RU2738836C1 - Solvent and method of processing polyketone and/or polyamide using same (embodiments) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: present invention relates to a solvent for polyamide and/or polyketone, as well as to a method of processing polymer by dissolving it in a solvent. Invention can be used to produce polymer films, membranes, fibres and other articles for use in various industries. Solvent for polyamide and/or polyketone consists of a mixture of benzyl alcohol and an organic co-solvent with Hansen's dispersion solubility parameter of not less than 16.5 MPa^0.5, with the following ratio of components, wt. %: benzyl alcohol 30–70; cosolvent - balance. Method of processing the polymer involves dissolving it in a solvent, forming the obtained polymer solution and removing the solvent to obtain the desired polymer product, in which the polymer used is polyamide and/or polyketone, which is dissolved in the disclosed solvent to obtain a polymer solution, with the following ratio of components, wt. %: polyamide and/or polyketone 0.1–30; solvent - balance.

EFFECT: present invention makes it possible to expand methods of processing polyketone and polyamide, to reduce toxicity and viscosity of their solutions, and also enables their combined processing.

6 cl, 1 tbl, 17 ex

Description

The invention relates to the field of physical chemistry of high-molecular compounds, specifically to the formulation of mixed solvents for aliphatic polyketone and moisture-resistant polyamide, a method for their dissolution and processing through solutions and can be used to obtain polymer films, membranes, fibers and other products for use in various sectors of the national economy ...

One of the main ways to process polymers is through solutions. This method makes it possible to obtain polymer membranes intended for gas separation, dialysis, membrane distillation, nano-, ultra- and microfiltration, as well as to form polymer fibers by dry, wet or dry-wet methods and using electrospinning.

For a number of industrial applications, high demands on chemical resistance in various environments can be imposed on the material of fibers and membranes. The range of chemically stable polymers is limited, and their chemical resistance results in their insolubility in almost all known liquids.

Chemically resistant polymeric materials for special purposes include aliphatic polyketone (copolymer of carbon monoxide, ethylene, propylene and other olefins) and aliphatic moisture resistant polyamides - polyundecanamide and polydodecanamide, respectively; hereinafter referred to as polyamide, since their properties are identical from the practical point of view of this invention). Polyamide and polyketone, despite their different chemical structures, have similar thermodynamic characteristics, which are expressed in similar solubility.

It is known that polyketone (US 3689460 A) and polyamide (Fina LJ, Yu N. N. // J. Polym. Sci. B. 1992. V. 30. P. 1073; Lanska B., Bohdanecký M., Šebenda J ., Tuzar, Z. // Eur. Polym. J. 1978. V. 14. P. 807) are dissolved in m-cresol.

However, the disadvantage of using m-cresol is its high toxicity. In practice, it is used only to determine the intrinsic viscosity of polymers.

In addition, it is known that polyketone (US 4804472 A) and polyamide (Stephens JS, Chase D. B., Rabolt JF // Macromolecules. 2004. V. 37. P. 877) are soluble in 1,1,1,3,3 , 3-hexafluoroisopropanol. This solvent is not commercially produced, very expensive, flammable, toxic and corrosive to metal.

Highly concentrated aqueous and methanol solutions of zinc chloride, bromide and iodide (US 5929150 A) and lithium iodide, bromide and thiocyanate (US 5977231 A) have been proposed as a solvent for polyketone.

The disadvantages of these inventions are the high corrosive effect of aqueous solutions of salts, the toxicity of methanol, the impossibility of obtaining products from these solutions by drying them, as well as the difficulty of extracting salts from spent molding solutions for their regeneration.

It is known to use ethanol to dissolve polyketone and / or polyamide in the composition of printing ink, where a solution is obtained in ethanol of the obtained alcohol-soluble polyamide resin of a given composition and an alcohol-soluble polyketone resin of a given composition (patent CN 102585601, class IPC C09D 11/102, publ. 18.07.2012 ). This patent is chosen as the prototype for the solvent.

However, ethanol is only suitable for dissolving separately prepared alcohol-soluble polymers of a given composition, and will not be a solvent for industrially produced polyamides and polyketones, which can be processed into products such as films and fibers.

The closest analogue for the polymer processing method is a polyketone processing method by dissolving it in trifluoroacetic acid and its solutions in methylene chloride, forming the resulting polymer solution and removing the solvent to obtain the target polymer product - a membrane (Ohsawa O., Lee K. K, Kim B S., Lee S., Kim, IS // Polymer. 2010. V. 51. P. 2007). Trifluoroacetic acid is a strong acid, the high proton-donating properties of which ensure the solubility of the polyketone, and the use of a co-solvent provides a low viscosity of the resulting solutions.

The disadvantage of using trifluoroacetic acid is its high cost, strong corrosive effect on metals and plastics, as well as the high toxicity of trifluoroacetic acid and methylene chloride with its high volatility.

The objective of the invention is to develop a non-toxic cheap mixed solvent suitable for dissolving polyketone and / or polyamide and their further processing with its use in useful products.

The problem is solved by the fact that the solvent for polyamide and / or polyketone, including a proton-donor solvent - alcohol, contains benzyl alcohol as alcohol, and additionally an organic co-solvent with a dispersion solubility parameter according to Hansen of no less than 16.5 MPa ^0.5 at the following ratio of components, wt%. :

benzyl alcohol 30-70, co-solvent rest.

The problem is also solved by the fact that a method is proposed for processing a polymer by dissolving it in a solvent, shaping the resulting polymer solution and removing the solvent to obtain the target polymer product, in which polyundecanamide and / or polydodecanamide and / or polyketone are used as a polymer, which is dissolved in the claimed solvent to obtain a polymer solution with the following ratio of components, wt%:

polyamide and / or polyketone 0.1-30, solvent rest,

said molding is carried out by pouring a polymer solution onto a fluoroplastic substrate, removing the solvent by drying at a temperature of 140-160 ° C for 6 hours, and a thin-layer film is obtained as a polymer product.

The problem is also solved by the fact that a method is proposed for processing a polymer by dissolving it in a solvent, shaping the resulting polymer solution and removing the solvent to obtain the target polymer product, in which polyundecanamide and / or polydodecanamide and / or polyketone are used as a polymer, which is dissolved in the claimed solvent to obtain a polymer solution with the following ratio of components, wt%:

polyamide and / or polyketone 0.1-30, solvent rest,

said forming is carried out by placing a polymer solution between two films of polyethylene terephthalate with a polyester nonwoven fabric located between them and dipping into a precipitation bath with acetone, and a composite membrane is obtained as a polymer product.

The problem is also solved by the fact that a method is proposed for processing a polymer by dissolving it in a solvent, shaping the resulting polymer solution and removing the solvent to obtain the target polymer product, in which polyundecanamide and / or polydodecanamide and / or polyketone are used as a polymer, which is dissolved in the claimed solvent to obtain a polymer solution with the following ratio of components, wt%:

polyamide and / or polyketone 0.1-30, solvent rest,

said shaping is carried out by extrusion of a polymer solution into a precipitation bath with acetone through a forming device, and a fiber is obtained as a polymer product.

Removal of the solvent from the polymer solution to obtain a membrane or fiber is carried out by evaporation or extraction.

Benzyl alcohol is a weak acid that is not a solvent for both polyketone and polyamide due to its weak proton-donating properties. However, the combination of benzyl alcohol with a co-solvent characterized by a high level of intermolecular dispersion interactions enhances the dissolving ability of benzyl alcohol with respect to the indicated polymers, which is not obvious.

According to the proposed invention, dimethyl sulfoxide is used as a co-solvent (the dispersion solubility parameter of Hansen is 18.4 MPa ^0.5 ), tetralin (19.6 MPa ^0.5 ), alpha-bromonaphthalene (20.3 MPa ^0.5 ), sulfolane (18.0 MPa ^0.5 ), 2-pyrrolidone (19.4 MPa ^0.5 ) , ethylene carbonate (19.4 MPa ^0.5 ), cyclohexanol (17.4 MPa ^0.5 ), N-methylacetamide (16.9 MPa ^0.5 ), or any other compound with a Hansen dispersion solubility parameter of at least 16.5 MPa ^0.5, or a mixture of such compounds.

The technical result that can be obtained from the use of the invention is to expand the methods of processing polyketone and polyamide, reduce the toxicity and viscosity of their solutions, the possibility of their joint processing.

The following examples illustrate the proposed technical solution.

The solvent for polyketone and polyamide can be obtained by mixing benzyl alcohol with a co-solvent characterized by a high energy of dispersion intermolecular interactions. In this case, the cosolvent can be both polar, such as 2-pyrrolidone (Examples 1 and 2), dimethyl sulfoxide (Examples 3 and 4), cyclohexanol (Example 5), formamide (Example 6), T-methylacetamide (Example 7) or ethylene carbonate ( Example 8) and non-polar, for example, tetralin (Examples 9 and 10) or alpha-bromonaphthalene (Examples 11 and 12).

The proportions of benzyl alcohol and co-solvent in the composition of the solvent for polyketone and polyamide do not have to be equal: the solubility of polymers is maintained when the ratio of these components is varied within a fairly wide range (Examples 13 and 14).

In addition, a mixture of liquids can be used as a co-solvent (Examples 15 and 16).

The solvent thus obtained is not only capable of dissolving polyamide (Examples 1, 3, 5, 7, 9, 11, 16) and polyketone (Examples 2, 4, 6, 8, 10, 12-15) separately, but also makes it possible their joint processing (Example 17).

From solutions it is possible to obtain products, for example, films (Example 2, 5, 6) and fibers (Example 9).

To measure the viscosity of solutions, a rotary rheometer DHR-2 (TA Instruments, USA) is used using a cone-plane working unit (cone diameter 20 mm, angle between the cone and plane 2 °) at 25 ° C and a shear rate of 100 s ^-1 .

Example 1

To obtain a solvent, 0.5 g of benzyl alcohol and 0.5 g of 2-pyrrolidone are placed in a glass container and mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyamide (polydodecanamide) and heat the container to 140 ° C in order to intensify the dissolution process.

After 20 min, a clear solution forms, which remains homogeneous when cooled to 25 ° C.

Example 2

To obtain the solvent, 4.75 g of benzyl alcohol and 4.75 g of 2-pyrrolidone are placed in a glass container and mixed by shaking the container for 10 s at 25 ° C. Then 0.5 g of polyketone (copolymer of carbon monoxide, ethylene and propylene) is added to the solvent to obtain 5 wt. % polymer solution and heat the container to 180 ° C in order to intensify the dissolution process.

After 40 min, a clear solution forms, which turns into a gel on cooling to 25 ° C. A sample is taken from the sample and its viscosity is measured (Table 1).

The rest of the solution is poured onto a fluoroplastic support and dried at 160 ° C for 6 hours; as a result, a thin-layer polymer film is formed.

Example 3

To obtain a solvent, 0.5 g of benzyl alcohol and 0.5 g of dimethyl sulfoxide are placed in a glass container and they are mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyamide and heat the container to 140 ° C in order to intensify the dissolution process.

After 20 min, a clear solution forms, turning into a clear gel upon cooling to 25 ° C.

Example 4

To obtain a solvent, 0.5 g of benzyl alcohol and 0.5 g of dimethyl sulfoxide are placed in a glass container and they are mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyketone and heat the container to 180 ° C in order to intensify the dissolution process.

After 40 minutes, a clear solution forms, which remains homogeneous when cooled to 25 ° C.

Example 5

To obtain a solvent, 4.75 g of benzyl alcohol and 4.75 g of cyclohexanol are placed in a glass container and mixed by shaking the container for 10 s at 25 ° C. Then 0.5 g of polyamide is added to the solvent to obtain 5 wt. % polymer solution and heat the container to 140 ° C in order to intensify the dissolution process.

After 40 min, a clear solution forms, which turns into a gel on cooling to 25 ° C. A sample is taken from the sample and its viscosity is measured (Table 1).

The remainder of the solution is poured onto a fluoroplastic support and dried at 140 ° C for 6 hours; as a result, a thin-layer polymer film is formed.

Example 6

To obtain a solvent, 4.75 g of benzyl alcohol and 4.75 g of formamide are placed in a glass container and mixed by shaking the container for 10 s at 25 ° C. Then 0.5 g of polyketone is added to the solvent to obtain 5 wt. % polymer solution and heat the container to 180 ° C in order to intensify the dissolution process.

After 40 minutes, a clear solution forms, which remains homogeneous when cooled to 25 ° C. A sample is taken from the solution and its viscosity is measured (Table 1).

The rest of the solution is placed between two films of polyethylene terephthalate with a polyester nonwoven fabric located between them and immersed in a precipitation bath with acetone; the result is a composite membrane.

Example 7

To obtain a solvent, 4.75 g of benzyl alcohol and 4.75 g of N-methylacetamide are placed in a glass container and mixed by shaking the container for 10 s at 25 ° C. Then 0.5 g of polyamide is added to the solvent to obtain 5 wt. % polymer solution and the container is heated to 160 ° C in order to intensify the dissolution process.

After 30 min, a clear solution is formed, which turns into a gel on cooling to 25 ° C. A sample is taken from the solution and its viscosity is measured (Table 1).

Example 8

To obtain the solvent, 4.75 g of benzyl alcohol and 4.75 g of ethylene carbonate are placed in a glass container and they are mixed by shaking the container for 10 s at 25 ° C. Then 0.5 g of polyketone is added to the solvent to obtain 5 wt. % polymer solution and heat the container to 180 ° C in order to intensify the dissolution process.

After 40 min, a clear solution is formed, which turns into a gel on cooling to 25 ° C. A sample is taken from the solution and its viscosity is measured (Table 1).

Example 9

To obtain the solvent, 4.75 g of benzyl alcohol and 4.75 g of tetralin are placed in a glass container and they are mixed by shaking the container for 10 s at 25 ° C. Then 0.5 g of polyamide is added to the solvent to obtain 5 wt. % polymer solution and the container is heated to 160 ° C in order to intensify the dissolution process.

After 20 min, a clear solution is formed, which turns into a gel on cooling to 25 ° C. A sample is taken from the sample and its viscosity is measured (Table 1).

The remainder of the solution is placed into a syringe, from which the solution is then squeezed out into a precipitation bath with acetone, thereby obtaining a polymer fiber.

Example 10

To obtain a solvent, 0.5 g of benzyl alcohol and 0.5 g of tetralin are placed in a glass container and they are mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyketone and heat the container to 180 ° C in order to intensify the dissolution process.

After 30 min, a clear solution is formed, which remains homogeneous when cooled to 25 ° C.

Example 11

To obtain the solvent, 0.5 g of benzyl alcohol and 0.5 g of alpha-bromonaphthalene are placed in a glass container and mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyamide and heat the container to 140 ° C in order to intensify the dissolution process.

After 20 min, a clear solution forms, turning into a clear gel upon cooling to 25 ° C.

Example 12

To obtain the solvent, 0.5 g of benzyl alcohol and 0.5 g of alpha-bromonaphthalene are placed in a glass container and mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyketone and heat the container to 180 ° C in order to intensify the dissolution process.

After 30 min, a clear solution is formed, which remains homogeneous when cooled to 25 ° C.

Example 13

To obtain the solvent, 0.33 g of benzyl alcohol and 0.67 g of 2-pyrrolidone are placed in a glass container and mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyketone and heat the container to 180 ° C in order to intensify the dissolution process.

After 40 minutes, a clear solution forms, which remains homogeneous when cooled to 25 ° C.

Example 14

To obtain the solvent, 0.67 g of benzyl alcohol and 0.33 g of 2-pyrrolidone are placed in a glass container and mixed by shaking the container for 5 s at 25 ° C. Then add 0.02 g of polyketone and heat the container to 180 ° C in order to intensify the dissolution process.

After 40 minutes, a clear solution forms, which remains homogeneous when cooled to 25 ° C.

Example 15

To obtain a solvent, 4.75 g of benzyl alcohol, 4.75 g of formamide and 4.75 g of ethylene carbonate are placed in a glass container and mixed by shaking the container for 15 s at 25 ° C. Then 0.75 g of polyketone is added to the solvent to obtain 5 wt. % polymer solution and heat the container to 180 ° C in order to intensify the dissolution process.

After 30 minutes, a clear solution forms, which forms a gel on cooling to 25 ° C. A sample is taken from the sample and its viscosity is measured (Table 1).

Example 16

To obtain a solvent, 9.5 g of benzyl alcohol, 4.75 g of cyclohexanol, and 4.75 g of N-methylacetamide are placed in a glass container and mixed by shaking the container for 15 s at 25 ° C. Then 1 g of polyamide is added to the solvent to obtain 5 wt. % polymer solution and the container is heated to 160 ° C in order to intensify the dissolution process.

After 30 min, a clear solution is formed, which remains homogeneous when cooled to 25 ° C. A sample is taken from the sample and its viscosity is measured (Table 1).

Example 17

To obtain a solvent, 4.75 g of benzyl alcohol and 4.75 g of N-methylacetamide are placed in a glass container and mixed by shaking the container for 10 s at 25 ° C. Then 0.25 g of polyamide and 0.25 g of polyketone are added to the solvent to obtain their combined 5 wt. % solution and heat the container to 180 ° C in order to intensify the dissolution process.

After 50 min, a clear solution is formed, which turns into a gel on cooling to 25 ° C. A sample is taken from the sample and its viscosity is measured (Table 1).

Thus, the solutions of polyamide and polyketone obtained according to this invention have a lower viscosity compared to solutions of the same polymers of the same concentration in known solvents such as m-cresol, hexafluoroisopropanol, trifluoroacetic acid and its mixture with methylene chloride (Table 1). This makes it possible, other things being equal, to use more concentrated spinning solutions for spinning, which makes it possible to obtain denser and, accordingly, strong fibers, as well as membrane materials suitable for filtering media with more finely dispersed contaminants.

Benzyl alcohol included in the mixed solvent is non-toxic and provides the possibility of choosing a co-solvent from a wide range of suitable non-toxic liquids with the desired phase transition temperatures, volatility and solubility for flexible regulation of the conditions for obtaining products - a specific molding method, temperature regime, composition of precipitation baths, etc.

A number of combinations of benzyl alcohol and co-solvent lead to the gelation of polymer solutions when they are cooled to room temperature, thus making it possible to obtain fibers by gel-spinning, and membranes - by the method of thermally initiated phase decomposition.

In addition, the invention opens up the possibility of processing polyamide and polyketone from their joint solutions, which makes it possible to obtain products from a new material - a mixture of polyamide and polyketone.

Claims (13)

1. A solvent for polyamide and / or polyketone, including a proton-donor solvent - alcohol, characterized in that it contains benzyl alcohol as an alcohol and additionally an organic co-solvent with a dispersion solubility parameter according to Hansen of at least 16.5 MPa ^0.5 at the following ratio of components, wt%. : benzyl alcohol 30-70 co-solvent rest 2. A method for processing a polymer by dissolving it in a solvent, shaping the resulting polymer solution and removing the solvent to obtain the target polymer product, characterized in that polyundecanamide and / or polydodecanamide and / or polyketone are used as the polymer, which is dissolved in the solvent according to claim . 1 with obtaining a polymer solution with the following ratio of components, wt%: polyamide and / or polyketone 0.1-30 solvent rest said molding is carried out by pouring a polymer solution onto a fluoroplastic substrate, removing the solvent by drying at a temperature of 140-160 ° C for 6 hours, and a thin-layer film is obtained as a polymer product. 3. A method for processing a polymer by dissolving it in a solvent, shaping the resulting polymer solution and removing the solvent to obtain the target polymer product, characterized in that polyundecanamide and / or polydodecanamide and / or polyketone are used as the polymer, which is dissolved in the solvent according to claim . 1 with obtaining a polymer solution with the following ratio of components, wt%: polyamide and / silt and polyketone 0.1-30 solvent rest said forming is carried out by placing a polymer solution between two films of polyethylene terephthalate with a polyester nonwoven fabric located between them and dipping into a precipitation bath with acetone, and a composite membrane is obtained as a polymer product. 4. The method according to claim 3, characterized in that the solvent is removed from the polymer solution by evaporation or extraction. 5. A method for processing a polymer by dissolving it in a solvent, shaping the resulting polymer solution and removing the solvent to obtain the desired polymer product, characterized in that polyundecanamide and / or polydodecanamide and / or polyketone are used as the polymer, which is dissolved in the solvent according to claim . 1 with obtaining a polymer solution with the following ratio of components, wt%: polyamide and / or polyketone 0.1-30 solvent rest said shaping is carried out by extrusion of a polymer solution into a precipitation bath with acetone through a forming device, and a fiber is obtained as a polymer product. 6. The method according to claim 5, characterized in that the solvent is removed from the polymer solution by evaporation or extraction.