Experimental Study of Loaded Foams During Free Fall Investigation and Evaluation of Microstructure

2021 ◽  
Author(s):  
Noureddine BOUMDOUHA ◽  
Zitouni SAFIDINE ◽  
Achraf BOUDIAF
Keyword(s):  
Polyurethane Foam ◽  
Shock Absorber ◽  
Impact Test ◽  
Mechanical Characterization ◽  
Cell Structure ◽  
Free Fall ◽  
Polyurethane Foams ◽  
High Degree ◽  
Drop Impact Test ◽  
Cellular Polymer

Abstract We aim to maintain as much control as possible over the development of the microstructure during the manufacture of polyurethane foam with a certain density. As a result, the finished product may not contain the required characteristics for the shock absorber used. That is why polyurethane foam loaded with zinc oxide and silica must be able to sustain the cellular structure and strengthen it. Mechanical characterization was carried out utilizing a dynamic drop impact test conducted on locally developed and constructed equipment. Polyurethane foams' mechanical properties are highly reliant on their density, cell structure (size and shape), and the fraction of open or closed cells. Within the cell structure, the foam may be directed preferentially. Following that, Raman spectroscopy and SEM investigation were used to visualize the semi-opened cells of the cellular polymer. The cellular polymer appears to possess permanent, regular cellular structures with a high degree of reversibility in terms of overlap.

Polyol from spent coffee grounds: Performance in a model pour-in-place rigid polyurethane foam system

2020 ◽  
Vol 56 (6) ◽  
pp. 630-645 ◽  
Author(s):  
Ibrahim Sendijarevic ◽  
Karol W Pietrzyk ◽  
Christi M. Schiffman ◽  
Vahid Sendijarevic ◽  
Alper Kiziltas ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Raw Materials ◽  
Intact Cell ◽  
Cell Structure ◽  
Acid Value ◽  
Polyurethane Foams ◽  
Rigid Polyurethane Foam ◽  
Spent Coffee Grounds ◽  
Rigid Polyurethane Foams ◽  
Coffee Grounds

The objective of this study was to produce a polyol from spent coffee grounds via acid liquification process that meets performance requirements for use in polyurethane applications. The spent coffee grounds based polyol was characterized and evaluated on a fully catalyzed model rigid polyurethane foam system. The pH of the polyol was 6.8, acid value 4.12 mg KOH/g, and hydroxyl value 302.6 mg KOH/g, which are in the range of polyols used in rigid polyurethane foams. The reactivity study confirmed enhanced reactivity of the spent coffee grounds polyol compared to standard sucrose-glycerol initiated polyether polyols, which can be attributed to higher content of primary reactive hydroxyls. Scanning electron microscopy microphotographs of the foams prepared with 10%, 20%, and 30% spent coffee grounds polyol based on total polyols in the formulation revealed a drained dodecahedron type cell structure with intact cell windows as a clear indication of the closed cell structure typical for the rigid polyurethane foams used in thermal insulation applications. Results of this study confirmed the feasibility to produce polyols from spent coffee grounds with performance characteristics suitable for polyurethane application. The fact that spent coffee grounds are readily available industrial waste generated in instant coffee manufacturing, makes this biomass residue a sustainable source of raw materials for scalable production of polyols for polyurethanes.

A greener and sustainable approach for converting polyurethane foam rejects into superior polyurethane coatings

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mechanical Properties ◽  
Polyurethane Foam ◽  
Sebacic Acid ◽  
Polyurethane Foams ◽  
Hexamethylene Diisocyanate ◽  
Alkali Resistance ◽  
Microwave Reaction ◽  
P Recycling ◽  
Amine Groups ◽  
Green Polymer

Recycling is a crucial area of research in green polymer chemistry. Various developments in recycling are driven by Environmental concerns, interest in sustainability and desire to decrease the dependence on non-renewable petroleum based materials. Polyurethane foams [PUF] are widely used due to their light weight and superior heat insulation as well as good mechanical properties. As per survey carried Polyurethane Foam Association, 12 metric tonnes of polyurethane foam are discharged during manufacturing and/or processing and hence recycling of PUF is necessary for better economics and ecological reasons. In present study, rejects of PUF is subjected to reaction with a diethylene amine in presence of sodium hydroxide [NaOH] as catalyst, as a result depolymerised product containing hydroxyl and amine groups is obtained. Conventional and Microwave reaction for depolymerizing polyurethane foam have been carried, and best results are obtained by Microwave reaction. Further depolymerised product with hydroxyl and amine functionalities are reacted with bis (2-hydroxyethyl terephthalate) [BHET] obtained by recycling polyethylene terephthalate [PET] and sebacic acid, with stannous oxalate [FASCAT 2100 series] as catalyst to obtain Polyester amides. These Polyester amides having hydroxyl and amino groups in excess are cured with isocyanates-hexamethylene diisocyanate biuret [HDI biuret] and isophorone diisocyanate [IPDI] for coating applications. The coated films are characterized using physical, mechanical and chemical tests, which shows comparable physical, mechanical properties but alkali resistance is poor.

Preparation and Characterization of Soybean Oil-based Flame Retardant Rigid Polyurethane Foams Containing Phosphaphenanthrene Groups

2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang
Keyword(s):  
Soybean Oil ◽  
Flame Retardant ◽  
Chemical Structure ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Degradation Activation Energy ◽  
Ft Ir

A phosphaphenanthrene groups containing soybean oil based polyol (DSBP) was synthesized by epoxidized soybean oil (ESO) and 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Soybean oil based polyol (HSBP) was synthesized by ESO and H2O. The chemical structure of DSBP and HSBP were characterized with FT-IR and 1H NMR. The corresponding rigid polyurethane foams (RPUFs) were prepared by mixing DSBP with HSBP. The results revealed apparent density and compression strength of RPUFs decreased with increasing the DSBP content. The cell structure of RPUFs was examined by scanning electron microscope (SEM) which displayed the cells as spherical or polyhedral. The thermal degradation and flame retardancy of RPUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL 94 vertical burning test. The degradation activation energy (Ea) of first degradation stage reduced from 80.05 kJ/mol to 37.84 kJ/mol with 80 wt% DSBP. The RUPF with 80 wt% DSBP achieved UL94 V-0 rating and LOI 28.3. The results showed that the flame retardant effect was mainly in both gas phase and condensed phase.

Bio-based Polyurethane-clay Nanocomposite Foams: Systheses and Properties

2009 ◽  
Vol 1188 ◽  
Author(s):  
Min Liu ◽  
Zoran S. Petrovic ◽  
Yijin Xu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Mechanical And Thermal Properties ◽  
Cell Content ◽  
Modified Clay ◽  
Rigid Polyurethane Foams ◽  
Nanocomposite Foams ◽  
Organically Modified

AbstractStarting from a bio-based polyol through modification of soybean oil, BIOH™ X-210, two series of bio-based polyurethanes-clay nanocomposite foams have been prepared. The effects of organically-modified clay types and loadings on foam morphology, cell structure, and the mechanical and thermal properties of these bio-based polyurethanes-clay nanocomposite foams have been studied with optical microscopy, compression test, thermal conductivity, DMA and TGA characterization. Density of nanocomposite foams decreases with the increase of clay loadings, while reduced 10% compressive stress and yield stress keep constant up to 2.5% clay loading in polyol. The friability of rigid polyurethane-clay nanocomposite foams is high than that of foam without clay, and the friability for nanofoams from Cloisite® 10A is higher than that from 30B at the same clay loadings. The incorporation of clay nanoplatelets decreases the cell size in nanocomposite foams, meanwhile increases the cell density; which would be helpful in terms of improving thermal insulation properties. All the nanocomposite foams were characterized by increased closed cell content compared with the control foam from X-210 without clay, suggesting the potential to improve thermal insulation of rigid polyurethane foams by utilizing organically modified clay. Incorporation of clay into rigid polyurethane foams results in the increase in glass transition temperature: the Tg increased from 186 to 197 to 204 °C when 30B concentration in X-210 increased from 0 to 0.5 to 2.5%, respectively. Even though the thermal conductivity of nanocomposite foams from 30B is lower than or equal to that of rigid polyurethane control foam from X-210, thermal conductivity of nanocomposite foams from 10A is higher than that of control at all 10A concentrations. The reason for this abnormal phenomenon is not clear at this moment; investigation on this is on progress.

DEVELOPMENT AND RESEARCH OF POLYURETHANE FOAM COMPOSITE MATERIALS WITH LYSOZYME

2021 ◽  
Vol 43 (3) ◽  
pp. 204-213
Author(s):  
T.V. VISLOHUZOVA ◽  
◽  
R.A. ROZHNOVA ◽  
N.A. GALATENKO ◽  
◽  
...  
Keyword(s):  
Glass Transition ◽  
Composite Materials ◽  
Polyurethane Foam ◽  
Single Phase ◽  
Mechanical Tests ◽  
Polyurethane Foams ◽  
Scanning Calorimetry ◽  
Heating Capacity ◽  
Foam Composite ◽  
Treatment Of Wounds

The article is devoted to the development and research of the structure and properties of polyurethane foam (PUF) composite materials with the antibacterial enzyme lysozyme. A series of PUF composite materials with lysozyme of various concentrations (1, 3 and 5 wt %) were obtained. It is established that the immobilization of lysozyme occurs due to intermolecular hydrogen bonds by the method of IR spectroscopy. According to the results of physical-mechanical tests the adhesive strength of polyurethane foam compositions with lysozyme is in the range of 0,82–1,16 MPa. The introduction of lysozyme into the composition of polyurethane foams and an increase its amount causes a decrease in the values of adhesion strength by 18,1–29,3 %. According to differential scanning calorimetry the tested systems are single-phase with a glass transition temperature in the range of -49,20 to -49,86 °C. The introduction of lysozyme into the composition causes an increase heating capacity at the glass transition, which can be associated with a decrease of the packing density of macrochains resulting in an increase in free volume, which leads to an increase molecular mobility. According to the results of the analysis of transmission optical microscopy micrographs the studied PUF have a microporous structure, which depends on the content of filler in their composition. It was found that the presence of lysozyme in the composition of composite materials leads to a decrease in the percentage of porosity, an increase in the number of pores with a diameter of up to 300 μm, which is 76,7–82,4 % (while for PUF – 69,5 %) and the absence of pores with a diameter larger than 990 μm. Thermogravimetric characteristics indicate the heat resistance of the synthesized PUF to a temperature of 179,95 °C, which allows dry sterilization of samples without changing their characteristics. PUF composite materials with lysozyme are promising materials that can be used in medical practice as polymer compositions for the treatment of wounds and burns.

A Study of the Influence of Polymer and Cell Structure on Polyurethane Foam Properties for Better Riding Comfort

2020 ◽  
pp. 267-274
Author(s):  
Masahiro Isobe ◽  
Kazuto Usaka ◽  
Hiroyuki Utsumi ◽  
Kazuhiko Ohkubo
Keyword(s):  
Polyurethane Foam ◽  
Cell Structure ◽  
Foam Properties

scholarly journals Effective polyurethane compositions filled with industrial wastes

2018 ◽  
Vol 7 (2.13) ◽  
pp. 240
Author(s):  
Goncharova Margarita Alexandrovna ◽  
Korneeva Anastasia Olegovna ◽  
Korneev Oleg Olegovich ◽  
Hameed Ghalib Hussain Al-Surraiwy
Keyword(s):  
Polyurethane Foam ◽  
Residential Buildings ◽  
Converter Slag ◽  
Sandwich Panels ◽  
High Strength ◽  
Average Density ◽  
Polyurethane Foams ◽  
Industrial Wastes ◽  
Building Structures ◽  
Coefficient Of Thermal Conductivity

Formulations are developed and optimized for of rigid polyurethane foams filled with converter slag. The optimum content of the filler is 30%. Polyurethane compositions have the following characteristics: average density – 42.59 kg/m3, compressive strength at 10% deformation – 0.293 MPa, water absorption by volume 1.71%, coefficient of thermal conductivity – 0.028 W/m·0C. Polyurethane foams are applied in sandwich panels, multi-layer roof constructions and for the manufacture of fixing systems for metal rolled.Sandwich panels with polyurethane foam insulation and sheathing of specialized panels are designed for the construction of pre-fabricated residential buildings. The forecasting of polyurethane durability in building structures as thermal insulation in sandwich panels the foam lifespan is about 75 years, which is approximately two times greater than that of the unreinforced foam.Layered roof structures with modified rigid polyurethane foam are used for buildings and structures for various purposes. Their use makes it possible to solve several tasks: creating a complete architectural image, ensuring high strength and deformation characteristics with good noise and heat insulation, minimization when mounting. The use of lightweight, transportable and technologically advanced roofing elements in conditions of mass production creates significant opportunities for industrial construction. The proposed foam fixing systems during shipping rolled metal in containers makes it possible to exclude the possibility of the longitudinal and transverse shift of pallets with rolls, to protect metal from damage, to simplify the design of the foxing elements, reduce the production cost, and minimize the amount of time for fixing metal rolls in the container.  

Failure of Polyurethane Foams under Different Loading Conditions

2008 ◽  
Vol 385-387 ◽  
pp. 205-208 ◽  
Author(s):  
Liviu Marsavina ◽  
Tomasz Sadowski ◽  
Dan Mihai Constantinescu ◽  
Radu Negru
Keyword(s):  
Mechanical Properties ◽  
Polyurethane Foam ◽  
Polyurethane Foams ◽  
Experimental Results ◽  
Loading Conditions ◽  
Sandwich Composites ◽  
Considerable Influence ◽  
Three Point Bending

Polyurethane foam materials are widely used as cores in sandwich composites, for packing and cushioning. This paper presents the experimental results obtained for the mechanical properties of polyurethane foams in different loading conditions and the influence of impregnation on the mechanical properties. A 200 kg/m3 density polyurethane foam was tested in tension, compression and three point bending. The experimental results show that the impregnation layer has no effect on the strength of the foam, but has considerable influence on the tensile and flexure modulus.

Laboratory plant for evaluation of burnout rate of various materials

2021 ◽  
pp. 19-23
Author(s):  
Н.П. Копылов ◽  
Е.Ю. Сушкина ◽  
В.И. Новикова ◽  
В.В. Яшин
Keyword(s):  
Induction Period ◽  
Flame Retardant ◽  
Polyurethane Foam ◽  
Beech Wood ◽  
Polyurethane Foams ◽  
Air Flow Rate ◽  
Linear Section ◽  
Significant Discrepancy ◽  
Burnout Rate ◽  
Burn Rate

Описана методика исследования скорости выгорания различных материалов. Для реализации методики создана лабораторная установка. Экспериментально установлено, что процесс выгорания материалов зависит от температуры реактора и скорости воздушного потока. Кривая выгорания имеет S-образный вид и три характерных участка: индукционный период, линейный участок и участок реакции, где происходит выгорание углеродистого остатка. В табличной форме представлены результаты исследования некоторых широко распространенных материалов. The article describes a method for studying the burnout rate of various materials. There was created the laboratory plant for implementation of the method. It is experimentally established that the process of burnout of materials depends on the temperature of the reactor and the air flow rate. The burn-up curve has an S-shape and three characteristic sections: the induction period, the linear section, and the reaction section where the carbon residue burns out. The article presents the results of study of some widely distributed materials in tabular form. The mass burn rate of beech wood is 1.5 times higher than that one of pine. Perhaps this is due to the impregnation of beech with furniture varnish, since the sample was part of the furniture lining. It is noteworthy that significant discrepancy in the burn-up rates was obtained during combustion of samples of different brands of polyurethane foams. So, for hard polyurethane foam - “izolan 2”, which has a flame retardant in its composition, burnout curves with longer induction period are obtained (as a result of flame retardant action). However, the burnout rate is higher in comparison with soft polyurethane foam without flame retardant (foam rubber). The composition of the material “isolan-2”. Rubber also has a long induction period, but a high burnout rate.

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