Hydraulic resistance of rigid polyurethane foams. II. Effect of variation of surfactant, water, and nucleating agent concentrations on foam structure and properties

2004 ◽  
Vol 93 (6) ◽  
pp. 2830-2837 ◽  
Author(s):  
Pravakar Mondal ◽  
D. V. Khakhar
2020 ◽  
Vol 90 ◽  
pp. 106696 ◽  
Author(s):  
Milena Leszczyńska ◽  
Joanna Ryszkowska ◽  
Leonard Szczepkowski ◽  
Maria Kurańska ◽  
Aleksander Prociak ◽  
...  

2020 ◽  
pp. 0021955X2094309
Author(s):  
Iwona Zarzyka ◽  
Tomasz Pacześniak ◽  
Wiesław Frącz

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.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6604
Author(s):  
Monika Kuźnia ◽  
Anna Magiera ◽  
Beata Zygmunt-Kowalska ◽  
Katarzyna Kaczorek-Chrobak ◽  
Kinga Pielichowska ◽  
...  

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.


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