Phthalonitrile Monomer Modified with Organophosphorus Fragments, a Method of Producing thereof, a Binder Based Thereon, and a Prepreg

Abstract

A method of obtaining modified phthalonitriles comprising organophosphorus fragments, binding agents based thereon, and products produced with the use thereof, can be used in a variety of fieldsfrom aircraft and automobile manufacturing to producing polymer composite materials. The method makes it possible to produce phthalonitrile monomers comprising organophosphorus fragments from simpler and cheaper reagents and to obtain them as individual substances, simplifying the process of synthesis, reducing the glass transition temperature of monomers and increasing the thermal oxidation stability of hardened polymers. The phthalonitrile monomer modified with organophosphorus fragments is characterized by the following general formula:

##STR00001##

wherein R is a radical selected from the group comprising aryl, alkyl, aryloxy or alkyloxy substituents; and X is a divalent aryl substituent selected from a group comprising phenylenes and naphthylenes. Also disclosed is a method of obtaining the modified phthalonitrile monomer, a binder, and a prepreg based on the same.

Claims

1. A phthalonitrile monomer modified with organophosphorus fragments, the phthalonitrile monomer having a general formula of: ##STR00018## wherein R is a radical selected from the group consisting of aryl, alkyl, aryloxy and alkyloxy substituents; and X is a divalent aryl substituent selected from the group consisting of phenylenes and naphthylenes.

2. The phthalonitrile monomer according to claim 1, wherein R is the radical selected from the group consisting of OCH.sub.3, OC.sub.6H.sub.5, OC.sub.10H.sub.7 and C.sub.6H.sub.5.

3. A method of obtaining a phthalonitrile monomer modified with organophosphorus fragments, the phthalonitrile monomer having a general formula of: ##STR00019## wherein R is a radical selected from the group consisting of aryl, alkyl, aryloxy and alkyloxy substituents, andX is a divalent aryl substituent selected from the group consisting of phenylenes and naphthylenes, the method comprising performing a reaction between at least one hydroxyl-containing phthalonitrile and a phosphorus-containing substance selected from the group consisting of alkyl- or arylphosphoric acid, alkyl- or arylphosphorous acid, anhydrous dichloride of alkyl- or arylphosphoric acid and anhydrous dichloride of alkyl- and arylphosphorous acid, subsequently extracting a target product from reaction products in a form of the phthalonitrile monomer modified with the organophosphorus fragments.

4. The method according to claim 3, wherein the at least one hydroxyl-containing phthalonitrile is selected from the group consisting of (4-(2-hydroxyphenoxy)phthalonitrile, 4-(3-hydroxyphenoxy)phthalonitrile and 4-(4-hydroxyphenoxy)phthalonitrile).

5. The method according to claim 3, further comprising mixing said hydroxyl-containing phthalonitrile with an acceptable solvent prior to performing the reaction.

6. The method according to claim 3, further comprising performing the reaction in a presence of a base.

7. The method according to claim 3, wherein extracting the target product is performed by sequential stages of filtering of the reaction products and obtaining a filtrate, evaporating the filtrate, dissolving an evaporation product, washing a solution with water and extracting the target product therefrom.

8. A binder comprising a phthalonitrile monomer modified with organophosphorus fragments, the phthalonitrile monomer having a general formula of: ##STR00020## wherein R is a radical selected from the group consisting of aryl, alkyl, aryloxy and alkyloxy substituents, and X is a divalent aryl substituent selected from the group consisting of phenylenes and naphthylenes; and an aromatic diamine as a polymerization initiator.

9. The binder according to claim 8, wherein an amount of the aromatic diamine is up to 20% by weight.

10. The binder according to claim 8, wherein the binder is used to obtain polymer composite materials by infusion technology.

11. A prepreg made of a binder comprising; a phthalonitrile monomer modified with organophosphorus fragments having a general formula of: ##STR00021## wherein R is a radical selected from the group consisting of aryl, alkyl, aryloxy and alkyloxy substituents, and X is a divalent aryl substituent selected from the group consisting of phenylenes and naphthylenes; an aromatic diamine as a polymerization initiator; and a reinforcing element.

12. The prepreg according to claim 11, wherein the reinforcing element is selected from the group consisting of unidirectional carbon tapes, carbon fabrics, fiberglass fabrics, unidirectional fiberglass tapes, chopped carbon fibers, and chopped fiberglass fibers.

13. The prepreg of claim 11, wherein an amount of the aromatic diamine is up to 20% by weight.

14. The prepreg of claim 11, wherein the binder is used to obtain polymer composite materials by infusion technology.

15. The binder of claim 8, wherein R is the radical selected from the group consisting of OCH.sub.3, OC.sub.6H.sub.5, OC.sub.10H.sub.7 and C.sub.6H.sub.5.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] FIG. 1 shows the relationship between the mass loss of a hardened phthalonitrile and the heating temperature in the air for the oligomer according to this invention (4a), the monomer according to U.S. Pat. No. 4,587,325 (4b) and the monomer according to patent RU2580927 (1b).

[0081] As follows from the data in FIG. 1, the phthalonitrile monomer as per this invention withstands heating to temperatures above 500 C., with gradual deterioration of its properties under further heating; the phthalonitrile according to RU2580927 withstands temperatures around 420 C., with a dramatic increase of mass loss under further heating. A similar behavior is demonstrated by the phthalonitrile oligomer according to US2011263775.

TABLE-US-00001 TABLE 1 Properties of obtained monomer Glass transition temperature, Monomer R X Tgt, C. [00008] OC.sub.6H.sub.5 1,3 phenylene 22 [00009] OC.sub.10H.sub.7 1,3 phenylene 58 [00010] OC.sub.3H.sub.3 1,3 phenylene 4 [00011] OC.sub.6H.sub.5 1,4 phenylene 50 [00012] C.sub.6H.sub.5 1,3 phenylene 42

TABLE-US-00002 TABLE 2 Hardened monomer (binder)* properties Start of Start of Softening decomposition decomposition temperature, in argon, in argon, T.sub.soft (heat (loss of 5% Carbon (loss of 5% Ash resistance), of mass), residue, of mass), residue, Monomer C. T.sub.5%, C. % T.sub.5%, C. % [00013] 455 524 80 523 29 [00014] 512 77 516 6 [00015] 441 518 80 514 49 [00016] 514 78 501 37 [00017] 498 72 494 15 *Binders prepared according to Examples 6 and 7 and hardened according to Example 8 in the presence of 4% diamine P (PPD).