RU2793765C1 - Method for obtaining treated glass fibres and a polymer composition reinforced by them = - Google Patents

Abstract

FIELD: polymer compositions.

SUBSTANCE: method for producing treated glass fibres and polymer compositions reinforced with them. Invention is intended for use as structural polymeric materials in additive technologies. The treatment agent is applied to glass fibres in a solution of4,4'diaminodiphenyl sulfone (DADPS) with a mass concentration of 0.1-0.7% in a mixture of organic solvents: acetone and isopropanol, and step-by-step increase in temperature is carried out in a nitrogen gas medium with simultaneous distillation of the solvent under the following modes: 20°C - 25 min, 30°C - 35 min, 45°C - 20 min, 55°C - 15 min, 65°C - 30 min, 85°C - 30 min. The number of components of the treated fibre corresponds to the ratio, in % by weight: fiberglass 96.5-99.5, DADPS 0.5-3.5. The polymer composition consists of 80% by weight of polyesterimide and 20% by weight of the specified treated glass fibre.

EFFECT: improving the compression strength of the polymer composition due to the introduction of a treatment component, which increases the wettability of the filler and increases the intermolecular interactions between the glass fibre and the polyesterimide matrix.

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Description

The invention relates to a method for producing sized glass fibers and polymer compositions reinforced by them with improved compressive strength values 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 compositions containing reinforcing glass fibers (glass fiber, GF) is the sizing of the glass fiber surface, 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. Thus, the USSR author's certificate for the invention No. 345249 (published on July 14, 1972, bull. No. 22) describes a method for finishing glass fibers 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 °C. The presence of aliphatic groups in the sizing 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.

A known composition for sizing glass fiber materials is a patent of Belarus No. 11045, 08.30.2008, IPC C03C 25/00. The composition contains 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 - 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 the patent of the Russian Federation 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 compressive strength of the polymer compositions.

The objective of the present invention is to develop a method for obtaining sized glass fibers, and polymer compositions reinforced with them, showing improved compressive strength values, based on a matrix polymer - polyetherimide (PEI), containing sized glass fibers (GF) as a reinforcing filler.

The task is achieved by the fact that the polymer composite material based on polyetherimide, reinforced with glass filler, is obtained by pre-treatment of glass fiber with a sizing component - 4,4'-diaminodiphenylsulfone (DADFS), formula:

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

is a polycondensation product of 1,3-diaminobenzene and 2,2'-bis[4(3,4-dicarboxyphenoxy)phenyl]propane dianhydride. The reduced viscosity is 0.62 dl/g, measured for a 0.5% solution in chloroform.

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

DADFS 0.5÷3.5 SW 99.5÷96.5

The amount of sized glass fiber in the polyesterimide composite is 20% by weight. 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'-diaminodiphenylsulfone in a mixture of isopropanol and 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. Used glass fiber brand RK-306 (IFI Technical Production), acetone and isopropanol, brand "HCh".

Below are examples illustrating the method of obtaining sized glass fibers using a sizing component.

Example 1. Obtaining finished SV with 0.5 wt.% DADPS.

In a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, 24.875 g (99.5 wt.%) SV with a fiber length of 3 mm are placed and a solution obtained by dissolving 0.125 g (0.5 wt.%) DADPS in 160 ml (50 wt.%) of a mixture of acetone and isopropanol (0.1% solution). Include a stirrer, nitrogen supply, and incubated for 25 minutes at a temperature of 20°C. After that, the contents of the flask are heated and acetone and isopropanol are distilled off according to the regime: 30°C - 35 minutes; 45°С - 20 min.; 55°С - 15 min.; 65°С - 30 min., 85°С - 30 min.

The dressed fiber is dried in an oven under vacuum at 87-88 °C for 2 hours.

Example 2. Obtaining finished SV with 1.0 wt.% DADFS.

Into a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, 24.75 g (99.0 wt.%) SV with a fiber length of 3 mm is placed and the solution obtained by dissolving 0.25 g (1.0 wt. %) DADFS in 160 ml (50 wt.%) of a mixture of acetone and isopropanol (0.2% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20°C. 45°С - 20 min.; 55°С - 15 min.; 65°С - 30 min., 85°С - 30 min.

The dressed fiber is dried in an oven under vacuum at 87-88 °C for 2 hours.

Example 3. Obtaining finished SV with 1.5 wt.% DADPS.

In a three-necked reaction flask equipped with a stirrer, a nitrogen gas supply system and a direct condenser, 24.625 g (98.5 wt.%) SV with a fiber length of 3 mm is placed and a solution obtained by dissolving 0.375 g (1.5 wt.%) DADPS in 160 ml (50 wt.%) of a mixture of acetone and isopropanol (0.3% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20°C. 45°С - 20 min.; 55°С - 15 min.; 65°С - 30 min., 85°С - 30 min.

The dressed fiber is dried in an oven under vacuum at 87-88 °C for 2 hours.

Example 4. Obtaining finished SV with 2.0 wt.% DADPS.

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 SV with a fiber length of 3 mm are placed and the solution obtained by dissolving 0.5 g (2.0 wt. %) DADFS in 160 ml (50 wt.%) of a mixture of acetone and isopropanol (0.4% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20°C. 45°С - 20 min.; 55°С - 15 min.; 65°С - 30 min., 85°С - 30 min.

The dressed fiber is dried in an oven under vacuum at 87-88 °C for 2 hours.

Example 5. Obtaining finished SV with 2.5 wt.% DADPS.

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.%) SV with a fiber length of 3 mm is placed and a solution obtained by dissolving 0.625 g (2.5 wt.%) DADPS in 160 ml (50 wt.%) of a mixture of acetone and isopropanol (0.5% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20°C. 45°С - 20 min.; 55°С - 15 min.; 65°С - 30 min., 85°С - 30 min.

The dressed fiber is dried in an oven under vacuum at 87-88 °C for 2 hours.

Example 6. Obtaining finished SV with 3.0 wt.% DADPS.

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 DM with a fiber length of 3 mm is placed and the solution obtained by dissolving 0.75 g (3.0 wt. %) DADFS in 160 ml (50 wt.%) of a mixture of acetone and isopropanol (0.6% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20°C. 45°С - 20 min.; 55°С - 15 min.; 65°С - 30 min., 85°С - 30 min.

The dressed fiber is dried in an oven under vacuum at 87-88 °C for 2 hours.

Example 7. Obtaining finished SV with 3.5 wt.% DADPS.

24.125 g (96.5 wt.%) SV 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 0.875 g (3.5 wt.%) DADPS in 160 ml (50 wt.%) of a mixture of acetone and isopropanol (0.7% solution). Turn on the stirrer, nitrogen supply, and incubate for 25 minutes at a temperature of 20°C. 45°С - 20 min.; 55°С - 15 min.; 65°С - 30 min., 85°С - 30 min.

The dressed fiber is dried in an oven under vacuum at 87-88 °C for 2 hours.

From the dressed SV and PEI, polymer compositions containing 20 wt.% of glass fibers dressed with 4,4'-diaminodiphenylsulfone were obtained.

Table 1 shows the compositions and compressive strength values of the composite materials of examples 1-7 treated with different amounts of sizing additive.

Table 1 Composition (wt.%) σ _compression ,
MPa PEI+20% DM non-prepared 324 According to example 1 328 According to example 2 333 According to example 3 337 According to example 4 339 According to example 5 346 According to example 6 345 According to example 7 345

where σ _compression is the compressive strength

As can be seen from the above data, polymer compositions based on polyesterimide, reinforced with glass fibers, containing sized GF (Nos. 1-7), exhibit higher compressive strengths compared to a composition containing untreated glass fibers.

The technical result of the invention is to improve the compressive strength of the created polymer composition due to the introduction of a sizing compound - 4,4'-diaminodiphenylsulfone, which increases the wettability of the filler and increases the boundary interactions between the filler and the polyesterimide matrix.

Claims (3)

1. A method for obtaining sizing glass fibers intended for the production of 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 87-88 ° C, characterized in that the sizing is applied from a solution 4,4'diaminodiphenylsulfone with a mass concentration of 0.1-0.7% in a mixture of organic solvents: 50 wt.% acetone and isopropanol each, and a stepwise increase in temperature is carried out in an atmosphere of nitrogen gas with simultaneous distillation of the solvent according to the regime: 20 ° C - 25 min, 30°C - 35 min, 45°C - 20 min, 55°C - 15 min, 65°C - 30 min and 85°C - 30 min, and the number of components of the finished fiber corresponds to the ratio, wt.%: glass fiber 96.5-99.5, 4,4'diaminodiphenylsulfone 0.5-3.5. 2. A polymer composition used for the production of structural products in additive technologies, containing a polymer matrix based on polyesterimide and a sized glass fiber, characterized in that the sized glass fiber according to claim 1 is used in the following ratio of components, wt.%: Polyetherimide 80 Finished glass fiber 20