Hydraulic resistance of rigid polyurethane foams. I. Effect of different surfactants on foam structure and properties

2004 ◽  
Vol 93 (6) ◽  
pp. 2821-2829 ◽  
Author(s):  
Pravakar Mondal ◽  
D. V. Khakhar
Keyword(s):  
Hydraulic Resistance ◽  
Polyurethane Foams ◽  
Structure And Properties ◽  
Foam Structure ◽  
Rigid Polyurethane Foams

Cooperative effect of rapeseed oil-based polyol and egg shells on the structure and properties of rigid polyurethane foams

2020 ◽  
Vol 90 ◽  
pp. 106696 ◽  
Author(s):  
Milena Leszczyńska ◽  
Joanna Ryszkowska ◽  
Leonard Szczepkowski ◽  
Maria Kurańska ◽  
Aleksander Prociak ◽  
...  
Keyword(s):  
Rapeseed Oil ◽  
Cooperative Effect ◽  
Polyurethane Foams ◽  
Structure And Properties ◽  
Rigid Polyurethane Foams ◽  
Egg Shells

Rigid polyurethane foams modified with borate and oxamide groups – Preparation and properties

2020 ◽  
pp. 0021955X2094309
Author(s):  
Iwona Zarzyka ◽  
Tomasz Pacześniak ◽  
Wiesław Frącz
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Propylene Carbonate ◽  
Polyurethane Foams ◽  
Diphenylmethane Diisocyanate ◽  
Foam Structure ◽  
Rigid Polyurethane Foams ◽  
Dimension Stability ◽  
Insulating Properties ◽  
Good Heat

In this work the results of the research on modification of rigid polyurethane foams properties by new polyols with borate and oxamide groups have been presented. Propylene glycols — the products of hydroxyalkylation of N,N′-bis(2-hydroxypropyl)oxamide bis(dihydrogenborate) by excess of propylene carbonate (PC) was used as a polyol component. The new polyols have been foamed using polymeric 4,4′-diphenylmethane diisocyanate, water and triethylamine. The modification of the foam structure by oxamide and borate groups guarantees their low water uptake, very good heat-insulating properties, good dimension stability and decreases their flammability, and does not worsen their mechanical properties and thermal stability.

scholarly journals Fly Ash as an Eco-Friendly Filler for Rigid Polyurethane Foams Modification

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6604
Author(s):  
Monika Kuźnia ◽  
Anna Magiera ◽  
Beata Zygmunt-Kowalska ◽  
Katarzyna Kaczorek-Chrobak ◽  
Kinga Pielichowska ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Polyurethane Foams ◽  
Mechanical And Thermal Properties ◽  
Rigid Polyurethane Foam ◽  
Structure And Properties ◽  
Rigid Polyurethane Foams ◽  
Polyurethane Composites ◽  
Thermal Stability Of

There is currently a growing demand for more effective thermal insulation materials with the best performance properties. This research paper presents the investigation results on the influence of two types of filler on the structure and properties of rigid polyurethane foam composites. Fly ash as a product of coal combustion in power plants and microspheres of 5, 10, 15, and 20 wt.%, were used as rigid polyurethane foams modifiers. The results of thermal analysis, mechanical properties testing, and cellular structure investigation performed for polyurethane composites show that the addition of fly ash, up to 10 wt.%, significantly improved the majority of the tested parameters. The use of up to 20 wt.% of microspheres improves the mechanical and thermal properties and thermal stability of rigid polyurethane foams.

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.

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.

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