Melamine, silica, and ionic liquid as a novel flame retardant for rigid polyurethane foams with enhanced flame retardancy and mechanical properties

2020 ◽  
Vol 87 ◽  
pp. 106511 ◽  
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Krzysztof Strzelec ◽  
Agnė Kairytė ◽  
Arūnas Kremensas
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Polyurethane Foams ◽  
Rigid Polyurethane Foams

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.

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 effects of N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol on the flame retardancy and physical–mechanical properties of rigid polyurethane foams

2018 ◽  
Vol 36 (6) ◽  
pp. 535-545 ◽  
Author(s):  
Daikun Jia ◽  
Yi Tong ◽  
Jin Hu
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Initial Decomposition Temperature ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Upper Limit

Flame-retardant rigid polyurethane foams incorporating N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol have been prepared. After adding N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol, the density and compressive strength of the polyurethane foams were seen to decrease. The flame retardancy of the polyurethane foams has been characterized by limiting oxygen index, upper limit–94, and cone calorimeter tests. The polyurethane foam with 2.27 wt% N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol gave a highest limiting oxygen index of 33.4%, and the peak heat release rate of polyurethane foam reduced to 19.5 kW/m2 from 47.6 kW/m2 of PU-0 without N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol. Upper limit–94 revealed N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol did not change the burning rating, and all polyurethane foams had passed V-0 rating. The thermal stability of polyurethane foams has been investigated by thermogravimetric analyzer. N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol significantly increased the initial decomposition temperature of polyurethane foams and their residues. In addition, the morphology of residual char from the flame-retarded polyurethane foams after cone calorimeter tests has also been characterized by digital photographs. The results indicated that N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol significantly enhanced the strength and compatibility of the char layer formed by the polyurethane foams. These results indicate that N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol can improve both the quality and quantity of the char, which has a significant effect on the flame-retardant properties of the foam.

New polyols with isocyanuric structure by thiol-ene “click” chemistry reactions

2016 ◽  
Vol 53 (6) ◽  
pp. 639-662 ◽  
Author(s):  
Ram K Gupta ◽  
M Ionescu ◽  
X Wan ◽  
D Radojcic ◽  
N Bilic
Keyword(s):  
Mechanical Properties ◽  
Click Chemistry ◽  
Flame Retardancy ◽  
Reaction Rates ◽  
Polyurethane Foams ◽  
Storage Tanks ◽  
Rigid Polyurethane Foams ◽  
High Yields ◽  
Pu Foams ◽  
Very High

New polyols with isocyanuric structure were synthesized by thiol-ene “click” chemistry of triallyl isocyanurate with 1-thioglycerol and 2-mercaptoethanol. The synthesized polyols, prepared with high reaction rates and in very high yields, were chemically and structurally characterized. These polyols were used for the preparation of rigid polyurethane foams with excellent physical–mechanical properties and inherent flame retardancy. By alkoxylation of isocyanuric polyols with propylene oxide and/or ethylene oxide in a self-catalytic process, odorless polyols with lower hydroxyl numbers and lower viscosities were obtained, leading to PU foams with good properties, but without inherent flame retardancy. The synthesized polyols with isocyanuric structure are suitable for the preparation of all types of rigid polyurethane foams, including thermoinsulation of freezers, buildings, storage tanks and pipes for the food and chemical industry, for packaging, and as wood substitutes.

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.

scholarly journals Establishment of a highly efficient flame-retardant system for rigid polyurethane foams based on bi-phase flame-retardant actions

RSC Advances ◽  
2018 ◽  
Vol 8 (18) ◽  
pp. 9985-9995 ◽  
Author(s):  
Xingxing Shi ◽  
Saihua Jiang ◽  
Jingyi Zhu ◽  
Guohui Li ◽  
Xiangfang Peng
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Polyurethane Foams ◽  
Rigid Polyurethane Foams ◽  
Highly Efficient

The combination of EG and HQ has been found to endow a PU matrix with excellent gas–solid bi-phase flame retardancy.

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