RU2793761C1 - Method for obtaining finished glass fibers and a polyesterimide composite filled with them - Google Patents

Abstract

FIELD: glass fibers.

SUBSTANCE: method for obtaining dressed glass fibers, and polyesterimide composites filled with them with improved glass transition temperatures, intended as structural polymeric materials in additive techniques. The group of inventions can be used in the products manufacture using additive techniques. The method for obtaining dressed glass fibers includes applying a dressing composition from a solution followed by drying. Dressing composition contains 4,4' -dioxidiphenyl sulfon in acetone. A polyesterimide composite is also proposed.

EFFECT: increasing of the glass transition temperature of a polyesterimide composite containing a finished glass fiber.

2 cl, 1 tbl, 7 ex

Description

The invention relates to a method for producing sized glass fibers and polyesterimide composites filled with them with improved glass transition temperatures with inorganic, in particular glass fibers as fillers, and can be used for the production of special-purpose structural products in additive technologies.

One of the ways to improve the performance properties of polymer composites filled with glass fibers (glass fiber) is the application of a sizing agent to the surface of the glass fiber, which makes it possible to modify the structure of the interfacial layer and increase intermolecular adhesive interactions at the polymer-filler interface.

There are various types of sizing additives used in the creation of polymer composite materials. So, the USSR author's certificate for the invention No. 345249 (published on July 14, 1972, bull. No. 22) describes a method for finishing glass fiber with organosilicon phosphorus ethers. The main disadvantage of the proposed solution is the use of highly toxic xylene for applying a mixture of monomers to a glass canvas. To remove xylene, it is necessary to raise the temperature to 120 ^o C. The presence of aliphatic groups in the coupling agent structure will worsen the heat resistance and heat resistance of the composite.

Known composition for processing fiberglass - author's certificate of the USSR No. 1669883, IPC S03S 25/02, 1991. The composition contains epoxypropoxypropyltriethoxysilane, γ-aminopropyltriethoxysilane, glycerin or ethylene glycol, acetic acid and distilled water. This composition gives rigidity after sizing, which leads to the formation of a pile of destroyed filaments on the surface of the fiberglass. In the process of fiberglass processing by impregnation with epoxy, phenolic, melamine binders, relief, inhomogeneous areas are formed on the fabric in place of the destroyed filaments, which are difficult to process by pressing. In addition, this sizing has insufficiently high wetting rates of fiberglass.

Known composition for finishing glass fiber materials - patent of Belarus No. 11045, 08.30.2008, IPC S03S 25/00. The composition contains a polyfunctional silane brand Z-6224 - 0.5-2.0 wt. %, acetic or formic acid 0.5-2.0 wt. %, wetting agent sandocline PCJ 0.1-0.7 wt. %, the rest is distilled water. The composition is not suitable for high-temperature 3-D technologies, as it contains acids that will lead to the accumulation of ions, resulting in corrosion of metal surfaces and deterioration of the dielectric properties of composite materials.

In the next work - according to the patent of the Russian Federation No. 2201423, polymer compositions based on a polymer binder (sizing) and fiberglass or carbon filler were obtained. Previously, a binder - oligomer is obtained by reacting aromatic tetracarboxylic acid tetranitrile and aromatic bis-o-cyanamine at a temperature of 170-180°C. The binder is obtained in powder form. The main disadvantage of the above solution is the complexity of the binder synthesis process. An incomplete degree of conversion of monomers during synthesis can lead to the release of side low-molecular reaction products when the binder is combined with the filler at an elevated temperature, and, consequently, to the formation of voids in the composite material, which will lead to a deterioration in the strength characteristics of the material. In addition, powdered finishes may not cover the surface of the filler evenly enough.

The closest analogue is RF patent No. 2710559 “Method for obtaining finished glass fibers and composite materials based on them”. The paper proposes a method for obtaining sized glass fibers, which includes sizing glass fibers by applying a sizing material from a solution, followed by drying. As a sizing agent, a thermoplastic copolymer is used - copolyhydroxyether based on di(4-hydroxyphenyl)-sulfone, di(4-hydroxyphenyl)-propane and 3-chloro-1,2-epoxypropane. Composite materials are obtained from fiberglass finished in this way. The disadvantage of the solution is the relatively low values of the glass transition temperature of polymer composites.

The objective of the present invention is to obtain a polyesterimide-glass fiber composite with a sized glass fiber, showing improved values of the glass transition temperature, based on a matrix polymer - polyetherimide (PEI) containing sized glass fibers (GF) as a reinforcing filler.

The task is achieved by the fact that a polyesterimide composite material reinforced with a glass filler is obtained by pre-treatment of glass fiber (GF) with a sizing component - 4,4'-dioxydiphenylsulfone (DOPS), formula:

Matrix polymer - industrial polyesterimide (PEI) brand ULTEM-1010, formulas:

is a polycondensation product of 1,4-diaminobenzene and 2,2'-bis[4(3,4-dicarboxyphenoxy)phenyl]propane dianhydride. The reduced viscosity is 0.61 dl/g, measured for 0.5 wt. % solution in chloroform.

In this case, the following ratios (wt. %) of the components in the filler (DOPS + SV) are taken:

DOFS 0.25 ÷ 3.0 SW 99.75 ÷ 97.0

The amount of sized glass fiber in the polyesterimide composition is 20 wt. %. The treatment with such a sizing agent increases the wettability of the glass fiber with the matrix polyesterimide and makes it possible to heat-treat the product obtained repeatedly, if necessary, without changing the properties of the sizing composition.

Finished fibers are obtained by treating glass fiber with a sizing agent - a solution of 4,4'-dioxydiphenylsulfone in acetone. The polymer composite materials of the present invention are obtained by pre-mixing the polymer matrix and sized glass fiber using a high-speed homogenizer Multi function disintegrator VLM-40B. Then the polymer mixture is extruded using a laboratory twin-screw extruder with three heating zones at processing temperatures of 200 ^° C, 315 ^° C, 355 ^° C. Glass fiber of the brand RK-306 (IFI Technical Production), acetone, brand "HCh" were used.

Below are examples illustrating a method for obtaining sized glass fibers using a sizing component, and the sizing is applied from solutions with mass concentrations of 0.05-0.57 wt. % in an organic solvent.

Example 1. Obtaining finished SV with 0.25 wt. % DOPS.

24.9375 g (99.75 wt. %) of DM with a fiber length of 3 mm is placed in a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, and the solution obtained by dissolving 0.0625 g (0.25 wt. %) DOPS in 165 ml of acetone (0.05 wt. % solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20 °C. After that, the contents of the flask are heated and acetone is distilled off according to the regime: 25 ° C - 35 minutes; 35 °С - 30 min.; 45 °С - 25 min.; 55 °С - 20 min.; 65 °С - 20 min.

The dressed fiber is dried in a drying cabinet under vacuum at 69÷71 ^about C for 3 hours.

Example 2. Obtaining finished SV with 0.5 wt. % DOPS.

24.875 g (99.5 wt. %) of DM with a fiber length of 3 mm is placed in a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system, and a direct condenser, and a solution obtained by dissolving 0.125 g (0.5 wt. %) of DOPS in 165 ml of acetone (0.1% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20 °C. After that, the contents of the flask are heated and acetone is distilled off according to the regime: 25 ° C - 35 minutes; 35 °С - 30 min.; 45 °С - 25 min.; 55 °С - 20 min.; 65 °С - 20 min.

The dressed fiber is dried in a drying cabinet under vacuum at 69÷71 ^about C for 3 hours.

Example 3. Obtaining finished SV with 1.0 wt. % DOPS.

In a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, 24.75 g (99.0 wt. %) of SV with a fiber length of 3 mm are placed and the solution obtained by dissolving 0.25 g (1.0 wt. %) DOPS in 165 ml of acetone (0.19 wt. % solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20 °C. After that, the contents of the flask are heated and acetone is distilled off according to the regime: 25 ° C - 35 minutes; 35 °С - 30 min.; 45 °С - 25 min.; 55 °С - 20 min.; 65 °С - 20 min.

The dressed fiber is dried in a drying cabinet under vacuum at 69÷71 ^about C for 3 hours.

Example 4. Obtaining finished SV with 1.5 wt. % DOPS.

24.625 g (98.5 wt. %) of DM with a fiber length of 3 mm is placed into a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system, and a direct condenser, and a solution obtained by dissolving 0.375 g (1.5 wt. %) of DOPS in 165 ml of acetone (0.29 wt.% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20 °C. After that, the contents of the flask are heated and acetone is distilled off according to the regime: 25 ° C - 35 minutes; 35 °С - 30 min.; 45 °С - 25 min.; 55 °С - 20 min.; 65 °С - 20 min.

The finished fiber is dried in a drying oven under vacuum at 69÷71 ^about C for 3 hours.

Example 5. Obtaining finished SV with 2.0 wt. % DOPS.

In a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, 24.5 g (98.0 wt.%) of DM with a fiber length of 3 mm is placed and the solution obtained by dissolving 0.5 g (2.0 wt. %) DOPS in 165 ml of acetone (0.38 wt. % solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20 °C. After that, the contents of the flask are heated and acetone is distilled off according to the regime: 25 ° C - 35 minutes; 35 °С - 30 min.; 45 °С - 25 min.; 55 °С - 20 min.; 65 °С - 20 min.

The dressed fiber is dried in a drying cabinet under vacuum at 69÷71 ^about C for 3 hours.

Example 6. Obtaining finished SV with 2.5 wt. % DOPS.

In a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, 24.375 g (97.5 wt. %) of DM with a fiber length of 3 mm is placed and the solution obtained by dissolving 0.625 g (2.5 wt. %) of DOPS in 165 ml of acetone (0.48 wt.% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20 °C. After that, the contents of the flask are heated and acetone is distilled off according to the regime: 25 ° C - 35 minutes; 35 °С - 30 min.; 45 °С - 25 min.; 55 °С - 20 min.; 65 °С - 20 min.

The dressed fiber is dried in a drying cabinet under vacuum at 69÷71 ^about C for 3 hours.

Example 7. Obtaining finished SV with 3.0 wt. % DOPS.

In a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, 24.25 g (97.0 wt. %) of SV with a fiber length of 3 mm is placed and the solution obtained by dissolving 0.75 g (3.0 wt. %) DOPS in 165 ml of acetone (0.57 wt. % solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20 °C. After that, the contents of the flask are heated and acetone is distilled off according to the regime: 25 ° C - 35 minutes; 35 °С - 30 min.; 45 °С - 25 min.; 55 °С - 20 min.; 65 °С - 20 min.

The dressed fiber is dried in a drying cabinet under vacuum at 69÷71 ^about C for 3 hours.

Finished CB and PEI were used to obtain polymer composites containing 20 wt. % glass fibers finished with 4,4'-dioxydiphenylsulfone.

Table 1 presents the compositions of examples 1-7, as well as the glass transition temperatures of composites treated with various amounts of sizing additives.

Table 1

Composition (wt.%)
Glass transition temperature, ^o C PEI + 20% DM raw 214 Prototype 216 According to example 1 218 According to example 2 221 According to example 3 223 According to example 4 225 According to example 5 228 According to example 6 228 According to example 7 226

As can be seen from the above data, polymer composites based on polyesterimide filled with glass fibers containing sized GF (Nos. 1÷7) exhibit higher glass transition temperatures compared to a composite containing unfinished glass fibers and an analog.

The technical result of the invention is to improve the glass transition temperatures created by polyesterimide composites filled with glass fibers, due to the introduction of a sizing compound - 4,4'-dioxydiphenylsulfone, which increases the wettability of the filler and increases the boundary interactions between the filler and the polyesterimide matrix.

Claims (4)

1. A method for producing sizing glass fibers intended for structural products in additive technologies, based on sizing glass fibers by applying a sizing component from a solution, followed by drying in an oven under vacuum at 69-71 ° C, characterized in that the sizing is applied from solutions with mass concentrations of 0.05-0.57 wt. % in the organic solvent acetone and carry out a stepwise rise in temperature and distillation of the solvent according to the regime: 20°C - 25 min; 25°С - 35 min; 35°С - 30 min; 45°C - 25 min; 55°С - 20 min; 65°C - 20 min, and the quantitative ratio of the components corresponds, in mass. %.: 4,4'-dioxydiphenylsulfone (DOPS) 0.25 - 3.0 glass fiber 99.75 - 97.0 2. A polyesterimide composite used in the manufacture of structural products in additive technologies, containing a polymer matrix based on polyesterimide and a finished glass fiber, characterized in that a finished glass fiber is used, obtained by the method according to claim 1, and the quantitative ratio of the components in the composite material corresponds to, in mass %.: polyetherimide 80 finished glass fiber 20