scholarly journals Rigid Polyurethane Foams with Various Isocyanate Indices Based on Polyols from Rapeseed Oil and Waste PET

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 738 ◽  
Author(s):  
Aiga Ivdre ◽  
Arnis Abolins ◽  
Irina Sevastyanova ◽  
Mikelis Kirpluks ◽  
Ugis Cabulis ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Rapeseed Oil ◽  
Crosslink Density ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Cell Content ◽  
Natural Sources ◽  
Isocyanate Index ◽  
Closed Cell

Developing polyols derived from natural sources and recycling materials attracts great interest for use in replacing petroleum-based polyols in polyurethane production. In this study, rigid polyurethane (PUR) foams with various isocyanate indices were obtained from polyols based on rapeseed oil and polyethylene terephthalate (RO/PET). The various properties of the prepared PUR foams were investigated, and the effect of the isocyanate index was evaluated. The closed-cell content and water absorption were not impacted by the change of the isocyanate index. The most significant effect of increasing the isocyanate index was on the dimensional stability of the resulting foams. This is due to the increased crosslink density, as evidenced by the increased formation of isocyanurate and increase of the glass transition temperature. Additionally, the influence on compression strength, modulus, and long-term thermal conductivity were evaluated and compared with reference PUR foams from commercially available polyols. Rigid PUR foams from RO/PET polyol were found to be competitive with reference materials and could be used as thermal insulation material.

The Synthesis and Application of a Novel Class of Polyols for Preparation of Polyurethane

2013 ◽  
Vol 357-360 ◽  
pp. 1441-1445
Author(s):  
Xiao Lin Li ◽  
Zheng Fang ◽  
Dong Ji ◽  
Zhi Dong Wan ◽  
Kai Guo
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Polyurethane Foams ◽  
Low Density ◽  
Cell Content ◽  
Low Thermal Conductivity ◽  
High Compressive Strength ◽  
Rigid Polyurethane Foams ◽  
Closed Cell ◽  
Rigid Foams

The synthesis of a novel class of diamine-based polyols derivatives and the potentials and the limitations of these polyols were reported. This class of diamine-based polyols with high hydroxyl values and no acid values can be used in rigid polyurethane foams. The prepared rigid foams show the properties of low density, high closed cell content, low thermal conductivity, and high compressive strength.

Three Different Approaches for Polyol Synthesis from Rapeseed Oil

2013 ◽  
Vol 559 ◽  
pp. 69-74 ◽  
Author(s):  
Mikelis Kirpluks ◽  
Ugis Cabulis ◽  
Maria Kurańska ◽  
Aleksander Prociak
Keyword(s):  
Rapeseed Oil ◽  
Average Molecular Weight ◽  
Acid Value ◽  
Polyurethane Foams ◽  
Polyol Synthesis ◽  
Scale Production ◽  
Insulation Material ◽  
Technological Parameters ◽  
Cell Content ◽  
Hydroxyl Value

Three different kinds of polyols from rapeseed oil were synthesised and characterized during this study. Afterwards, using these polyols rigid polyurethane foams were produced, which are used as thermal insulation material in construction industry and in production of refrigerators. Polyols from rapeseed oil were synthesised by epoxidation, transamidization and transesterification methods. One rapeseed oil based polyol was synthesized by partial epoxidation of the double bonds in fatty acid chains and overall opening oxirane rings by using diethylene glycol. Other two methods transamidization and transesterification of ester bonds of triglyceride were carried out using diethanolamine and triethanolamine respectively. To use these polyols for production of polyurethane foams, hydroxyl value, acid value, water content, viscosity and density of polyols were determinated. The functionality of obtained polyols was calculated on the base of number-average molecular weight and hydroxyl value. After laboratory trials a pilot scale production of the rapeseed oil polyols was carried out in 50 L reactor. From synthesized polyols rigid polyurethane foam samples were produced in laboratory scale and also in semi industrial scale, using industrial high pressure spraying equipment machine. Technological parameters, density and closed cell content were determined for obtained polyurethane foams.

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.

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

2021 ◽  
pp. 0021955X2110626
Author(s):  
Tae Seok Kim ◽  
Yeongbeom Lee ◽  
Chul Hyun Hwang ◽  
Kwang Ho Song ◽  
Woo Nyon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Cell Size ◽  
Thermal Insulation ◽  
Coefficient Of Thermal Expansion ◽  
Lower Surface ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Pu Foams

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.

Temperature dependency of the long-term thermal conductivity of spray polyurethane foam

2021 ◽  
pp. 174425912110454
Author(s):  
Neal Holcroft
Keyword(s):  
Thermal Conductivity ◽  
Polyurethane Foam ◽  
Cellular Structure ◽  
Gas Diffusion ◽  
Temperature Dependent ◽  
Blowing Agent ◽  
Closed Cell ◽  
Wall Assembly ◽  
Cell Foam

The thermal properties of closed-cell foam insulation display a more complex behaviour than other construction materials due to the properties of the blowing agent captured in their cellular structure. Over time, blowing agent diffuses out from and air into the cellular structure resulting in an increase in thermal conductivity, a process that is temperature dependent. Some blowing agents also condense at temperatures within the in-service range of the insulation, resulting in non-linear temperature dependent relationships. Moreover, diffusion of moisture into the cellular structure increases thermal conductivity. Standards exist to quantify the effect of gas diffusion on thermal conductivity, however only at standard laboratory conditions. In this paper a new test procedure is described that includes calculation methods to determine Temperature Dependent Long-Term Thermal Conductivity (LTTC(T)) functions for closed-cell foam insulation using as a test material, a Medium-Density Spray Polyurethane Foam (MDSPF). Tests results are provided to show the validity of the method and to investigate the effects of both conditioning and mean test temperature on change in thermal conductivity. In addition, testing was conducted to produce a moisture dependent thermal conductivity function. The resulting functions were used in hygrothermal simulations to assess the effect of foam aging, in-service temperature and moisture content on the performance of a typical wall assembly incorporating MDSPF located in four Canadian climate zones. Results show that after 1 year, mean thermal conductivity increased 15%–16% and after 5 years 23%–24%, depending on climate zone. Furthermore, the use of the LTTC(T) function to calculate the wall assembly U-value improved accuracy between 3% and 5%.

scholarly journals Physical Properties of Soy-Phosphate Polyol-Based Rigid Polyurethane Foams

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hongyu Fan ◽  
Ali Tekeei ◽  
Galen J. Suppes ◽  
Fu-Hung Hsieh
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Water Content ◽  
Polyurethane Foams ◽  
Solid Polymer ◽  
Mechanical And Thermal Properties ◽  
Blowing Agent ◽  
Isocyanate Index ◽  
Pu Foams

Water-blown rigid polyurethane (PU) foams were made from 0–50% soy-phosphate polyol (SPP) and 2–4% water as the blowing agent. The mechanical and thermal properties of these SPP-based PU foams (SPP PU foams) were investigated. SPP PU foams with higher water content had greater volume, lower density, and compressive strength. SPP PU foams with 3% water content and 20% SPP had the lowest thermal conductivity. The thermal conductivity of SPP PU foams decreased and then increased with increasing SPP percentage, resulting from the combined effects of thermal properties of the gas and solid polymer phases. Higher isocyanate density led to higher compressive strength. At the same isocyanate index, the compressive strength of some 20% SPP foams was close or similar to the control foams made from VORANOL 490.

scholarly journals A Pathway toward a New Era of Open-Cell Polyurethane Foams—Influence of Bio-Polyols Derived from Used Cooking Oil on Foams Properties

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5161
Author(s):  
Maria Kurańska ◽  
Elżbieta Malewska ◽  
Krzysztof Polaczek ◽  
Aleksander Prociak ◽  
Joanna Kubacka
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Foam Cell ◽  
Polyurethane Foams ◽  
Cell Content ◽  
Open Cell ◽  
New Era ◽  
Used Cooking Oil ◽  
Coefficient Of Thermal Conductivity ◽  
Cooking Oils

In order to create greener polyurethane (PUR) foams, modified used cooking oils (UCO) were applied as starting resources for the synthesis of bio-polyols. The bio-polyols were produced using transesterification of UCO with diethylene glycol (UCO_DEG) and triethanolamine (UCO_TEA). Next, open-cell PUR foams were synthesized by replacing 20, 40, 60, 80 and 100% of the petrochemical polyol with the bio-polyol UCO_DEG or UCO_TEA. It was observed that an increasing bio-polyol content (up to 60%) led to an increase of the closed cell content. However, a further increase in the bio-polyol content up to 100% resulted in foam cell opening. The bio-foams obtained in the experiment had an apparent density of 13–18 kg/m3. The coefficient of thermal conductivity was determined at three different average temperatures: 10, 0 and −10 °C. The PUR bio-foams modified with bio-polyol UCO_TEA had lower values of thermal conductivity, regardless of the average temperature (35.99–39.57 mW/m·K) than the foams modified with bio-polyol UCO_DEG (36.95–43.78 mW/m·K). The compressive strength of most of the bio-foams was characterized by a higher value than the compressive strength of the reference material (without bio-polyol). Finally, it was observed that the bio-materials exhibited dimensional stability at 70 °C.

scholarly journals Novel Biobased Polyol Using Corn Oil for Highly Flame-Retardant Polyurethane Foams

2019 ◽  
Vol 5 (1) ◽  
pp. 13 ◽  
Author(s):  
Sneha Ramanujam ◽  
Camila Zequine ◽  
Sanket Bhoyate ◽  
Brooks Neria ◽  
Pawan Kahol ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Corn Oil ◽  
Gel Permeation Chromatography ◽  
Polyurethane Foams ◽  
Cell Content ◽  
Ene Reaction ◽  
Closed Cell ◽  
Improved Stability ◽  
Flame Retardant Properties

A novel bio-based polyol was synthesized using corn oil and 2-mercaptoethanol via thiol-ene reaction as an alternative to petroleum-based polyol for the synthesis of polyurethane foams. The polyol was analyzed using wet chemical techniques to obtain hydroxyl number and viscosity. Infrared spectroscopy and gel permeation chromatography were used to confirm the structural properties of the foams. Flame-retardant polyurethane foams were prepared by the addition of different concentrations of dimethyl methyl phosphonate (DMMP) in final foam composition. The effect of DMMP on the thermo-mechanical properties of the polyurethane foams was analyzed. The TGA analysis showed improved stability of the final char with addition of DMMP in the foams. All the foams maintained a well-defined cellular structure and over 95% of closed cell content. The horizontal burning test showed reduced burning time and weight loss from 115 s and 38 wt.% for the neat foams, to 3.5 s and 5.5 wt.% for DMMP-containing foams (1.94 wt.% P). The combustion test using cone calorimeter showed a considerable reduction in heat release rate and total heat release. Thus, our study shows that corn-oil based polyol can be used to produce renewable polyol for industrially producible rigid polyurethane foams. The addition of a small amount of DMMP could result in a significant reduction in the flame-retardant properties of the polyurethane foams.

Preparation and performance of melamine-formaldehyde rigid foams with high closed cell content

2021 ◽  
pp. 026248932110171
Author(s):  
Chunhui Li ◽  
Haihong Ma ◽  
Congqiang Song ◽  
Zhengfa Zhou ◽  
Weibing Xu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Thermal Insulation ◽  
Apparent Density ◽  
Insulation Material ◽  
Melamine Formaldehyde ◽  
Cell Content ◽  
Closed Cell ◽  
Rigid Foams ◽  
Foaming Temperature

Melamine-formaldehyde (MF)rigid foams with high closed cell content were prepared via oven heating process, using MF prepolymer prepared from melamine and paraformaldehyde as a matrix, cyclohexane as the foaming agent, dimethyl silicon oil as the foam stabilizers, hydrochloric acid as the catalyst. The effect of MF prepolymer viscosity, foaming temperature, amount of catalyst on morphology, closed cell content, apparent density, water absorption and compressive strength of MF rigid foams were systematically studied. The optimized foaming conditions are as follows: the viscosity of MF prepolymer ranges from 35 Pa·s to 45 Pa·s, the foaming temperature is 125°C and the content of the catalyst is 0.65 wt%. The as-prepared MF foams showed the best comprehensive performance with closed cell content of 83.5%, apparent density of 62 kg·m−3, water absorption of 12.0%, compressive strength of 292kPa, thermal conductivity of 0.033 W m−1 K−1 and limiting oxygen index (LOI) of 36%. Compared to conventional organic foams, MF rigid foams possess low water absorption, excellent thermal insulation and flame retardancy due to high closed cell content, and can be expected to be used as thermal insulation material for building exterior walls.

Sign in / Sign up

Export Citation Format

Share Document