SU761495A1 - Method of preparing soluble polychlorophosphazene - Google Patents

Description

The invention relates to the field of production of soluble polyhalogenphosphazene, more precisely, to the field of obtaining soluble polychlorophosphazene, 5

which, unlike the fusion polymer, is of practical interest for further substitution reactions in order to obtain phosphazene elastomers, thermoplastics and fibers.

A method of producing a soluble polihlorfosfazena whereby geksahlortsiklotrifosfazena polymerization is carried out at ^200-300 C in the presence of MS 1 to ₅ which is a molecular weight regulator polihlorfosfazena, to obtain a given molecular linear polihlorfosfazenov

masses Y · 20

The disadvantages of this method are the reduction of molecular mass characteristics of the resulting polymer, as well as the need to use for the process of thick-25 wall containers.

There is also known a method of obtaining

soluble polychlorophosphazenes, according to which to increase the yield

soluble high molecular weight

polychlorophosphazene and acceleration of the process of% formation of polymerization of hexachlorocycloprifone is carried out in the presence of compounds of the formula

I4 C,

where K = CH _a , CP _e CH ₂ 0, C ₂ H ₅ CH ₂ 0,

with _{3N m} CH _{2 O;}

x = 1.5. [2].

The disadvantage of this method is the need for a special synthesis of these compounds, and most importantly - low yields and molecular mass characteristics of the resulting polychlorophosphazene.

The closest in technical essence to the present invention is a method according to which the freeze polymerization is carried out. Hexachlorocycloprifone in the melt at 200-300 ° C in the presence of catalytic amounts of water. Moreover, the original monomer is sublimated at 50 ° C / 07 mm Hg. Sublimate was recrystallized twice from dry hexane, then dried in vacuum for 15 hours and sublimated a second time to those

the same conditions [3].

The disadvantages of this method are low yield (20-48%) and the mole

3

761495

four

mass-mass characteristics of the target product (intrinsic viscosity 0.20-0.90 dol / g).

The purpose of the invention is to increase the yield and molecular weight characteristics of the target product.

This goal is achieved by the fact that in the method of obtaining polychlorophosphazene, which involves the sublimation of hexa-chlorocyclotriphosphate, followed by its polymerization in the melt at 200-300 ° C, the hexachlorocyclophrifazene is preheated at 230-260 ° C for 1-2 hours, and the sublimation is carried out at 120 -17C ° C. This ensures the production of completely soluble polychlorophosphazene with high molecular-mass. characteristics ([£ 1 = 2.0-3.0 dl / g) and high yield (70-80%) in the polymerization of hexafachlorcyclotriphosphazene in the absence of any additives.

Preheating of the monomer with its subsequent sublimation ensures the attainment of a certain quality of hexachlorocyclo triphosphazene, which is necessary for obtaining a completely soluble polymer.

The whole process, including preliminary heating of hexachlorocycloprifazene at 230-260 ° С, its sublimation at 120-170 ° С and polymerization of freeze-dried hexachlorocycloprifazene at 200-300 ° С, is carried out directly in the polymerization capacity by varying the temperature, which makes it very technological .

Example 1. In a vial with a volume of 200 ml in an argon atmosphere, 35 g of hexachlorocycloprifazene are charged, evacuated for an hour and sealed, without disconnecting from the vacuum system.

The ampoule with hexachlorocycloprifazene is immersed in a preheated oven and incubated for 2 hours at 230 ° C, after which the hexachlorocyclotriphosphazene at 120 ° C is sublimated into the free end of the ampoule, removed from the non-distilled residue (1-2%) and heated at 200 ° C for 5 hours at 300 ° C - 3 hours. At the same time receive

completely soluble in benzene, toluene, chlorobenzene, chloroform, tetrachloroethane, tetrahydrofuran, and other solvents such polihlorfosfazen yield 28 g (80% of theoretical machinery.) and (I /] ³ in benzene solution at 25 ° C -.. 3.0 dl / g

Example 2. Ampoule with hexachlorocycloprifone, prepared analogously to example 1, is held in place for one hour at 260 ° C, after which the hexachlorocyclotriphosphazene at 170 ° C is sublimated into the free end of the ampoule, sealed off from the residue and heated at 260 ° C for 10 hours The yield of polychlorophosphazene is 24.5 (70% of

15 theory), [7] = 2.2 dl / g. The polymer is completely soluble in the listed organic solvents.

Using the proposed method of obtaining soluble polychloro-20 phosphazene as compared with the existing ones ensures stable and high molecular weight characteristics of C 7] = 2.0-3.0 dl / g and yield (70-80%) of polychlorophosphazene

25 high purity of the target product ', which is especially important with its further use to obtain medical polyphosphazenes.

Claims (1)

Claim The method of obtaining soluble polychlorophosphazene by sublimation of hexachlorocycloprifazene, followed by its polymerization in the melt at 200-300 ° C, characterized in that, in order to increase the yield and molecular weight characteristics of the target product, the hexachlorocycloprifosfeneen is preheated at 230-260 ° C for 1-2 h and 40 sublimation is carried out at 120-170 ° C