crystals. The experimental results evidence the good quality of the grown single-crystals.

scholarly journals Fabrication and Characterization of Polylactic Acid Electrospun Scaffolds Modified with Multi-Walled Carbon Nanotubes and Hydroxyapatite Nanoparticles

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 43
Author(s):  
Athanasios Kotrotsos ◽  
Prokopis Yiallouros ◽  
Vassilis Kostopoulos
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Cost Effective ◽  
Electrospinning Process ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The solution electrospinning process (SEP) is a cost-effective technique in which a wide range of polymeric materials can be electrospun. Electrospun materials can also be easily modified during the solution preparation process (prior SEP). Based on this, the aim of the current work is the fabrication and nanomodification of scaffolds using SEP, and the investigation of their porosity and physical and mechanical properties. In this study, polylactic acid (PLA) was selected for scaffold fabrication, and further modified with multi-walled carbon nanotubes (MWCNTs) and hydroxyapatite (HAP) nanoparticles. After fabrication, porosity calculation and physical and mechanical characterization for all scaffold types were conducted. More precisely, the morphology of the fibers (in terms of fiber diameter), the surface properties (in terms of contact angle) and the mechanical properties under the tensile mode of the fabricated scaffolds have been investigated and further compared against pristine PLA scaffolds (without nanofillers). Finally, the scaffold with the optimal properties was proposed as the candidate material for potential future cell culturing.

scholarly journals Bio-Based Polyurethane Resins Derived from Tannin: Source, Synthesis, Characterisation, and Application

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1516
Author(s):  
Manggar Arum Aristri ◽  
Muhammad Adly Rahandi Lubis ◽  
Apri Heri Iswanto ◽  
Widya Fatriasari ◽  
Rita Kartika Sari ◽  
...  
Keyword(s):  
Natural Resources ◽  
Value Added ◽  
Gel Permeation Chromatography ◽  
Industrial Applications ◽  
Hot Water ◽  
Synthesis Process ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Protective Function ◽  
Wide Range

Tannins are soluble, astringent secondary phenolic metabolites generally obtained from renewable natural resources, and can be found in many plant parts, such as fruits, stems, leaves, seeds, roots, buds, and tree barks, where they have a protective function against bacterial, fungal, and insect attacks. In general, tannins can be extracted using hot water or organic solvents from the bark, leaves, and stems of plants. Industrially, tannins are applied to produce adhesives, wood coatings, and other applications in the wood and polymer industries. In addition, tannins can also be used as a renewable and environmentally friendly material to manufacture bio-based polyurethanes (bio-PUs) to reduce or eliminate the toxicity of isocyanates used in their manufacture. Tannin-based bio-PUs can improve the mechanical and thermal properties of polymers used in the automotive, wood, and construction industries. The various uses of tannins need to be put into perspective with regards to possible further advances and future potential for value-added applications. Tannins are employed in a wide range of industrial applications, including the production of leather and wood adhesives, accounting for almost 90% of the global commercial tannin output. The shortage of natural resources, as well as the growing environmental concerns related to the reduction of harmful emissions of formaldehyde or isocyanates used in the production of polyurethanes, have driven the industrial and academic interest towards the development of tannin-based bio-PUs as sustainable alternative materials with satisfactory characteristics. The aim of the present review is to comprehensively summarize the current state of research in the field of development, characterization, and application of tannin-derived, bio-based polyurethane resins. The successful synthesis process of the tannin-based bio-PUs was characterized by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), MALDI-TOF mass spectrometry, and gel permeation chromatography (GPC) analyses.

scholarly journals Comparative study of sucrose plasticised bioplastic derivatives with selected petro-plastics

2020 ◽  
Vol 12 (1) ◽  
pp. 386-394
Author(s):  
E.C. Agwamba
Keyword(s):  
Mechanical Properties ◽  
High Density Polyethylene ◽  
Production Cost ◽  
Young Modulus ◽  
Raw Material ◽  
Significant Difference ◽  
High Production ◽  
Bulk Matrix ◽  
High Production Cost ◽  
Hcl Concentration

The major setback with most bioplastics is their inherent inability to compete with Petro-plastics in terms of high production cost, and there poor mechanical properties like low tensile strength and percentage extension. This study explore the availability and affordability of mango starch as raw material for bioplastic production and compared some of its mechanical properties with High density Polyethylene (HDPE), Low density polyethylene (LDPE), polyvinyl chloride (PVC), and Polyurethane (PU). Mango starch was used to synthesize bioplastic derivatives, with variable levels of sucrose as plasticiser, aqueous HCl concentration and Carboxymethyl cellulose (CMC) as additive and the mechanical properties of the derived biofilms was measured and compared with the selected Petro-plastics films. It was observed that B1 thermoplastic derivatives have the higher young modulus of 5.658 GPa than that obtained for PVC (4.682 GPa), and PU (3.771 GPa) but show no significant difference and significantly higher than that of HDPE (0.049 GPa), and LDPE (0.063 GPa) (p < 0.05). B2 and B3 indicated a young modulus that is significantly lower than PU and PVC, but showed a young modulus that is higher than LDPE and HDPE with no significant difference (p < 0.05). The FTIR spectra indicate that hydrogen bond was formed in the bulk matrix of the bioplastic derivatives at a band region of 3600 -600 cm-1 wavenumber with broad discrete peaks. Keywords: Petro-plastics; Bioplastics; Mechanical Properties; Plasticization; Mango Starch

scholarly journals Complex Electrical Conductivity of Biotite and Muscovite Micas at Elevated Temperatures: A Comparative Study

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3513
Author(s):  
Vassilios Saltas ◽  
Despoina Pentari ◽  
Filippos Vallianatos
Keyword(s):  
Electrical Conductivity ◽  
Elevated Temperatures ◽  
Small Polaron ◽  
Complex Impedance ◽  
Bound Water ◽  
Data Representation ◽  
Industrial Applications ◽  
Mechanical And Thermal Properties ◽  
Wide Range ◽  
Complex Electrical Conductivity

The unique physicochemical, electrical, mechanical, and thermal properties of micas make them suitable for a wide range of industrial applications, and thus, the interest for these kind of hydrous aluminosilicate minerals is still persistent, not only from a practical but also from a scientific point of view. In the present work, complex impedance spectroscopy measurements were carried out in muscovite and biotite micas, perpendicular to their cleavage planes, over a broad range of frequencies (10−2 Hz to 106 Hz) and temperatures (473–1173 K) that have not been measured so far. Different formalisms of data representation were used, namely, Cole-Cole plots of complex impedance, complex electrical conductivity and electric modulus to analyze the electrical behavior of micas and the electrical signatures of the dehydration/dehydroxylation processes. Our results suggest that ac-conductivity is affected by the structural hydroxyls and the different concentrations of transition metals (Fe, Ti and Mg) in biotite and muscovite micas. The estimated activation energies, i.e., 0.33–0.83 eV for biotite and 0.69–1.92 eV for muscovite, were attributed to proton and small polaron conduction, due to the bound water and different oxidation states of Fe.

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