Polypropane ether di-dichlorophosphate

Abstract

Polypropane ether di-dichlorophosphate was made by reacting polypropane ether glycol with excess phosphorous oxychloride. The excess phosphorous oxychloride was distilled from the reaction product under vacuum to give high purity polypropane ether di- dichlorophosphate. Polypropane ether di-dichlorophosphate is a versatile chemical intermediate that can be reacted with compounds, such as carboxylic acids, alcohols, amines, thiols, metal salts and water, to make functional materials.

Description

[0001] POLYPROPANE ETHER DI-DICHLOROPHOSPHATE

[0002] The present invention relates generally to polypropane ether di-dichlorophosphate (“ODCP”) and the synthesis and uses thereof.

[0003] BACKGROUND OF THE INVENTION Polypropane ether di-dichlorophosphate is a versatile chemical intermediate that can be reacted with compounds, such as carboxylic acids, alcohols, amines, thiols, metal salts and water, to make functional materials. It can also be used as a starting material for the production of polypropane ether di-monophosphate which is useful in acid stabilization of polyurethane prepolymers. Hansel et al., U.S. patent 9,920,081, describes a two-step synthesis of halogen free oligomeric mixtures of poly(alkylene phosphates). In the first step, excess phosphoryl oxychloride is reacted with a monomeric glycol to give an oligomeric mixture of poly(alkylene chlorophosphates). In the second step, the poly(alkylene chlorophosphates are treated with excess ethanol to give oligomeric poly(alkylene phosphates). Unlike Hansel, in the present invention an excess of phosphoryl chloride is used to minimize oligomer formation. Moreover, in the present invention the number of repeating groups, n, from the first step of the synthesis is essentially zero, unlike Hansel et al. who teach the number of repeating groups should be greater than 1.2 and less than

[0004] 1.9.

[0005] Mezianes, et. al. report in the Journal of Chemistry, Volume 2016, Article ID 8046893 the synthesis of alkylene diphosphoric acids. The acid is obtained by reacting excess phosphoryl chloride with a low molecular diol using three different synthetic procedures. The paper teaches away from the present invention in that it reacts a pure low molecular weight diol with excess phosphoryl chloride (2.2 to 4.0:1.0 mole ratio) to produce a pure low molecular weight alkylene diphosphoric acid compounds. In the present invention an oligomeric diol is end capped with phosphoryl dichloride groups to make a reactive oligomer. Mezianes, et. al. also use laboratory procedures that are not suitable to industrial processes, such as solvents, base acceptors and microwave irradiation. In the present invention a large excess of phosphoryl chloride (greater than a 5.0 : 1.0 ratio) is used as both a reactant and a solvent. The large excess of phosphoryl chloride favors the end capping reaction. The excess phosphoryl chloride is easily distilled from the reaction mixture and recycled into subsequent batches.

[0006] It has been surprisingly found that polypropane ether glycol can be reacted with phosphoryl chloride to make a stable reactive intermediate containing phosphoryl chloride end groups. Surprisingly, only polypropane ether glycol can be effectively end capped in quantitative yield and high purity. The reaction of common poly glycols, such as polyethylene ether glycol, polypropylene ether glycol and polytetramethylene ether glycol, all resulted in degradation products from undesirable side reactions. In contrast, polypropane ether glycol is not degraded by phosphoryl chloride and forms a condensation product. As noted, polypropane ether di-dichlorophosphate is a versatile chemical intermediate that can be reacted with compounds, such as acids, alcohols, amines, thiols, metal salts and water. Such compounds are expected to find uses such as acid stabilizers for urethane prepolymers, surfactants, plasticizers and other industrial applications.

[0007] If not otherwise stated herein, it is to be assumed that all patents, patent applications, patent publications and other publications mentioned and cited herein are hereby fully incorporated by reference herein as if set forth in their entirety herein.

[0008] BRIEF SUMMARY OF THE INVENTION

[0009] There is broadly contemplated, in accordance with at least one presently preferred embodiment of the present invention, an oligomeric di-monophosphate acid stabilizer conforming to the structure of formula (I):

[0010] where n is greater or equal to 3.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] ODCP can be made using readily available starting materials and by standard reaction equipment and processes within the knowledge of those skilled in the art of chemical synthesis. In one approach, ODCP is formed by reacting polypropane ether glycol with excess phosphorous oxychloride. The excess phosphorous oxychloride was distilled from the reaction product under vacuum to give high purity polypropane ether di-dichlorophosphate. The reaction scheme can be represented by the following reaction (I): Although the preferred embodiments of the present invention are described herein, it is to be understood that the invention is not limited to that precise embodiment, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. As used in this description and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. The following examples are illustrative of a practice of the invention, but are not meant as limiting the scope of the invention.

[0013] EXAMPLES Synthesis of polypropane ether di-dichlorophosphate

[0014] 276.1 g (1.801 mol, 5.402 eq.) of phosphoryl chloride was charged to a 500 mL round bottom flask equipped with a mechanical stirrer, electric heating mantle, thermocouple, addition funnel, gas inlet and outlet adaptors. A steady flow of nitrogen gas was passed through the reactor to a bubbler that contained mineral oil. The outlet of the bubbler was connected to a water trap to remove acid from the outlet gas stream.

[0015] 100.0 g of polypropanediol (MW = 555.4 g / mol, 0.1801 mol, 0.3601 eq.) was charged to the addition funnel. The polyol was added over a 50 minute period without external heating. The batch temperature reached 40°C at the end of the addition period and extemal heating was applied. The batch was heated to 50°C and after 4 hours HC1 gas generation had stopped, which indicated the reaction was complete. The batch was cooled to room temperature and stored overnight under a nitrogen pad.

[0016] The 500 mL round bottom flask was equipped for vacuum distillation. The phosphoryl chloride was collected in a 500 mL vacuum trap that was placed in a Dewar flask and cooled with a dry ice acetone mixture. The pressure and temperature were adjusted such that steady boiling occurred in the flask. The contents of the flask were maintained at 50°C for 4 hours and 2.5 mbar. The product was a clear light straw colored liquid and was stored under nitrogen. The distillated was a clear colorless liquid and was stored under nitrogen.

[0017] The structure of the product was confirmed to be polypropane ether didichlorophosphate by 1H, 13C, and 31P{1H} NMR. The distillate was essentially pure phosphoryl chloride by 1H and 31P{1H} NMR spectroscopy.

[0018] Attempted synthesis of polypropylene ether di-dichlorophosphate 240.4 g (1.568 mol, 4.704 eq.) of phosphoryl chloride was charged to a 500 mL round bottom flask equipped with a mechanical stirrer, electric heating mantle, thermocouple, addition funnel, gas inlet and outlet adaptors. A steady flow of nitrogen gas was passed through the reactor to a bubbler that contained mineral oil. The outlet of the bubbler was connected to a water trap to remove acid from the outlet gas stream.

[0019] 159.6 g of polypropylene ether glycol (MW = 1018 g / mol, 0.1568 mol, 0.3136 eq.) was charged to the addition funnel. 25 mL of the polyol was charged to the reactor. There was no change in temperature and no HC1 gas evolution. The mixture was heated and at 58°C and slow HC1 gas evolution was noticed. The mixture was heated to 80°C and the remainder of the polyol was charged. Within 30 minutes the solution became black and the temperature started to rapidly increase. The reaction was aborted. The results show that side reactions were competing with phosphorylation.

[0020] Attempted synthesis of polytetramethylene ether di-dichlorophosphate 277.7 g (1.811 mol, 5.433 eq.) of phosphoryl chloride was charged to a 500 mL round bottom flask equipped with a mechanical stirrer, electric heating mantle, thermocouple, addition funnel, gas inlet and outlet adaptors. A steady flow of nitrogen gas was passed through the reactor to a bubbler that contained mineral oil. The outlet of the bubbler was connected to a water trap to remove acid from the outlet gas stream. 122.3 g of polytetramethylene ether glycol (MW = 675 g / mol, 0.1812 mol, 0.3624 eq.) was charged to the addition funnel. The polyol was added dropwise to the reactor and little reaction occurred. The mixture was heated to 70°C and a slow generation of HC1 gas was observed. A gel like material formed and the mixture became a slurry. The reaction was aborted. The results show that side reactions were competing with phosphorylation.

[0021] Atempted synthesis of polyethylene ether di-dichlorophosphate

[0022] 287.1 g (1.872 mol, 5.617 eq.) of phosphoryl chloride was charged to a 500 mL round botom flask equipped with a mechanical stirrer, electric heating mantle, thermocouple, addition funnel, gas inlet and outlet adaptors. A steady flow of nitrogen gas was passed through the reactor to a bubbler that contained mineral oil. The outlet of the bubbler was connected to a water trap to remove acid from the outlet gas stream.

[0023] 112.9 g of polyethylene ether glycol (MW = 603 g / mol, 0.1872 mol, 0.3745 eq.) was charged to the addition funnel. 20 mL of the polyol was added dropwise to the reactor and a mild exothermic reaction occurred. The remainder of the polyol was added dropwise in 10 mL amounts and the mixture was heated in 5°C increments to 60°C. A steady evolution of HC1 gas was noted. After 5 hours the reaction appeared complete and the reaction mixture developed a dark color. The batch was cooled to room temperature and stirred overnight under a nitrogen pad.

[0024] The 500 mL round bottom flask was equipped for vacuum distillation. The phosphoryl chloride was collected in a 500 mL vacuum trap that was placed in a Dewar flask and was cooled with a dry ice acetone mixture. The pressure and temperature were adjusted such that steady boiling occurred in the flask. The contents of the flask were maintained at 50°C for 4 hours and 2.9 mbar. The product was a black liquid that contained small black particles and was stored under nitrogen. The distillated was a clear colorless liquid and was stored under nitrogen. 1H, 13C, and 31P{ 1H} NMR spectroscopy of the soluble portion of the product showed that significant degradation had occurred. The average PEG chain length decreased from an average of 13.67 monomer units in the starting polyol to 2.26 monomer units in the reaction products. The end groups of the reaction product contained about 54 % of the phosphorylated end groups and about 46 % of -OCH2CH2C1 end groups. 1H, 13C, and 31P{ 1H} NMR spectroscopy showed that the distillate was a mixture of phosphoryl chloride (75 %) and 1,4-dioxane (25 %). The presence of 1,4- dioxane in the distillate shows that the polyethylene glycol chain was degraded in the acidic reaction media.

Claims

What is claimed is:

1. A compound conforming to the structure of formula (I):where n is > 3.