Synthesis and studies of phosphorus‐containing polyurethane foams based on tetrakis(hydroxymethyl) phosphonium chloride derivatives

Abstract

synopsisA phosphorus-and nitrogen-containing polyol is prepared by condensing tetrakis(hydrox ymethy1)phosphonium chloride with diethanol amine in aqueous medium. The newly synthesized p o l y o l -b i s ( h y d r o x y m e t h y l ) -~~-b i a ( 2 -h y~~e t h y l )~o m e~y l p h~p~eoxide (-0) is used in the preparation of rigid polyurethane foams with a various phosphorus content. With the view to comparing their properties, polyurethane foams are also prepared on the basis of the commercially available flame retardant diethyl-NJv-bis(2-hydroxyethyl)aminomethylphosphonate (FyroL 6). The hmnability, thermal stability, and thennomechanical properties of the polyurethane foams obtained are studied. A certain difference in the behavior of the two m&ied polyurethane foams is observed. The polyurethane foams with AMP0 exhibit a slight increase in the resistance to combustion (oxygen index) and a noticeable improvement in the thermal and mechanical properties. These differences probably arise as a result of structural and functional differences between the two types of phoaphorus:containing flame retardants. INTRODUCTIONThe use of phosphorus-containing flame retardants is one of the well-known methods for improving the resistance to combustion of polyurethane Tetrakis(hydroxymethy1)phosphonium chloride and its tris(hydroxymethy1)-phosphine and tris(hydroxymethy1)phosphine oxide derivatives noted for their high reactivity, as well as for their accessibility, are convenient starting compounds for the synthesis of monomers and polymers with C-P bond^.^^^ The phosphorus methylol derivatives are also successfully employed as reactive flame retardants in the preparation of polyurethanes with reduced flammability and improved stability to hydrolysis. Tetrakis(hydroxymethy1)phosphonium chloride and its derivatives? as well as their reaction products with alkylene osides6-7 and hydroxyl group containing comp0und9,8~~ have been separately or in mixtures with commercially available polyols.Aminomethylphosphine oxides prepared from tetrakis(hydroxymethy1)-phosphonium chloride and polyfunctional amines fmd considerable application in improving the resistance to combustion of t e~t i l e s .~*~J~ The products, crosslinked polymeric aminomethylphosphine oxides, have not been isolated, but are formed on impregnation and subsequent treatment of the textile mate- rials. Methylol derivatives of phosphorus with secondary amines have been reported; they are, however, mainly tris( aminomethy1)phosphine or phosphine oxides.11-14 They are devoid of reactive substituents, and in this way their usefulness in the field of polymers is limited.The aim of the present work is the synthesis ofa phosphorus-and nitrogencontaining polyol from tetrakis(hydroxymethy1)phosphonium chloride and diethanol amine and its use in the preparation of rigid polyurethane foams with reduced flammability. The structure and composition of the synthesized polyol were also examined with the view to elucidating their influence on certain properties, chiefly the resistance ...

Inherently Flame-Retardant Flexible Polyurethane Foam with Low Content of Phosphorus-Containing Cross-Linking Agent

“…In general, reactive-type flame retardants are mostly based on halogens and phosphorus. − Recently, selected halogen-containing flame retardants have been banned because they have poor environmental profiles, along with some human health and toxicity effects. For this reason, there is a strong desire to develop effective nonhalogenated flame retardants with superior environmental profiles and the ability to react with foams and not leach into the environment. , It has been widely demonstrated that the most suitable reactive flame retardants for rigid polyurethane foams are mainly phosphorus-containing polyols, such as 2,2′-((bis(hydroxymethyl) phosphoryl)methylazanediyl)diethanol, tris(dipropylene glycol)phosphonate, diethyl- N , N ′-bis(2-hydroxyethyl)aminomethylphosphonate, diethyl- N , N ′-diethanolaminomethylphosphate, and morpholinophosphoryldimethanol. ,, Several new phosphorus-containing polyols, based on tetrakis(hydroxymethyl)phosphonium chloride (THPC), have been used for rigid polyurethane foams, being introduced into the polyurethane main chain in the chain-extension step. ,− Moreover, the modified rigid polyurethane foams showed good flame resistance. Usually, these phosphorus-containing polyols are used as chain extenders or reactive monomers for rigid polyurethane foams; however, they are rarely used for FPUF.…”

The Effect of Polyepoxyphenylsilsesquioxane and Diethyl Bis(2-hydroxyethyl)aminomethylphosphonate on the Thermal Stability of Epoxy Resin

“… 14 − 22 A phosphorus-containing organic compound, diethyl bis(2-hydroxyethyl) aminomethylphosphonate (DBAMP), has attracted intensive attention due to its high rate of performance and price. 23 Silicone flame retardants not only endow EP with excellent flame retardancy but also improve the processing properties, heat resistance, and so on. In addition, they do not release toxic gas during combustion.…”

“…This is mainly because the products of phosphorous compounds decomposed by heat have a very strong dehydrating effect, which can make the surface of the covered polymer carbonized, form the char layer to isolate the air, and thus play the role as a condensation phase flame retardant. At present, phosphorus-containing organic compounds of various structures have been reported as flame retardants for EP. − A phosphorus-containing organic compound, diethyl bis­(2-hydroxyethyl) aminomethylphosphonate (DBAMP), has attracted intensive attention due to its high rate of performance and price . Silicone flame retardants not only endow EP with excellent flame retardancy but also improve the processing properties, heat resistance, and so on.…”

The Use of Ammonium Salts of Oligosulphonic Acids as Flame Retardants for Polymer Compositions

“…Flame retardant polyurethane foams were prepared by modification with phosphorus-and nitrogencontaining polyols 25 . Tertiary polyfunctional amines (containing hydroxyl, thiol and amino groups), with alkyl, cycloalkyl and phenyl radicals were used for polyurethane stabilisation 26 .…”