scholarly journals Lignin as a Partial Polyol Replacement in Polyurethane Flexible Foam

Molecules ◽  
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.

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.

Mechanical and thermal characterization of grafted PP-NCC nanocomposites

2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik
Keyword(s):  
Thermal Properties ◽  
Interfacial Adhesion ◽  
Thermal Characterization ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Twin Screw ◽  
Thermal Stability Of

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.

The influence of adding long basalt fiber on the mechanical and thermal properties of composites based on poly(oxymethylene)

2018 ◽  
Vol 33 (4) ◽  
pp. 435-450 ◽  
Author(s):  
Patrycja Bazan ◽  
Stanisław Kuciel ◽  
Mariola Sądej
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Average Length ◽  
Flexural Modulus ◽  
Basalt Fiber ◽  
Charpy Impact ◽  
Mechanical And Thermal Properties ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Atr Spectroscopy

The work has evaluated the possibility of the potential reinforcing of poly(oxymethylene) (POM) by basalt fibers (BFs) and influence of BFs addition on thermal properties. Two types of composites were produced by injection molding. There were 20 and 40 wt% long BFs content with an average length of 1 mm. The samples were made without using a compatibilizer. In the experimental part, the basic mechanical properties (tensile strength, modulus of elasticity, strain at break, flexural modulus, flexural strength, and deflection at 3.5% strain) of composites based on POM were determined. Tensile properties were also evaluated at three temperatures −20°C, 20°C, and 80°C. The density and Charpy impact of the produced composites were also examined. The influence of water absorption on mechanical properties was investigated. Thermal properties were conducted by the differential scanning calorimetry, thermal gravimetric analysis, and fourier transform infrared (FTIR)-attenuation total reflection (ATR) spectroscopy analysis. In order to make reference to the effects of reinforcement and determine the structure characteristics, scanning electron microscopy images were taken. The addition of 20 and 40 wt% by weight of fibers increases the strength and the stiffness of such composites by more than 30–70% in the range scale of temperature. Manufactured composites show higher thermal and dimensional stability in relation to neat POM.

scholarly journals Mechanical and Thermal Characterization of Natural Intralaminar Hybrid Composites Based on Sisal

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 866 ◽  
Author(s):  
Alexandre L. Pereira ◽  
Mariana D. Banea ◽  
Jorge S.S. Neto ◽  
Daniel K.K. Cavalcanti
Keyword(s):  
Thermal Properties ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Thermal Characterization ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
The Matrix ◽  
American Society ◽  
Curaua Fibers

The main objective of this work was to investigate the effect of hybridization on the mechanical and thermal properties of intralaminar natural fiber-reinforced hybrid composites based on sisal. Ramie, sisal and curauá fibers were selected as natural fiber reinforcements for the epoxy matrix based composites, which were produced by the hand lay-up technique. Tensile, flexural and impact tests were carried out according to American society for testing and materials (ASTM) standards to characterize the hybrid composites, while differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to evaluate the thermal properties. It was found that the mechanical properties are improved by hybridization of sisal based composites. The thermal analysis showed that the hybridization did not significantly affect the thermal stability of the composites. A scanning electron microscopy (SEM) was used to examine the fracture surface of the tested specimens. The SEM images showed a brittle fracture of the matrix and fiber breakage near the matrix.

scholarly journals Micro and nanocomposites of polybutadienebased polyurethane liners with mineral fillers and nanoclay: thermal and mechanical properties

2017 ◽  
Vol 15 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Pablo Ross ◽  
Germán Escobar ◽  
Guillermo Sevilla ◽  
Javier Quagliano
Keyword(s):  
Thermal Properties ◽  
Polymer Chains ◽  
Toluene Diisocyanate ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mineral Fillers

AbstractMicro and nanocomposites of hydroxyl terminated polybutadiene (HTPB)-based polyurethanes (NPU) were obtained using five mineral fillers and Cloisite 20A nanoclay, respectively. Samples were prepared by the reaction of HTPB polyol and toluene diisocyanate (TDI), and the chain was further extended with glyceryl monoricinoleate to produce the final elastomeric polyurethanes. Mechanical and thermal properties were studied, showing that mineral fillers (20%w/w) significantly increased tensile strength, in particular nanoclay (at 5% w/w). When nanoclay-polymer dispersion was modified with a silane and hydantoin-bond promoter, elongation at break was significantly increased with respect to NPU with C20A. Thermal properties measured by differential scanning calorimetry (DSC) were not significantly affected in any case. The molecular structure of prepared micro and nanocomposites was confirmed by Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Interaction of fillers with polymer chains is discussed, considering the role of silanes in compatibilization of hydrophilic mineral fillers and hydrophobic polymer. The functionalization of nanoclay with HMDS silane was confirmed using FTIR. Microstructure of NPU with C20A nanoclay was confirmed by Atomic Force Microscopy (AFM).

Purification and characterization of kraft lignin

Holzforschung ◽  
2015 ◽  
Vol 69 (8) ◽  
pp. 943-950 ◽  
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.

HIGH-IMPACT PP NANOCOMPOSITES: INFLUENCE OF CLAY CONTENT ON MECHANICAL AND THERMAL PROPERTIES

2013 ◽  
Vol 12 (06) ◽  
pp. 1350039
Author(s):  
L. G. FURLAN ◽  
RICARDO V. B. OLIVEIRA ◽  
ANDRÉIA C. E. MELLO ◽  
SUSANA A. LIBERMAN ◽  
MAURO A. S. OVIEDO ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Impact Strength ◽  
Flexural Modulus ◽  
Clay Content ◽  
Mechanical Analysis ◽  
High Impact ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Izod Impact

The preparation of high-impact polypropylene nanocomposites with different organo-montmorillonite (O-MMT) contents by means of meltprocessing was investigated. The nanocomposite properties were evaluated by transmission electron microscopy (TEM), flexural modulus, izod impact strength, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was noticed that the PP/O-MMT nanocomposites properties were affected by clay content. Exceptional improvements in impact strength were obtained (maximum of 185%) by the use of low O-MMT content. The results showed that higher enhancement on mechanical/thermal properties was obtained by 3 wt.% of O-MMT instead of higher quantities.

scholarly journals Physical Properties of Soy-Phosphate Polyol-Based Rigid Polyurethane Foams

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hongyu Fan ◽  
Ali Tekeei ◽  
Galen J. Suppes ◽  
Fu-Hung Hsieh
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Water Content ◽  
Polyurethane Foams ◽  
Solid Polymer ◽  
Mechanical And Thermal Properties ◽  
Blowing Agent ◽  
Isocyanate Index ◽  
Pu Foams

Water-blown rigid polyurethane (PU) foams were made from 0–50% soy-phosphate polyol (SPP) and 2–4% water as the blowing agent. The mechanical and thermal properties of these SPP-based PU foams (SPP PU foams) were investigated. SPP PU foams with higher water content had greater volume, lower density, and compressive strength. SPP PU foams with 3% water content and 20% SPP had the lowest thermal conductivity. The thermal conductivity of SPP PU foams decreased and then increased with increasing SPP percentage, resulting from the combined effects of thermal properties of the gas and solid polymer phases. Higher isocyanate density led to higher compressive strength. At the same isocyanate index, the compressive strength of some 20% SPP foams was close or similar to the control foams made from VORANOL 490.

scholarly journals Tough Materials Through Ionic Interactions

2021 ◽  
Vol 9 ◽  
Author(s):  
Linda Salminen ◽  
Erno Karjalainen ◽  
Vladimir Aseyev ◽  
Heikki Tenhu
Keyword(s):  
Thermal Properties ◽  
Ion Pairs ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Polymer Materials ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Shape Stability ◽  
Chemical Crosslinks ◽  
Unique Approach

This article introduces butyl acrylate-based materials that are toughened with dynamic crosslinkers. These dynamic crosslinkers are salts where both the anion and cation polymerize. The ion pairs between the polymerized anions and cations form dynamic crosslinks that break and reform under deformation. Chemical crosslinker was used to bring shape stability. The extent of dynamic and chemical crosslinking was related to the mechanical and thermal properties of the materials. Furthermore, the dependence of the material properties on different dynamic crosslinkers—tributyl-(4-vinylbenzyl)ammonium sulfopropyl acrylate (C4ASA) and trihexyl-(4-vinylbenzyl)ammonium sulfopropyl acrylate (C6ASA)—was studied. The materials’ mechanical and thermal properties were characterized by means of tensile tests, dynamic mechanical analysis, differential scanning calorimetry, and thermogravimetric analysis. The dynamic crosslinks strengthened the materials considerably. Chemical crosslinks decreased the elasticity of the materials but did not significantly affect their strength. Comparison of the two ionic crosslinkers revealed that changing the crosslinker from C4ASA to C6ASA results in more elastic, but slightly weaker materials. In conclusion, dynamic crosslinks provide substantial enhancement of mechanical properties of the materials. This is a unique approach that is utilizable for a wide variety of polymer materials.

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

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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