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

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.

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Mechanical and thermal characterization of tungsten particulate reinforced epoxy polymer composites

Journal of Engineering Research ◽

10.36909/jer.icmmm.12389 ◽

2021 ◽

Author(s):

Jenson Joseph. E ◽

◽

Kiran A.K ◽

Panneerselvam K ◽

◽

...

Keyword(s):

Flexural Strength ◽

Polymer Matrix ◽

Polymer Matrix Composites ◽

Thermal Characterization ◽

Industrial Applications ◽

Tungsten Particle ◽

Mechanical And Thermal Properties ◽

Matrix Composites ◽

Scanning Calorimetry ◽

Wide Range

Polymer matrix composites find a wide range of industrial applications due to its unique properties like lightweight, improved strength and the properties could also be tailored to suit specific applications. In this present work, a new class of polymer matrix composites with epoxy resin as matrix and tungsten metal particles as fillers were developed. The influence of the addition of tungsten fillers on mechanical and thermal properties of the composites has been investigated. The composites are fabricated by hand lay-up method and the specimens containing tungsten particle content by 1%, 3%, 5%, 7% and 9% by weight were developed. The developed specimens were subjected to mechanical and thermal investigations. Mechanical behavior was analyzed by conducting a flexural test and hardness as per ASTM standards. Thermal behavior was analyzed by conducting Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) of the developed composites. The results show that the addition of 7 wt. % filler has a higher value of flexural strength and hardness. Further addition of particulate fillers deteriorates the flexural strength and hardness due to agglomeration of filler content in the epoxy. Analysis by TGA and DSC shows that the thermal stability of composites is improved by increasing the addition of tungsten content in the epox.

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Lignin as a Partial Polyol Replacement in Polyurethane Flexible Foam

Molecules ◽

10.3390/molecules26082302 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2302

Author(s):

Akash Gondaliya ◽

Mojgan Nejad

Keyword(s):

Thermal Properties ◽

Gel Permeation Chromatography ◽

31P Nmr Spectroscopy ◽

Mechanical And Thermal Properties ◽

Scanning Calorimetry ◽

Hydroxyl Content ◽

Wide Range ◽

Foam Properties ◽

High Flexibility ◽

Pu Foams

This study was focused on evaluating the suitability of a wide range of lignins, a natural polymer isolated from different plant sources and chemical extractions, in replacing 20 wt.% of petroleum-based polyol in the formulation of PU flexible foams. The main goal was to investigate the effect of unmodified lignin incorporation on the foam’s structural, mechanical, and thermal properties. The hydroxyl contents of the commercial lignins were measured using phosphorus nuclear magnetic resonance (31P NMR) spectroscopy, molar mass distributions with gel permeation chromatography (GPC), and thermal properties with differential scanning calorimetry (DSC) techniques. The results showed that incorporating 20 wt.% lignin increased tensile, compression, tear propagation strengths, thermal stability, and the support factor of the developed PU flexible foams. Additionally, statistical analysis of the results showed that foam properties such as density and compression force deflection were positively correlated with lignin’s total hydroxyl content. Studying correlations between lignin properties and the performance of the developed lignin-based PU foams showed that lignins with low hydroxyl content, high flexibility (low Tg), and high solubility in the co-polyol are better candidates for partially substituting petroleum-based polyols in the formulation of flexible PU foams intended for the automotive applications.

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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 ◽

10.3390/polym13071058 ◽

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.

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Purification and characterization of kraft lignin

Holzforschung ◽

10.1515/hf-2014-0200 ◽

2015 ◽

Vol 69 (8) ◽

pp. 943-950 ◽

Cited By ~ 5

Author(s):

Wenwen Fang ◽

Marina Alekhina ◽

Olga Ershova ◽

Sami Heikkinen ◽

Herbert Sixta

Keyword(s):

Thermal Properties ◽

High Performance ◽

Inorganic Compounds ◽

Gel Permeation Chromatography ◽

Kraft Lignin ◽

Hot Water ◽

Scanning Calorimetry ◽

Target Values ◽

Lower Glass Transition Temperature

Abstract To upgrade the utilization of kraft lignin (KL) for high-performance lignin-based materials (e.g., carbon fiber), the purity, molecular mass distribution (MMD), and thermal properties need to be improved and adjusted to target values. Therefore, different methods, such as ultrasonic extraction (UE), solvent extraction, dialysis, and hot water treatment (HWT), were applied for the purification of KL. The chemical and thermal properties of purified lignin have been characterized by nuclear magnetic resonance, Fourier transform infrared, gel permeation chromatography, elemental analysis, differential scanning calorimetry, and thermogravimetric analysis. The lignin fractions obtained by UE with ethanol/acetone (E/A) mixture (9:1) revealed a very narrow MMD and were nearly free of inorganic compounds and carbohydrates. Further, the E/A-extracted lignin showed a lower glass transition temperature (Tg) and a clearly detectable melting temperature (Tm). Dialysis followed by HWT at 220°C is an efficient method for the removal of inorganics and carbohydrates; however, lignin was partly forming condensed structures during the treatment.

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Extraction, Characterization and Application of Cashew Nut Shell Liquid from Cashew Nut Shells

Chemical Science International Journal ◽

10.9734/csji/2019/v28i330143 ◽

2019 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Sampson Kofi Kyei ◽

Onyewuchi Akaranta ◽

Godfred Darko ◽

Uche J. Chukwu

Keyword(s):

Chemical Characterization ◽

Value Added ◽

Industrial Applications ◽

Physical Analysis ◽

Cashew Nut Shell Liquid ◽

Liquid Resin ◽

Practical Applications ◽

Cashew Nut ◽

Wide Range ◽

Cashew Nut Shell

In this study, cashew nut shell liquid has been extracted from cashew nut shells using an accelerated solvent extraction technique and was employed as a precursor for the synthesis of cashew nut shell liquid resin. The extract was a dark brown viscous liquid with an average yield of 30.61±0.200%. Results of the physical analysis showed a moisture content of 4.45±0.020% and a density of 0.95±0.300 gcm-3. The percentage brix and refractive index were 76.20±0.001 and 1.47 ±0.010 respectively. Chemical characterization showed a pH of 5.65±0.003; acid value of 8.25± 0.200 mg KOH/g; ash content of 1.80±0.6%; free fatty acid of 4.12±0.400 mg KOH/g; ester value of 247.01±0.100 mg KOH/g and a saponification value of 255.26±0.800 mg KOH/g. The FTIR spectra revealed that cashew nut shell liquid is polymeric. These findings confirm that higher phenolic compounds which can be used as potential precursors in industrial applications could be obtained from agro wastes. Practical Applications: Cashew nut shell liquid, an extract from cashew nut shell, an agro waste has a wide range of functional products. A practical application is synthesis of a high viscous, flexible cashew nut shell liquid resin with physical properties that are consistent with literature and could also be further used in other industrial applications. Further processing of cashew nut shell for the development of value added products like resin can be a better option.

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First, Do Not Degrade - an Alternative View on Polymer Laser Sintering

10.26434/chemrxiv.14754216 ◽

2021 ◽

Author(s):

Arkadiusz Antończak ◽

Mateusz Wieczorek ◽

Paulina Dzienny ◽

Bartłomiej Kryszak ◽

Anna Krokos ◽

...

Keyword(s):

Gel Permeation Chromatography ◽

Laser Sintering ◽

Polymer Materials ◽

Alternative View ◽

Scanning Calorimetry ◽

Entire Volume ◽

Beam Laser ◽

Dual Beam ◽

Wide Range ◽

First Time

<p>In the work, for the first time, the method of Dual Beam Laser Sintering of polymers (DBLS) was presented, in which, instead of heating the entire volume of the polymer throughout the entire process, a second, additional laser was used for selective in terms of volume and time heating of the material. The principle of operation and the design of the prototype are presented. Using the developed station, an experiment was carried out for sintering samples from technical polylactide powder as a function of selected process parameters. It confirmed the functionality of the method and proved that the sintering process can be controlled in a fairly wide range for the proposed method. A preliminary comparison of changes in the physicochemical properties of the obtained samples in relation to the samples sintered by standard laser sintering was carried out using Gel Permeation Chromatography, Fourier Transform Infrared Reflectance and Differential Scanning Calorimetry. The experiment showed that the presented method has the potential to limit the thermal degradation of sensitive polymer materials.</p>

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Bio-based polyhydroxyalkanoates blends and composites

Physical Sciences Reviews ◽

10.1515/psr-2020-0073 ◽

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.

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

Materials ◽

10.3390/ma13163513 ◽

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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Mechanical and Thermal Analyses of Metal-PLA Components Fabricated by Metal Material Extrusion

Inventions ◽

10.3390/inventions5030044 ◽

2020 ◽

Vol 5 (3) ◽

pp. 44 ◽

Cited By ~ 1

Author(s):

Mahdi Mohammadizadeh ◽

Hao Lu ◽

Ismail Fidan ◽

Khalid Tantawi ◽

Ankit Gupta ◽

...

Keyword(s):

Additive Manufacturing ◽

Thermal Analyses ◽

Microstructural Analysis ◽

Industrial Applications ◽

Mechanical And Thermal Properties ◽

Aluminum Powders ◽

Material Extrusion ◽

Metal Material ◽

Wide Range ◽

Metallic Parts

Metal additive manufacturing (AM) has gained much attention in recent years due to its advantages including geometric freedom and design complexity, appropriate for a wide range of potential industrial applications. However, conventional metal AM methods have high-cost barriers due to the initial cost of the capital equipment, support, and maintenance, etc. This study presents a low-cost metal material extrusion technology as a prospective alternative to the production of metallic parts in additive manufacturing. The filaments used consist of copper, bronze, stainless steel, high carbon iron, and aluminum powders in a polylactic acid matrix. Using the proposed fabrication technology, test specimens were built by extruding metal/polymer composite filaments, which were then sintered in an open-air furnace to produce solid metallic parts. In this research, the mechanical and thermal properties of the built parts are examined using tensile tests, thermogravimetric, thermomechanical and microstructural analysis.

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Value-Added Use of Invasive Plant-Derived Fibers as PHBV Fillers for Biocomposite Development

Polymers ◽

10.3390/polym13121975 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1975

Author(s):

Xiaoying Zhao ◽

Tolulope Lawal ◽

Mariane M. Rodrigues ◽

Talen Geib ◽

Yael Vodovotz

Keyword(s):

Thermal Stability ◽

Invasive Plants ◽

Invasive Plant ◽

Alkali Treatment ◽

Value Added ◽

Industrial Applications ◽

Lonicera Japonica ◽

Mechanical And Thermal Properties ◽

Interfacial Bond ◽

Lignocellulosic Fibers

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising biobased, biodegradable thermoplastic with limited industrial applications due to its brittleness and high cost. To improve these properties, lignocellulosic fibers from two invasive plants (Phalaris arundinacea and Lonicera japonica) were used as PHBV reinforcing agents. Alkali treatment of the fibers improved the PHBV–fiber interfacial bond by up to 300%. The morphological, mechanical, and thermal properties of the treated fibers were characterized, as well as their size, loading, and type, to understand their impact on performance of the biocomposites. The new biocomposites had improved thermal stability, restricted crystallization, reduced rigidity, and reduced cost compared with PHBV. Additionally, these novel biocomposites performed similarly to conventional plastics such as polypropylene, suggesting their potential as bio-alternatives for industrial applications such as semirigid packaging and lightweight auto body panels.

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