CN111393657B - A kind of preparation method of organosilicon modified polyurethane - Google Patents

Abstract

The invention relates to the technical field of organic silicon, and aims to solve the problems existing in the existing synthesis of hyperbranched polyurethane, and provides a preparation method of organic silicon modified polyurethane, which takes hydroxyl-terminated hyperbranched aliphatic polyether-organic silicon block copolymer and hydroxyl-terminated polyether-organic silicon-polyether triblock copolymer as raw materials to react with polytetrahydrofuran, 1, 4-butanediol and diisocyanate to prepare an isocyanate-terminated component A and a hydroxyl-terminated component B, and then uniformly mixes the component A and the component B according to the molar ratio of isocyanate groups to hydroxyl groups of 6: 1-1: 9 to obtain a cured product, wherein the cured product has excellent alkali resistance and salt resistance, good thermal stability and better mechanical property.

Description

A kind of preparation method of organosilicon modified polyurethane

technical field

The invention relates to the technical field of organosilicon, in particular to a preparation method of an organosilicon modified polyurethane.

technical background

Polyurethane material is one of the fastest growing polymer materials. It has the characteristics of wear resistance, tear resistance, and good flexural flexibility. It can be made into products with different properties and has a wide range of uses. The structure of polyurethane is composed of soft segment and hard segment in the form of block, graft or interpenetrating network. The soft segment is usually polyether or polyester, which imparts flexibility and toughness to the polyurethane, and the hard segment is usually the polycondensate of diisocyanate and small molecular diol or diamine, which imparts strength and rigidity to the polyurethane. By adjusting the ratio of soft and hard segments and the structure of different polyols, materials with different properties can be obtained. Due to the introduction of hydrophilic groups in the molecular chain of water-based polyurethane, the water resistance of water-based polyurethane products is poorer than that of solvent resistance. Silicone has good high temperature resistance, heat aging properties and hydrophobicity. Modified polyurethane with silicone can improve the wet and dry adhesion properties, adhesion strength, water resistance, durability and tensile strength of polyurethane.

Hyperbranched polyurethanes are characterized by dendritic structure, low viscosity, versatility and easy film formation. Hyperbranched polyurethane has the common advantages of polyurethane and hyperbranched polymer, and is widely used in coatings, adhesives, inks and other fields. There are two main methods for preparing hyperbranched polyurethane, one is the reaction of hyperbranched polymers with terminal hydroxyl groups and isocyanate groups in isocyanates, and the other is the reaction of difunctional isocyanate molecules A2 with trifunctional hydroxyl or amino compound molecules B3. The existing hyperbranched polyurethane prepared by these two methods has the disadvantage of poor heat resistance, which limits its application. In order to overcome these shortcomings, Chinese invention patent CN201611040503.7 adopts polyfunctional alkoxysilane to react with polyurethane to obtain organosilicon-modified hyperbranched polyurethane with better heat resistance, but the organosilicon-modified polyurethane prepared by this method contains organic The silicon component is only the isolated segment after the hydrolysis of alkoxysilane is dispersed in the polymer molecule, and the organic silicon segment is short and the content is small, so it is difficult to give full play to the advantages of organic silicon.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the current synthesis of hyperbranched polyurethane, the present invention proposes a preparation method of organosilicon-modified polyurethane. The prepared organosilicon-modified polyurethane has excellent alkali resistance and salt resistance, good thermal stability, and relatively good mechanical properties.

The present invention is achieved through the following technical solutions: a preparation method of organosilicon modified polyurethane is the following steps:

(1) prepare isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component A;

(2) preparing a hydroxyl-terminated hyperbranched organosilicon modified polyurethane compound as component B;

(3) Then components A and B are mixed uniformly according to the molar ratio of isocyanate group to hydroxyl group of 6:1 to 1:9, and after vacuum removal of bubbles for 15 to 40 minutes, curing at 30 to 80 ° C for 1 to 12 hours to obtain a cured product , namely, silicone-modified polyurethane.

The silicone-modified polyurethane has a long silicone chain segment and high content, which can give full play to the advantages of silicone in temperature resistance, weather resistance, aging resistance, and hydrophobicity.

Step (1) Preparation method of isocyanate group-terminated hyperbranched organosilicon-modified polyurethane compound: hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, hydroxyl-terminated polyether-organosilicon-polyether tripolymer The block copolymer, polytetrahydrofuran, 1,4-butanediol and diisocyanate are used as raw materials, and the reaction is carried out in a reaction solvent under the action of a catalyst, and then the solvent is removed to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound ;

Among them, the isocyanate group in the diisocyanate and the hydroxyl-terminated hyperbranched aliphatic polyether block copolymer, the hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, polytetrahydrofuran and 1,4-butanedi The molar ratio of all hydroxyl groups in the polyol is 1.05:1-4:1, preferably 1.5:1-3:1. .

In step (2), the preparation method of the hydroxyl-terminated hyperbranched organosilicon modified polyurethane compound; the hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, the hydroxyl-terminated polyether-organosilicon-polyether Triblock copolymer, polytetrahydrofuran, 1,4-butanediol and diisocyanate are used as raw materials, react in a reaction solvent under the action of a catalyst, and then remove the solvent to obtain a hydroxyl-terminated hyperbranched organosilicon modified polyurethane compound ;

Among them, hydroxyl-terminated hyperbranched aliphatic polyether block copolymers, hydroxyl-terminated polyether-organosilicon-polyether triblock copolymers, polytetrahydrofuran and 1,4-butanediol, all hydroxyl and di- The molar ratio of the isocyanate groups in the isocyanate is 1.1:1 to 3:1, preferably 1.5:1 to 2:1.

In the process of preparing A and B, although the raw materials are basically the same, when preparing A, the isocyanate group is excessive, so that the end of the product is isocyanate group; when preparing B, the hydroxyl group is excessive, so that the end of the product is a hydroxyl group. The isocyanate group A and the hydroxyl group B are mixed according to a certain molar ratio, and curing can be achieved by the reaction of the isocyanate group and the hydroxyl group.

The hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymers described in steps (1) and (2) account for 1 to 15% of the total mass; hydroxyl-terminated polyether-organosilicon-polyether The triblock copolymer accounts for 5-30% of the total mass, 1,4-butanediol accounts for 1-8% of the total mass, and polytetrahydrofuran is the remaining mass; The organosilicon block copolymer accounts for 3-10% of the total mass; the hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer accounts for 5-20% of the total mass, and 1,4-butanediol accounts for 3-8% of the total mass, and polytetrahydrofuran is the remaining mass.

The above-mentioned total mass is hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, polytetrahydrofuran, 1,4-butanediol quality and.

In step (1) and step (2), the reaction solvent is selected from one or more of tetrahydrofuran, acetone, and N-methylpyrrolidone. Preferably, the reaction solvent is selected from one or more of tetrahydrofuran and acetone. The amount of solvent used in the preparation of component A and component B is diisocyanate, hydroxyl-terminated hyperbranched aliphatic polyether block copolymer, hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, polyether 20-200% of the total mass of tetrahydrofuran and 1,4-butanediol raw materials, preferably 50-100%.

The catalyst described in step (1) and step (2) is dibutyltin dilaurate. The amount of catalyst used is in the preparation of component A, in the preparation of component B, diisocyanate, hydroxyl-terminated hyperbranched aliphatic polyether block copolymer, and hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer. , 0.08% to 0.5% of the total mass of the raw materials of polytetrahydrofuran and 1,4-butanediol.

The diisocyanate in step (1) and step (2) is selected from 2,4-toluene diisocyanate and 2,6-toluene diisocyanate isomer mixture (TDI), diphenylmethane diisocyanate (MDI), 1 , 6-hexamethylene diisocyanate (HDI), one or more of isophorone diisocyanate (IPDI), preferably, the diisocyanate is one or more of TDI, HDI and IPDI.

The reaction conditions in step (1) and step (2) are 30°C～95°C for 1～6h, preferably, the synthesis reaction temperature is 40°C～70°C, and the reaction time is 2～5h.

In steps (1) and (2), the pressure is reduced to 60-120° C./130 mmHg to remove the solvent.

As preferably, the preparation method of the above-mentioned hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer is: the hydroxyl-terminated hyperbranched aliphatic polyether and n-butyllithium are in a molar ratio of hydroxyl to lithium atom of 1: 1. It is obtained by reacting in DMF solution to generate macromolecular initiator, then initiating ring-opening polymerization of hexamethylcyclotrisiloxane, and terminating the reaction with water.

Wherein, the preparation method of hydroxyl-terminated hyperbranched aliphatic polyether is as follows: take a clean and dry three-necked flask, under nitrogen protection, add 134.2g (1.0mol) trimethylolpropane, 73.5mL potassium methoxide-methanol solution (1.36 mol/L), after reacting at 80° C. for 1 h, 1555.7 g of glycidol (21.0 mol) was added dropwise, and after the dropwise addition was completed for about 6 h, the reaction was continued for 6 h. After the reaction was completed, methanol was added to dissolve the product, 36.5% hydrochloric acid was added dropwise for neutralization, and acetone was poured into the solution for precipitation. After repeating this purification twice, a transparent viscous liquid was obtained after vacuum drying at 70° C. for 24 hours, which was a hydroxyl-terminated hyperbranched aliphatic polyether. The reaction formula is shown in (I):

Preferably, the method for synthesizing the hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane is as follows: under nitrogen protection, take 3.52 g of hydroxyl-terminated hyperbranched aliphatic polyether (0.001 mol) into three Neck flask, 5～50mL DMSO and 10mL (2.5mol/L hexane solution) n-BuLi, stir at room temperature for 30～120min, then add 3.52g hydroxyl molar number (0.024mol hydroxyl group in the hydroxyl terminated hyperbranched aliphatic polyether) ) 1～100 times of hexamethylcyclotrisiloxane, react at 90～150℃ for 1～8h, cool down to 30～60℃, add 0.432g water, stir for 1～2h, filter, and decompress the filtrate to 150 ~170°C/130mmHg to remove low molecular weight and residual solvent to obtain hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane. The reaction structure is shown in (II):

Preferably, the preparation method of the hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer is as follows: combining a hydrogen-containing silicone oil with silicon hydrogen at both ends and a ring with hydroxyl at one end and allyl at the other end The ethylene oxide and propylene oxide copolymers are obtained through the hydrosilylation reaction catalyzed by platinum catalysts at 80 to 100° C. for 2 to 3 hours. The molecular structural formula of hydrogen-containing silicone oil with silicon hydrogen at both ends is HMe ₂ SiO(Me ₂ SiO) _m (MePhSiO) _n SiMe ₂ H, where m is an integer from 10 to 100, n is an integer from 0 to 50, and 0≤ n/m≤0.6. The molecular structural formula of a copolymer of ethylene oxide and propylene oxide with a hydroxyl group at one end and an allyl group at the other end is CH ₂ =CHCH ₂ O(CH ₂ CH ₂ O) _x (CH ₂ CH ₃ CHO) _y H, wherein x is a positive integer from 4 to 40, y is a positive integer from 0 to 20, and 0≤y/x≤0.5.

Wherein, the platinum catalyst is an isopropanol solution of H ₂ PtCl ₆ , a tetrahydrofuran solution of H ₂ PtCl ₆ , a platinum complex coordinated by methylvinylsiloxane, a platinum complex coordinated by diethyl phthalate One or more mixtures of the compounds, the platinum concentration is 2000-8000ppm, and the dosage is hydrogen-containing silicone oil whose two ends are silicon hydrogen and one end is hydroxyl group and the other end is allyl. 3 to 50 ppm of the total amount of propane copolymer.

A preparation method of organosilicon-modified polyurethane is the application of the prepared organosilicon-modified polyurethane in solvent-free paints, coatings and sealants. The invention uses hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer and hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer as raw materials, and is combined with polytetrahydrofuran, 1,4-butanediol The alcohol and diisocyanate are reacted to prepare the isocyanate-terminated component A and the hydroxyl-terminated component B, and then the A and B components are mixed uniformly according to the molar ratio of isocyanate group to hydroxyl group of 6:1 to 1:9, and vacuum removed. After 15 to 40 minutes of bubbles, curing at 30 to 80° C. for 1 to 12 hours to obtain a cured product. The organosilicon modified polyurethane has a long organosilicon chain segment and high content, which can give full play to the advantages of organosilicon in terms of temperature resistance, weather resistance, aging resistance, water repellency, etc. The cured product has excellent alkali resistance and salt resistance, good good thermal stability and good mechanical properties.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The organosilicon segment in the organosilicon modified polyurethane is long and the content is high, which can give full play to the advantages of organosilicon such as temperature resistance, weather resistance, aging resistance and water repellency;

(2) The cured product has excellent alkali resistance and salt resistance, good thermal stability, and good mechanical and mechanical properties.

Description of drawings

Fig. 1 is the FT-IR spectrum of hydroxyl-terminated hyperbranched aliphatic polyether;

Figure 2 is a ¹ H NMR spectrum of a hydroxyl terminated hyperbranched aliphatic polyether.

Detailed ways

The present invention will be described in further detail below through the examples and accompanying drawings. The raw materials used in the examples can be purchased from the market or prepared by conventional methods.

Test tensile strength and elongation at break: use a universal tensile machine to test the mechanical properties of the composite material, and test the tensile properties of the specimens according to the ASTMD-638 standard: prepare a standard dumbbell-shaped sample (length 80.0mm × width 12.5mm × thickness 4.0mm), carry out the tensile test at 1.0mm/min, measure at least 5 samples and take the average.

Thermal stability test: The temperature at which 5% of the thermal weight loss was measured by thermogravimetric analysis was used as the initial decomposition temperature to compare the thermal stability of the materials. Test conditions: Under nitrogen protection, the temperature was raised from room temperature to 800°C, and the heating rate was 10°C/min.

Performance test of acid, alkali and salt resistance: immerse the splines with a length of 20.0mm x width of 10mm x thickness of 4.0mm in 10wt% hydrochloric acid, 10wt% NaOH and 10wt% NaCl solution for 7 days to test their mass loss .

Preparation Example 1:

1. Preparation of hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane

(1) Preparation of hydroxyl terminated hyperbranched aliphatic polyether

Take a clean and dry three-necked flask, under nitrogen protection, add 134.2g (1.0mol) trimethylolpropane, 73.5mL potassium methoxide-methanol solution (1.36mol/L), react at 80 °C for 1h, add 1555.7 g glycidol (21.0mol), after the dropwise addition of about 6h was completed, the reaction was continued for 6h. After the reaction was completed, methanol was added to dissolve the product, 36.5% hydrochloric acid was added dropwise for neutralization, and acetone was poured into the solution for precipitation. After repeating this purification twice, a transparent viscous liquid was obtained after vacuum drying at 70° C. for 24 hours, which was a hydroxyl-terminated hyperbranched aliphatic polyether.

The FT-IR spectrum of the hydroxyl-terminated hyperbranched aliphatic polyether is shown in Figure 1, and the 1HNMR spectrum of the hydroxyl-terminated hyperbranched aliphatic polyether is shown in Figure 2.

(2) Under nitrogen protection, take 3.52g of hydroxyl-terminated hyperbranched aliphatic polyether (0.001mol) into a three-necked flask, 20ml DMSO and 10ml (2.5mol/L hexane solution) n-BuLi, stir at room temperature 30min, then add 266.4g of hexamethylcyclotrisiloxane (1.20mol) calculated according to the feeding ratio, react at 120°C for 4h, cool down to 60°C, add 0.432g of water, stir for 2h and filter the filtrate. Reduce the pressure to 170° C./130 mmHg to remove low molecular weight and residual solvent to obtain 245 g of hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane.

2. Preparation of hydroxyl-terminated polyether-silicon-polyether triblock copolymer

Take 102.2g hydrogen-containing silicone oil HMe ₂ SiO(Me ₂ SiO) ₁₂ SiMe ₂ H with silicon hydrogen at both ends, 82.0g ethylene oxide and propylene oxide copolymer CH ₂ with hydroxyl at one end and allyl at the other end ＝CHCH ₂ O(CH ₂ CH ₂ O) ₈ H was subjected to 0.30g of 8000ppm H ₂ PtCl ₆ solution in isopropanol to catalyze the hydrosilylation reaction to obtain 184.2g of hydroxyl-terminated polyether-organosilicon- Polyether triblock copolymer.

Example 1

(1) Take 5 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, 10 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer obtained in Preparation Example 1, and a polymer with a molecular weight of 2000. 38.0g of tetrahydrofuran, 0.530g of 1,4-butanediol and 11.0g of HDI, in 76.2g of reaction solvent acetone, under the catalysis of 0.0482g of dibutyltin dilaurate, react at 40°C for 4h, then reduce the pressure to 60°C /130mmHg to remove the solvent to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component A;

(2) Take 3 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymers, 20 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymers, and a molecular weight of 2000 obtained in Preparation Example 1 72g of tetrahydrofuran, 1.778g of 1,4-butanediol and 4.0g of HDI, in 73.2g of reaction solvent acetone, under the catalysis of 0.508g of dibutyltin dilaurate, react at 40°C for 4h, then reduce the pressure to 60°C/ Remove the solvent at 130 mmHg to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component B;

(3) 20gA and 10gB components are mixed uniformly, and after vacuum bubbles are removed for 30min, cured at 60° C. for 6h to obtain a silicone-modified polyurethane cured product.

The tensile strength of the cured product was 1.3MPa, the tensile strength at break was 97.0%, and the initial thermal decomposition temperature was 285°C. The mass loss of the cured product was 2.1% after immersing in a 10wt% NaOH aqueous solution for 7 days. 3.9% mass loss after days.

Example 2

(1) Take 6 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymers, 20 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymers, and a molecular weight of 2000 obtained in Preparation Example 1. 55g of tetrahydrofuran, 1.5g of 1,4-butanediol and 25.0g of TDI, in the reaction solvent 37.2g of N-methylpyrrolidone, under the catalysis of 0.93g of dibutyltin dilaurate, react at 90°C for 1h, under reduced pressure Remove the solvent at 120°C/130mmHg to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component A;

(2) Take 5 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, 20 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, and polytetrahydrofuran with molecular weight of 2000 obtained in Preparation Example 1 43.6g, 1.778g of 1,4-butanediol and 6.0g of TDI, in the reaction solvent N-methylpyrrolidone 74.2g, under the catalysis of 0.0764g of dibutyltin dilaurate, react at 90°C for 1h, under reduced pressure Remove the solvent at 120°C/130mmHg to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component B;

(3) 15gA and 10gB components are mixed uniformly, and after vacuum bubbles are removed for 30min, cured at 80° C. for 4h to obtain a silicone modified polyurethane cured product.

The tensile strength of the cured product was 1.8MPa, the tensile strength at break was 419.0%, and the initial thermal decomposition temperature was 295°C. The mass loss of the cured product was 1.5% after immersing in a 10wt% NaOH aqueous solution for 7 days. 0.78% mass loss after days.

Example 3

(1) Take 8 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymers, 15 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymers, and a molecular weight of 2000 obtained in Preparation Example 1. 50g of tetrahydrofuran, 1.5g of 1,4-butanediol and 36.0g of IPDI, in 80g of reaction solvent N-methylpyrrolidone, under the catalysis of 0.93g of dibutyltin dilaurate, react at 30°C for 6h, then reduce the pressure to Remove the solvent at 120°C/130mmHg to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component A;

(2) Take 8 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, 10 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, and polytetrahydrofuran with molecular weight of 2000 obtained in Preparation Example 1 100g, 1.778g of 1,4-butanediol and 7.0g of IPDI, in the reaction solvent N-methylpyrrolidone 120g, under the catalysis of 0.383g of dibutyltin dilaurate, react at 30°C for 6h, reduce the pressure to 120 ℃/130mmHg to remove the solvent to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component B;

(3) 20gA and 8gB components are mixed uniformly, and after vacuum removal of air bubbles for 30min, curing is performed at 80° C. for 4h to obtain a silicone modified polyurethane cured product.

The tensile strength of the cured product was 1.5MPa, the tensile strength at break was 363.0%, and the initial thermal decomposition temperature was 281.5°C. The mass loss of the cured product was 2.3% after immersing in 10wt% NaOH aqueous solution for 7 days. 0.55% mass loss after days.

Preparation Example 2

1. Preparation of hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane

(1) Preparation of hydroxyl terminated hyperbranched aliphatic polyether

Take a clean and dry three-necked flask, under nitrogen protection, add 134.2g (1.0mol) trimethylolpropane, 73.5mL potassium methoxide-methanol solution (1.36mol/L), react at 80 °C for 1h, add 1555.7 g glycidol (21.0mol), after the dropwise addition of about 6h was completed, the reaction was continued for 6h. After the reaction was completed, methanol was added to dissolve the product, 36.5% hydrochloric acid was added dropwise for neutralization, and acetone was poured into the solution for precipitation. After repeating this purification twice, a transparent viscous liquid was obtained after vacuum drying at 70° C. for 24 hours, which was a hydroxyl-terminated hyperbranched aliphatic polyether.

(2) Under nitrogen protection, take 3.52g of hydroxyl-terminated hyperbranched aliphatic polyether (0.001mol) into a three-necked flask, 50ml of DMSO and 10ml (2.5mol/L hexane solution) n-BuLi, and stir at room temperature 30min, then add 532.8g of hexamethylcyclotrisiloxane (2.40mol) calculated according to the feeding ratio, react at 140°C for 4h, cool down to 60°C, add 0.432g of water, stir for 2h and filter the filtrate. Reduce the pressure to 170° C./130 mmHg to remove low molecular weight and residual solvent to obtain 524 g of hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane.

2. Preparation of hydroxyl-terminated polyether-silicon-polyether triblock copolymer

Take 309.4 g of hydrogen-containing silicone oil HMe ₂ SiO (Me ₂ SiO) ₄₀ SiMe ₂ H with silicon hydrogen at both ends, 187.6 g of ethylene oxide and propylene oxide copolymer CH ₂ with hydroxyl at one end and allyl at the other end ＝CHCH ₂ O(CH ₂ CH ₂ O) ₂₀ H was subjected to 1.2g of 5000ppm methylvinylsiloxane-coordinated platinum complex catalyzed hydrosilylation reaction, and 497g of hydroxyl-terminated polymer was obtained in 90 for 2h. Ether-silicone-polyether triblock copolymer.

Example 4

(1) Take 5 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, 10 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, and polytetrahydrofuran with a molecular weight of 2000 obtained in Preparation Example 2 38.0g, 0.530g of 1,4-butanediol and 14.5g of TDI, in the reaction solvent tetrahydrofuran 78.2g, under the catalysis of 0.303g of dibutyltin dilaurate, react at 50°C for 3h, then reduce the pressure to 60°C/ Remove the solvent at 130 mmHg to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component A;

(2) Take 3 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, 20 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, and polytetrahydrofuran with molecular weight of 2000 obtained in Preparation Example 2 72g, 1.778g of 1,4-butanediol and 5.0g of TDI, in the reaction solvent tetrahydrofuran 74.2g, under the catalysis of 0.102g of dibutyltin dilaurate, react at 50°C for 3h, then reduce the pressure to 60°C/130mmHg Remove the solvent to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component B;

(3) 20gA and 10gB components are mixed uniformly, and after vacuum bubbles are removed for 30min, cured at 60° C. for 6h to obtain a silicone-modified polyurethane cured product.

The tensile strength of the cured product was 1.0 MPa, the tensile strength at break was 285.0%, and the initial thermal decomposition temperature was 295 °C. 1.4% mass loss after days.

Example 5

The 30gA and 10gB components in Example 4 were respectively mixed uniformly, and after the bubbles were removed in a vacuum for 30min, cured at 60°C for 6h to obtain a cured silicone-modified polyurethane.

The tensile strength of the cured product was 1.8MPa, the tensile strength at break was 324.0%, and the initial thermal decomposition temperature was 292.0°C. The mass loss of the cured product was 1.6% after soaking in 10wt% NaOH aqueous solution for 7 days. 0.85% mass loss after days.

Example 6

The 40gA and 10gB components in Example 4 were respectively mixed uniformly, and the bubbles were removed by vacuum for 40min, and then cured at 60°C for 5h to obtain a silicone-modified polyurethane cured product.

The tensile strength of the cured product was 1.4MPa, the tensile strength at break was 382.0%, and the initial thermal decomposition temperature was 283.0°C. 1.2% mass loss after days.

Preparation Example 3

1. Preparation of hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane

(1) Preparation of hydroxyl terminated hyperbranched aliphatic polyether

Take a clean and dry three-necked flask, under nitrogen protection, add 134.2g (1.0mol) trimethylolpropane, 73.5mL potassium methoxide-methanol solution (1.36mol/L), react at 80 °C for 1h, add 1555.7 g glycidol (21.0mol), after the dropwise addition of about 6h was completed, the reaction was continued for 6h. After the reaction was completed, methanol was added to dissolve the product, 36.5% hydrochloric acid was added dropwise for neutralization, and acetone was poured into the solution for precipitation. After repeating this purification twice, a transparent viscous liquid was obtained after vacuum drying at 70° C. for 24 hours, which was a hydroxyl-terminated hyperbranched aliphatic polyether.

(2) Under nitrogen protection, take 3.52g of hydroxyl-terminated hyperbranched aliphatic polyether (0.001mol) into a three-necked flask, 50ml of DMSO and 10ml (2.5mol/L hexane solution) n-BuLi, and stir at room temperature 30min, then add 1065.6g hexamethylcyclotrisiloxane (4.80mol) in the amount calculated according to the feeding ratio, react at 140°C for 4h, cool down to 60°C, add 0.432g water, stir for 2h, filter, and filter the filtrate. The pressure was reduced to 170° C./130 mmHg to remove low molecular weight and residual solvent to obtain 1045 g of hydroxyl-terminated hyperbranched aliphatic polyether block polydimethylsiloxane.

2. Preparation of hydroxyl-terminated polyether-silicon-polyether triblock copolymer

Take 143.34g of hydrogen-containing silicone oil HMe ₂ SiO(Me ₂ SiO) ₁₀₀ (MePhSiO) ₅₀ SiMe ₂ H with both ends of silicon hydrogen, 30.36g of ethylene oxide and propylene oxide with hydroxyl at one end and allyl at the other end Copolymer CH ₂ =CHCH ₂ O(CH ₂ CH ₂ O) ₂₀ (CH ₂ CH ₃ CHO) ₁₀ H via 0.6 g 3000 ppm of diethyl phthalate coordinated platinum complex catalyzed hydrosilylation reaction , 497g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer was obtained in 90 reaction for 2h.

Example 7

(1) Take 5 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, 10 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, and polytetrahydrofuran with a molecular weight of 2000 obtained in Preparation Example 3 38.0g, 1,4-butanediol 4.24g, HDI 4.5g and IPDI 15.4g, in the reaction solvent acetone 74.2g, under the catalysis of dibutyltin dilaurate 0.154g, react at 60°C for 3h, under reduced pressure Remove the solvent at 60°C/130mmHg to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component A;

(2) Take 3 g of hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, 20 g of hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, and polytetrahydrofuran with molecular weight of 2000 obtained in Preparation Example 3 72g, 1.778g of 1,4-butanediol, 2.0g of HDI and 4.0g of IPDI, in 71.2g of reaction solvent acetone, under the catalysis of 0.317g of dibutyltin dilaurate, react at 60°C for 3h, and then reduce the pressure to 60°C/130mmHg to remove the solvent to obtain an isocyanate group-terminated hyperbranched organosilicon modified polyurethane compound as component B;

(3) Mix 20gA and 10gB components uniformly, remove bubbles in vacuum for 30min, and cure at 60°C for 6h.

The tensile strength of the cured product was 2.0 MPa, the tensile strength at break was 380.0%, and the initial thermal decomposition temperature was 308.5 °C. After a few days, the mass loss was 0.45%, and the cured product of silicone-modified polyurethane was obtained.

Claims (10)

1. The preparation method of the organic silicon modified polyurethane is characterized by comprising the following steps:

(1) preparing an isocyanate-terminated hyperbranched organic silicon modified polyurethane compound as a component A;

the preparation method of the isocyanate group-terminated hyperbranched organic silicon modified polyurethane compound comprises the following steps: hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, polytetrahydrofuran, 1, 4-butanediol and diisocyanate are used as raw materials, and are reacted in a reaction solvent under the action of a catalyst, and then the solvent is removed to obtain an isocyanate-terminated hyperbranched organosilicon modified polyurethane compound;

(2) preparing a hydroxyl-terminated hyperbranched organic silicon modified polyurethane compound as a component B;

a preparation method of hydroxyl-terminated hyperbranched organic silicon modified polyurethane compound; reacting hydroxyl-terminated hyperbranched aliphatic polyether-organosilicon block copolymer, hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, polytetrahydrofuran, 1, 4-butanediol and diisocyanate as raw materials in a reaction solvent under the action of a catalyst, and then removing the solvent to obtain a hydroxyl-terminated hyperbranched organosilicon modified polyurethane compound;

(3) and then uniformly mixing the component A and the component B according to the molar ratio of isocyanate group to hydroxyl group of 6: 1-1: 9, removing bubbles in vacuum for 15-40 min, and curing at 30-80 ℃ for 1-12 h to obtain a cured substance, namely the organosilicon modified polyurethane.

2. The method for preparing the organosilicon modified polyurethane according to claim 1, wherein in the step (1), the molar ratio of the isocyanate groups in the diisocyanate to all the hydroxyl groups in the hydroxyl-terminated hyperbranched aliphatic polyether block copolymer, the hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, the polytetrahydrofuran and the 1, 4-butanediol is 1.05: 1-4: 1.

3. The method for preparing the organosilicon modified polyurethane according to claim 1, wherein the organosilicon modified polyurethane comprises the following steps: in the step (2), the mole ratio of all hydroxyl groups in the hydroxyl-terminated hyperbranched aliphatic polyether block copolymer, the hydroxyl-terminated polyether-organosilicon-polyether triblock copolymer, the polytetrahydrofuran and the 1, 4-butanediol to the isocyanate groups in the diisocyanate is 1.1: 1-3: 1.

4. The method for preparing the organosilicon-modified polyurethane according to claim 2 or 3, wherein the steps (1) and (2) are carried out in the step (1)

The hydroxyl-terminated hyperbranched aliphatic polyether block copolymer accounts for 1-15% of the total mass;

the hydroxyl-terminated polyether-organic silicon-polyether triblock copolymer accounts for 5-30% of the total mass of the raw materials, and the 1, 4-butanediol accounts for 1-8% of the total mass;

polytetrahydrofuran is the residual mass;

the total mass of the hydroxyl-terminated hyperbranched aliphatic polyether-organic silicon block copolymer, the hydroxyl-terminated polyether-organic silicon-polyether triblock copolymer, the polytetrahydrofuran and the 1, 4-butanediol is the sum of the mass.

5. The method for preparing the organosilicon modified polyurethane according to claim 2 or 3, wherein the reaction solvent is one or more selected from tetrahydrofuran, acetone, and N-methylpyrrolidone.

6. The preparation method of the organosilicon modified polyurethane according to claim 5, wherein the amount of the solvent used in the preparation of the component A and the component B is 20-200% of the total mass of the raw materials of diisocyanate, hydroxyl terminated hyperbranched aliphatic polyether block copolymer, hydroxyl terminated polyether-organosilicon-polyether triblock copolymer, polytetrahydrofuran and 1, 4-butanediol.

7. The method of claim 2 or 3, wherein the catalyst is dibutyl tin dilaurate.

8. The preparation method of the organosilicon modified polyurethane of claim 7, wherein the amount of the catalyst used is 0.08% -0.5% of the total mass of the raw materials of diisocyanate, hydroxyl terminated hyperbranched aliphatic polyether block copolymer, hydroxyl terminated polyether-organosilicon-polyether triblock copolymer, polytetrahydrofuran and 1, 4-butanediol in the preparation of the component A and the preparation of the component B respectively.

9. The preparation method of the organosilicon modified polyurethane according to claim 2 or 3, wherein the reaction conditions in step (1) and step (2) are 30 ℃ to 95 ℃ for 1 to 6 hours.

10. Use of the silicone-modified polyurethane prepared by the method of any one of claims 1 to 9 in paints, coatings, and sealants.

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