scholarly journals New Flame Retardant Systems Based on Expanded Graphite for Rigid Polyurethane Foams

2020 ◽  
Vol 10 (17) ◽  
pp. 5817 ◽  
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Piotr Konca ◽  
Krzysztof Strzelec
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Flame Retardant ◽  
Construction Materials ◽  
Great Influence ◽  
Expanded Graphite ◽  
Polyurethane Foams ◽  
Bending Test ◽  
Maximum Temperature ◽  
Rigid Polyurethane Foams

The effect of the addition of new flame retardant systems on the properties of rigid polyurethane (RPUF) foams, in particular, reduction in flammability, was investigated. The modification included the introduction of a flame retardant system containing five parts by weight of expanded graphite (EG) (based on the total weight of polyol), one part by weight of pyrogenic silica (SiO2) and an ionic liquid (IL): 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim] [BF4]), in an amount of 3:1 with respect to the weight of added silica. The kinetics of the synthesis of modified foams—including the growth rate and the maximum temperature—were determined and the physicochemical properties, such as the determination of apparent density and structure by optical microscopy, mechanical properties such as impact strength, compressive strength and, three-point bending test were determined. An important aspect was also to examine the thermal properties such as thermal stability or flammability. It has been shown that for rigid polyurethane foams, the addition of expanded graphite in the presence of silica and ionic liquid has a great influence on the general use properties. All composites were characterized by reduced flammability as well as better mechanical properties, which may contribute to a wider use of rigid polyurethane foams as construction materials.

scholarly journals Composites of Rigid Polyurethane Foams Reinforced with POSS

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 336 ◽  
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Krzysztof Strzelec ◽  
Agnieszka Adamus-Włodarczyk ◽  
Agnė Kairytė ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Water Absorption ◽  
Viscoelastic Behavior ◽  
Physical And Mechanical Properties ◽  
Polyurethane Foams ◽  
Bending Test ◽  
Mechanical And Thermal Properties ◽  
Rigid Polyurethane Foams ◽  
Cell Shapes

Rigid polyurethane foams (RPUFs) were successfully modified with different weight ratios (0.5 wt%, 1.5 wt% and 5 wt%) of APIB-POSS and AEAPIB-POSS. The resulting foams were evaluated by their processing parameters, morphology (Scanning Electron Microscopy analysis, SEM), mechanical properties (compressive test, three-point bending test and impact strength), viscoelastic behavior (Dynamic Mechanical Analysis, DMA), thermal properties (Thermogravimetric Analysis, TGA, and thermal conductivity) and application properties (contact angle, water absorption and dimensional analysis). The results showed that the morphology of modified foams is significantly affected by the type of the filler and filler content, which resulted in inhomogeneous, irregular, large cell shapes and further affected the physical and mechanical properties of resulting materials. RPUFs modified with APIB-POSS represent better mechanical and thermal properties compared to the RPUFs modified with AEAPIB-POSS. The results showed that the best results were obtained for RPUFs modified with 0.5 wt% of APIB-POSS. For example, in comparison with unfilled foam, compositions modified with 0.5 wt% of APIB-POSS provide greater compression strength, better flexural strength and lower water absorption.

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

scholarly journals POSS Compounds as Modifiers for Rigid Polyurethane Foams (Composites)

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1092 ◽  
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Krzysztof Strzelec
Keyword(s):  
Mechanical Properties ◽  
Viscoelastic Behavior ◽  
Physical And Mechanical Properties ◽  
Large Cell ◽  
Processing Parameters ◽  
Polyurethane Foams ◽  
Bending Test ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Rigid Polyurethane Foams ◽  
Cell Shapes

Three types of polyhedral oligomeric silsesquioxanes (POSSs) with different functional active groups were used to modify rigid polyurethane foams (RPUFs). Aminopropylisobutyl-POSS (AP-POSS), trisilanoisobutyl-POSS (TS-POSS) and octa(3-hydroxy-3-methylbutyldimethylsiloxy-POSS (OH-POSS) were added in an amount of 0.5 wt.% of the polyol weight. The characteristics of fillers including the size of particles, evaluation of the dispersion of particles and their effect on the viscosity of the polyol premixes were performed. Next, the obtained foams were evaluated by their processing parameters, morphology (Scanning Electron Microscopy analysis, SEM), mechanical properties (compressive test, three-point bending test, impact strength), viscoelastic behavior (Dynamic Mechanical Analysis, DMA), thermal properties (Thermogravimetric Analysis, TGA, thermal conductivity) and application properties (contact angle, water absorption). The results showed that the morphology of modified foams is significantly affected by the fillers typology, which resulted in inhomogeneous, irregular, large cell shapes and further affected the physical and mechanical properties of the resulting materials. RPUFs modified with AP-POSS represent better mechanical properties compared to the RPUFs modified with other POSS.

scholarly journals The Synergistic Effect of Ionic Liquid-Modified Expandable Graphite and Intumescent Flame-Retardant on Flame-Retardant Rigid Polyurethane Foams

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3095 ◽  
Author(s):  
Yongjun Chen ◽  
Yuanfang Luo ◽  
Xiaohui Guo ◽  
Lijuan Chen ◽  
Demin Jia
Keyword(s):  
Thermal Decomposition ◽  
Ionic Liquid ◽  
Flame Retardant ◽  
Polyurethane Foams ◽  
Molecular Structures ◽  
Intumescent Flame Retardant ◽  
Expandable Graphite ◽  
Thermal Decomposition Mechanism ◽  
Rigid Polyurethane Foams ◽  
Synergistic Flame Retardant

In this study, a nitrogen–phosphorus intumescent flame-retardant 3-(N-diphenyl phosphate) amino propyl triethoxy silane (DPES), the ionic liquid (IL) of 1-butyl-3-methyl-imidazole phosphate, and a phosphorous-containing ionic liquid-modified expandable graphite (IL-EG), were synthesized, and their molecular structures were characterized. The flame-retardant rigid polyurethane foams (RPUFs) were compounded with synergistic flame-retardant IL-EG/DPES to study the effects of the combination IL-EG and DPES on the pore structure, mechanical properties, thermal decomposition behavior and thermal decomposition mechanism of RPUF. The results showed that IL-EG/DPES had good thermal stability, and an excellent expansibility and char yield. The flame-retardant RPUF, modified with IL-EG and DPES at the ratio of 1:1, had a relatively uniform pore size, the highest compressive strength, and an excellent flame-retardant performance due to the form interwoven hydrogen bonds between IL-EG and DPES, as well as the new synergistic flame-retardant coating on the RPUF surface to restrict the transfer of gas or heat into the PU matrix.

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.

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