scholarly journals A comparison of a novel formulation of rigid polyurethane foams synthesis by hydrocarbon blowing agents

2021 ◽  
Author(s):  
Zahir Bakiri
Keyword(s):  
Thermal Resistance ◽  
Thermal Insulation ◽  
Experimental Approach ◽  
Polyurethane Foams ◽  
Excellent Performance ◽  
Simple Formulation ◽  
Rigid Polyurethane Foams ◽  
Long Term Stability ◽  
Blowing Agents

Abstract A simple formulation of rigid polyurethane foams (RPUFs) is presented for obtaining a material, with good thermal insulation and long-term stability, based on the different hydrocarbon blowing agents (HBAs). The obtained formulation is prepared from isocyanate and polyol for construction application or appliances. A method and a particular experimental approach have realized to replace hazardous blowing agents (chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs)) with other less harmful agents to improve the thermal resistance of this polymer. The obtained results are very encouraging in certain foams prepared from HBA and provide excellent performance.

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 Rigid Polyurethane Foams Modified with Biochar

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5616
Author(s):  
Katarzyna Uram ◽  
Maria Kurańska ◽  
Jacek Andrzejewski ◽  
Aleksander Prociak
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Thermal Insulation ◽  
Foam Cells ◽  
Polyurethane Foams ◽  
Cross Sectional ◽  
Rigid Polyurethane Foams ◽  
Insulation Materials

This paper presents results of research on the preparation of biochar-modified rigid polyurethane foams that could be successfully used as thermal insulation materials. The biochar was introduced into polyurethane systems in an amount of up to 20 wt.%. As a result, foam cells became elongated in the direction of foam growth and their cross-sectional areas decreased. The filler-containing systems exhibited a reduction in their apparent densities of up to 20% compared to the unfilled system while maintaining a thermal conductivity of 25 mW/m·K. Biochar in rigid polyurethane foams improved their dimensional and thermal stability.

Rigid polyurethane foams moulded with new generation blowing agents

Polimery ◽  
2003 ◽  
Vol 48 (07/08) ◽  
pp. 565-567
Author(s):  
ALEKSANDER PROCIAK ◽  
MARCIN FIGURA
Keyword(s):  
Polyurethane Foams ◽  
Rigid Polyurethane Foams ◽  
Blowing Agents ◽  
New Generation

Limiting Current Oxygen Sensors with LSM as Dense Diffusion Barrier

2008 ◽  
Vol 368-372 ◽  
pp. 263-264
Author(s):  
Yin Lin Wu ◽  
Ling Wang ◽  
Fu Shen Li ◽  
Yan Qin Zhao
Keyword(s):  
Diffusion Barrier ◽  
Solid Electrolytes ◽  
Oxygen Sensor ◽  
Low Cost ◽  
Limiting Current ◽  
Excellent Performance ◽  
Long Term Stability ◽  
Oxygen Ion ◽  
Ion Conducting

A thick film type of limiting current oxygen sensor which uses yttria (8% mol) stabilized zirconia (YSZ) as oxygen ion conducting solid electrolytes and dense La0.8Sr0.2MnO3 (LSM) as diffusion barrier was developed successfully. The oxygen sensor showed excellent performance at oxygen concentrations ranging from 0 to 10 ppm. The advantages of the sensor are simple construction, low cost and potential long term stability.

Inherently flame-retardant rigid polyurethane foams with excellent thermal insulation and mechanical properties

Polymer ◽  
2018 ◽  
Vol 153 ◽  
pp. 616-625 ◽  
Author(s):  
Shui-Xiu Wang ◽  
Hai-Bo Zhao ◽  
Wen-Hui Rao ◽  
Sheng-Chao Huang ◽  
Ting Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Polyurethane Foams ◽  
Rigid Polyurethane Foams

The influence of blowing agents type on foaming process and properties of rigid polyurethane foams

Polimery ◽  
2018 ◽  
Vol 63 (10) ◽  
pp. 672-678 ◽  
Author(s):  
Maria Kuranska ◽  
Aleksander Prociak ◽  
Slawomir Michalowski ◽  
Karolina Zawadzinska
Keyword(s):  
Polyurethane Foams ◽  
Rigid Polyurethane Foams ◽  
Blowing Agents ◽  
Foaming Process
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