Fritz Nauer AG

Switzerland

Fritz Nauer AG

Switzerland

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News Article | November 10, 2016
Site: www.eurekalert.org

We frequently encounter polyurethane (PU) foams in everyday life: they are in the insulation in house façades and refrigerators, in car seats, in living room sofas and in shoe soles. PU mostly consists of carbon, hydrogen, nitrogen and oxygen atoms. As the air trapped in the foam's pores also contains oxygen, the foam is highly flammable like most organic polymers and a flame retardant has to be incorporated in it to reduce the risk of fire. In recent decades, foam manufacturers usually used chlorinated phosphate as a flame retardant - a cost-effective additive that doesn't disrupt the production process. However, many of these chlorinated fire retardants are toxic and can evaporate from the foam over time and get into the ambient air. Consequently, these substances are already forbidden in many countries. The industry is urgently looking for environment friendly and non-toxic alternatives. Additionally, the PU foam market is huge: almost 20 million tons of PU foam are produced worldwide every year, the majority of which needs flame retardant additives. Sabyasachi Gaan and his research team patented a family of derivatives based on DOPO (9,10-dihydro-10-oxa-phosphaphenanthrene oxide) which offers the desired properties. In particular, 6,6'-(ethane-1,2-diylbis(azanediyl))bis(6H-dibenzo[c,e][1,2]oxaphosphinine-6-oxide) (EDA-DOPO) fulfills technical, economic and environmental criteria. The PU foams containing EDA-DOPO achieves the highest flame retardant classification in the UL 94 HB. Being a solid at room temperature, it is unable to evaporate from the foam later on and thus offers an excellent solution for transportation sector. The powder also blends in well with the PU foam production process: it mixes very well with polyol, a base material for PU foam, and forms a stable dispersion, which can then be processed easily. The end result is foam where the solid flame retardant EDA-DOPO is finely distributed in the PU cell walls. The prize-winning research project began in June 2013 and was financed with EU/ Swiss (CTI) research funds. Metadynea Austria GmbH and Foampartner Fritz Nauer AG in Wolfhausen were industrial partners. EDA-DOPO is currently produced on a 100-kilogram scale and under REACH Registration process.


Gaan S.,Additives and Chemistry Group | Liang S.,Additives and Chemistry Group | Mispreuve H.,Additives and Chemistry Group | Mispreuve H.,Fritz Nauer AG | And 5 more authors.
Polymer Degradation and Stability | Year: 2015

In this work we report synthesis and flame retardant application of novel 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) based phosphonamidates. Two mono and one bis DOPO-phosphonamidates were synthesized and incorporated in polyether based polyurethane (PU) manufacturing process. For the comparison of fire performance of these DOPO-phosphonamidates, we have chosen commercially available flame retardants (TCPP, DOPO and Exolit® OP 560) commonly used in flexible PU foam manufacturing. UL94 HBF fire results of various PU foam formulations indicate that DOPO-phosphonamidates exhibit superior fire performance as compared to the commercial flame retardants. 6,6′-(ethane-1,2-diylbis-(azanediyl)-bis-(6H-dibenzo[c,e][1,2]-oxaphosphine-6-oxide (EDAB-DOPO))/foam formulations exhibit the best fire performance as compared to other DOPO-phosphonamidate/foam formulations. A concentration of only 5% EDAB-DOPO on wt. of polyol is needed to achieve a HF1 rating. Thermal decomposition studies of the DOPO-phosphonamidate/foam formulations indicate their limited condensed phase interaction. In TGA experiments, a very small residue (<5%) was observed at 800 °C for all PU formulations. Additionally EDAB-DOPO showed evidence of intermediate condensed phase interaction in the first stage of PU foam decomposition. Direct insertion probe (DIP) - MS studies indicate that mono DOPO-phosphonamidates volatilize primarily in the first stage of thermal decomposition of PU foams whereas the EDAB-DOPO, being thermally more stable is only detected in gas phase in the second stage. Like in case of TCPP/PU foam formulation, the increase in the CO/CO2 ratio in the cone calorimeter experiments for the DOPO-phosphonamidate/foam formulation further proves the gas phase activity (flame inhibition) of these DOPO-phosphonamidates. EDAB-DOPO being thermally more stable seems to offer more sustained gas phase activity during the entire burning stage of PU foams in cone calorimeter experiments. Higher thermal stability of EDAB-DOPO may explain its superior flame retardant efficacy among all the DOPO-phosphonamidates investigated in this study. © 2015 Elsevier Ltd. All rights reserved.


Liang S.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Neisius M.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Mispreuve H.,Fritz Nauer AG | Naescher R.,Fritz Nauer AG | Gaan S.,Empa - Swiss Federal Laboratories for Materials Science and Technology
Polymer Degradation and Stability | Year: 2012

In this study the structural effect of different phosphorus compounds on the flame retardant (FR) properties of flexible polyurethane foams (FPUF) was investigated. A series of organophosphorus compounds (phosphonates, phosphates and phosphoramidates) with systematical structure variations were synthesized and incorporated into the flexible foam during its polymerization process. The flameretarding efficiency of these phosphorus compounds was subsequently evaluated by subjecting their corresponding flame-retarded foams to standard fire tests such as limiting oxygen index (LOI), BKZvertical burning test and UL 94-horizontal burning test for foamed materials. It was observed that the synthesized phosphonates and analogous phosphoramidates were more effective than the corresponding phosphates. The presence of an allyl moiety within the molecular structure further improved the FR efficacy of the phosphonate and phosphoramidate compounds, whereas a benzyl group reduced the flame retardant efficiency significantly. The thermogravimetric (TGA) analysis and pyrolysis combustion flow calorimetry (PCFC) results for the FPUF indicated that the most effective FRs might act predominantly in gas phase and exhibit lower condensed phase action (i.e. catalyze the decomposition of FPUF to happen at lower temperatures). Mass spectrometric analysis of FRs indicates that phosphonate and phosphoramidate derivatives appear to support the phosphoryl radical formation more than the investigated phosphate compounds. © 2012 Elsevier Ltd. All rights reserved.


Stelzig T.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Buczko A.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Bommer L.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Liang S.,Empa - Swiss Federal Laboratories for Materials Science and Technology | And 4 more authors.
25th Annual Conference on Recent Advances in Flame Retardancy of Polymeric Materials | Year: 2014

DOPO-phosphonamidates: Green synthesis method-alternative to CCl4 chlorination, dispersion of solid FR in PU foams, application in PU foams, thermal stability and compatibility in PA6. New FRs: (Meltable) concept of hybrid FRs, suitable for thin walled application(fibers, EPs) in polyesters, new P and N FRs for Epoxy resins.


Gaan S.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Neisius M.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Cuchere O.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Liang S.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Mispreuve H.,Fritz Nauer AG
Fire Safety Science | Year: 2014

Development of new halogen-free flame retardants for application in polymer is becoming important due to ban of some existing halogenated flame retardants, ineffectiveness of existing flame retardant additives and higher fire performance requirements for materials. Polyurethane is an important class of polymer finding application in diverse areas like textile coatings, wood coatings, foams, fibers, cables, adhesives etc. There is a great need to develop halogen free flame retardants for various PU based materials. In this work we have reported synthesis of novel phosphonamidates as flame retardant additives and their application in manufacturing flame retardant flexible PU foams and flame retardant polyester PU coated fabrics. Furthermore the flame retardant properties and thermal decomposition characteristics of the PU based materials have been evaluated. The novel phosphonamidate derivatives have superior fire performance properties as compared to existing commercial flame retardant additives and work primarily in gas phase by recombining H∗ and OH∗ radicals. © Copyright 2014 International association for fire safety science.


Neisius M.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Liang S.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Mispreuve H.,Fritz Nauer AG | Gaan S.,Empa - Swiss Federal Laboratories for Materials Science and Technology
Industrial and Engineering Chemistry Research | Year: 2013

In this study, we have investigated the structure-flame-retardant (FR) efficacy relationships of phosphoramidates (PRs) on flexible polyurethane foam (FPUF). FPUFs that contain model monosubstituted secondary PRs, monosubstituted tertiary PRs, and trisubstituted secondary PRs were prepared and evaluated for FR efficacy and thermal decomposition characteristics. The fire test results indicate that methyl ester PRs exhibit better FR behavior, compared to analogous phenyl ester derivatives at equal weight percentage in polyurethane (PU) foams. Within the same class of PRs, the monoallyl derivatives exhibited the highest level of flame retardancy. The multiallyl PR derivatives did not offer any advantage, in terms of improved flame retardancy. Evolved gas analysis from the thermal degradation of PU foams indicates that the PRs are volatilized in the first stage of thermal decomposition and are primarily active in the gas phase with the exception of the triallyl-PR derivative, which is primarily active in the condensed phase. © 2013 American Chemical Society.


Neisius N.M.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Liang S.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Mispreuve H.,Fritz Nauer AG | Gaan S.,Empa - Swiss Federal Laboratories for Materials Science and Technology
ACS Symposium Series | Year: 2012

This short review is focused on scientific developments and studies inflame retardancy of flexible polyurethane (PU) foams that has been published during the last three years. Since an increasing number of brominated flame retardants are banned and chloro-phosphate esters like TCEP, TDCPP, TDCP are either banned or under investigation by environmental agencies, the industrial and academic flame retardant research in PU foams has gained impetus. It is a mutual understanding that more environmentally benign and less hazardous materials should be used in the future. In the first part of this article we have reviewed the recent efforts of various research groups towards the development of such kind of flame retardants for PU foams. The second part of this article details some investigations on possible synergistic or antagonistic interactions between phosphoramidate compounds and melamine inflame retardancy of flexible polyurethane foam (FPUF). © 2012 American Chemical Society.


Patent
Fritz Nauer Ag, Empa - Swiss Federal Laboratories for Materials Science and Technology | Date: 2012-08-06

A group of novel compounds containing one or more amino substituted DOPO (9,10-dihydro-9-oxa-phosphaphenthren-10-oxide) moieties. The compounds were found to have good flame retardant properties and also good thermal stability, which makes them particularly suitable as flame retardant additives for various thermoplastic polymers. In particular, they can be incorporated in a polyurethane foam.


The invention relates to a group of novel compounds containing one or more amino substituted DOPO (9,10-dihydro-9-oxa-phosphaphenthren-10-oxide) moieties. The compounds were found to have good flame retardant properties and also good thermal stability, which makes them particularly suitable as flame retardant additives for various thermoplastic polymers. In particular, they can be incorporated in a flexible polyurethane foam.

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