Effect of the geometry of fillers on the cell structure and performance of rigid polyurethane foams Wpływ geometrii napełniacza na strukturę komórkową i wybrane właściwości użytkowe sztywnych pianek poliuretanowych

2016 ◽  
Vol 1 (10) ◽  
pp. 171-175
Author(s):  
Maria Kurańska
Keyword(s):  
Cell Structure ◽  
Polyurethane Foams ◽  
Rigid Polyurethane Foams ◽  
And Performance

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.

scholarly journals Bio-Based Rigid Polyurethane Foams Modified with Phosphorus Flame Retardants

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 102
Author(s):  
Marcin Zemła ◽  
Aleksander Prociak ◽  
Sławomir Michałowski
Keyword(s):  
Rapeseed Oil ◽  
Flame Retardants ◽  
Thermal Conductivity Coefficient ◽  
Oxygen Index ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Triethyl Phosphate ◽  
Rigid Polyurethane Foams ◽  
Foaming Process ◽  
Cone Calorimeter Test

Rigid polyurethane foams (RPURF) containing a bio-polyol from rapeseed oil and different phosphorus-based flame retardants were obtained. Triethyl phosphate (TEP), dimethyl propane phosphonate (DMPP) and cyclic phosphonates Addforce CT 901 (20 parts per hundred polyol by weight) were used in the synthesis of RPURF. The influence of used flame retardants on foaming process, cell structure, and physical–mechanical properties as well as flammability of RPURF were examined. The addition of flame retardants influenced the parameters of the cellular structure and decreased compressive strength. All obtained foam materials had a low thermal conductivity coefficient, which allows them to be used as thermal insulation. The research results of bio-based RPURF were compared with foams obtained without bio-polyol. All modified materials had an oxygen index above 21 vol%; therefore, they can be classified as self-extinguishing materials. The analysis of parameters obtained after the cone calorimeter test showed that the modified RPURF have a lower tendency to fire development compared to the reference foams, which was particularly noticeable for the materials with the addition of DMPP.

scholarly journals Modification of Rigid Polyurethane Foams with the Addition of Nano-SiO2 or Lignocellulosic Biomass

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 107 ◽  
Author(s):  
Qinqin Zhang ◽  
Xiaoqi Lin ◽  
Weisheng Chen ◽  
Heng Zhang ◽  
Dezhi Han
Keyword(s):  
Cell Structure ◽  
Chemical Characterization ◽  
Polyurethane Foams ◽  
Peanut Shell ◽  
Step Method ◽  
Residual Content ◽  
Nano Sio2 ◽  
Rigid Polyurethane Foams ◽  
Building Insulation ◽  
Composite Foams

Many achievements have been made on the research of composite polyurethane foams to improve their structure and mechanical properties, and the composite foams have been widely utilized in building insulation and furniture. In this work, rigid polyurethane foams (RPUFs) with the addition of different fillers (nano-SiO2, peanut shell, pine bark) were prepared through the one-step method. The effects of inorganic nano-SiO2 and organic biomass on foam properties were evaluated by means of physical and chemical characterization. The characterization results indicate that the compressive strength values of prepared foams could fully meet the specification requirement for the building insulation materials. The inorganic and organic fillers have no effect on the hydrogen bonding states in composite RPUFs. Furthermore, compared to the biomass fillers, the addition of nano-SiO2 greatly influenced the final residual content of the fabricated foam. All composite foams exhibit closed-cell structure with smaller cell size in comparison with the parent foam. The prepared composite foams have the potential for utilization in building insulation.

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.

scholarly journals Vegetable Fillers and Rapeseed Oil-Based Polyol as Natural Raw Materials for the Production of Rigid Polyurethane Foams

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1772
Author(s):  
Milena Leszczyńska ◽  
Elżbieta Malewska ◽  
Joanna Ryszkowska ◽  
Maria Kurańska ◽  
Michał Gloc ◽  
...  
Keyword(s):  
Rapeseed Oil ◽  
Raw Materials ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Maximum Temperature ◽  
Renewable Raw Materials ◽  
The Sustainable Development ◽  
Rigid Polyurethane Foams ◽  
Foaming Process ◽  
Reported Study

The reported study concerns the introduction of renewable raw materials into the formulation of rigid polyurethane foams in the quest for the sustainable development of polymer composites. In this study, rigid polyurethane foam composites were prepared using 75 wt.% of rapeseed oil-based polyol and 15 parts per hundred parts of polyol (php) of natural fillers such as chokeberry pomace, raspberry seeds, as well as hazelnut and walnut shells. The influence of the used raw materials on the foaming process, structure, and properties of foams was investigated using a FOAMAT analyzer and a wide selection of characterization techniques. The introduction of renewable raw materials limited reactivity of the system, which reduced maximum temperature of the foaming process. Moreover, foams prepared using renewable raw materials were characterized by a more regular cell structure, a higher share of closed cells, lower apparent density, lower compressive strength and glass transition temperature, low friability (<2%), low water absorption (<1%), high dimensional stability (<±0.5%) and increased thermal stability. The proper selection and preparation of the renewable raw materials and the rational development of the polyurethane recipe composition allow for the preparation of environmentally-friendly foam products with beneficial application properties considering the demands of the circular economy in the synthesis of rigid foams.

Improvement of thermal conductivity of rigid polyurethane foams with aluminum nitride filler

2021 ◽  
pp. 026248932198897
Author(s):  
Serife Akkoyun ◽  
Meral Akkoyun
Keyword(s):  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Polyurethane Foams ◽  
Thermal Transitions ◽  
Rigid Polyurethane Foams ◽  
Noticeable Increase ◽  
Polyurethane Composite ◽  
Composite Foams ◽  
Step Procedure ◽  
Electrical Conductivities

The aim of this work is the fabrication of electrically insulating composite rigid polyurethane foams with improved thermal conductivity. Therefore, this study is focused on the effect of aluminum nitride (AlN) on the thermal and electrical conductivities of rigid polyurethane foams. For this purpose, aluminum nitride/rigid polyurethane composite foams were prepared using a three-step procedure. The electrical and thermal conductivities of the foams were characterized. The thermal transitions, mechanical properties and morphology of the foams were also examined. The results reveal that AlN induces an increase of the thermal conductivity of rigid polyurethane foam of 24% which seems to be a relatively noticeable increase in polymeric foams. The low electrical conductivity of the foams is preserved.

Morphology and Mechanical Properties of Nylon-1010-filled Rigid Polyurethane Foams

2004 ◽  
Vol 36 (4) ◽  
pp. 333-349 ◽  
Author(s):  
Bo Yin ◽  
Zhong-Ming Li ◽  
Hui Quan ◽  
Ming-Bo Yang ◽  
Qiu-Ming Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polyurethane Foams ◽  
Rigid Polyurethane Foams ◽  
Nylon 1010 ◽  
Morphology And Mechanical Properties
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