CN103865024B - A kind of preparation method of super-elasticity urethane/montmorillonite nano complex - Google Patents

Abstract

The present invention relates to a kind of preparation method with super-elasticity urethane/montmorillonite nano complex, especially gentle (room temperature, manual stir and without the need to solvent) to prepare under condition.This method greatly reduces cost and energy consumption, simplifies production technique, and to be dispersed in the Sino-German polynite of polymkeric substance be lift-off structure, achieves real nano-dispersed.The mixture having the inventive method to prepare can be widely used in the fields such as light industry, chemical industry, building materials, aviation.

Description

A kind of preparation method of superelastic polyurethane/montmorillonite nanocomposite

technical field

The present invention relates to a kind of preparation method of polyurethane/montmorillonite nanocomposite with superelasticity, more specifically a kind of superelasticity prepared by pre-stripping method under mild (room temperature, manual stirring and no solvent) conditions A method for polyurethane/montmorillonite nanocomposites. The superelastic polyurethane/montmorillonite nanocomposite prepared by this pre-stripping method is widely used in light industry, chemical industry, building materials, aviation and other fields.

Background technique

Due to the nano-size effect, surface effect and strong interaction between nanoparticles and the matrix interface, polymer/montmorillonite nanocomposites have better physical and chemical properties than conventional composite materials with the same components, and have attracted widespread attention. . Polyurethane rubber is a synthetic material between plastic and rubber, which is formed by the reaction of polyisocyanate (eg, diisocyanate OCN-R-NCO) and polyol (eg, diol HO-R'-OH). Compared with polyester type and polyether type PU, the polyurethane elastomer made of hydroxyl-terminated polybutadiene liquid rubber as an oligomer not only ensures the good performance of polyurethane elastomer, but also has the characteristics similar to natural rubber. Such as air tightness, water resistance, etc., so that it has broad prospects in the fields of electronics industry, building materials, elastomers, epoxy resin toughening, preparation of adhesives and coatings. The high-performance research of polyurethane elastomers includes adjusting its molecular chain structure and adding inorganic fillers during the gradual polymerization process.

In the ChemMater magazine in 1998, an article about intercalated polyurethane/montmorillonite nanocomposites was first published (ZhenWang, ThomasJ.Pinnavaia.1998, 10: 3769-3771), by adding methylene diphenyl diisocyanate Intercalated polyurethane/montmorillonite nanocomposites were prepared by directly mixing bifunctional prepolymers with organic montmorillonite. Studies have shown that the addition of montmorillonite can enhance the mechanical properties of elastic polyurethane/montmorillonite nanocomposites. Subsequently, T.K.Chen et al. synthesized a new type of polyurethane/montmorillonite nanocomposite material by introducing polyhydroxycaprolactone/montmorillonite nanocomposite materials. The introduction of a small amount of polyhydroxycaprolactone/montmorillonite composite materials can make The comprehensive properties of polyurethane/montmorillonite nanocomposites are greatly improved (T.K.Chen, Y.I.Tien, K.H.Wei.Polymer, 2000, 41: 1345-1353). The research team also conducted a detailed study on the effect of montmorillonite on the intermolecular hydrogen bond and mechanical properties of composite materials, and found that the intermolecular hydrogen bond of polyurethane decreased with the increase of montmorillonite content, but when the mass fraction reached 5 %, there is no change, and the composite material with montmorillonite mass fraction of 1% has the best mechanical properties. (Y.I.Tien, WeiK.H. Polymer, 2001, 2: 3213-3221.)

Chinese patent CN1376739A discloses a preparation method of nano-montmorillonite and polyurethane composites, using in-situ polymerization mechanism to prepare nano-montmorillonite/polyurethane with higher mechanical properties without changing the existing operation process and synthesis route polyurethane compound. The raw material involved in this invention is nano-montmorillonite/polyether alcohol or polyester alcohol compound, not related to the liquid rubber used in the present invention; the preparation method is polymerized by bulk method or solution method, and the whole process requires high-speed stirring, ultrasonic oscillation, Solvent systems, etc., rather than room temperature, common manual stirring, solvent-free systems used in the present invention. Chinese patent CN1362450A reports a polyurethane/organoclay nanocomposite material and its preparation method. The method of monomer intercalation in-situ polymerization is used to make polyurethane and organoclay compatible at the molecular level, thereby obtaining high strength, good heat resistance and Polyurethane organoclay nanocomposites with good processability. The polyurethane organoclay nanocomposite material prepared by this invention is still an intercalation type composite, not the exfoliation type composite involved in the present invention, and does not involve the liquid rubber used in the present invention. Chinese patent CN1760301A discloses a liquid rubber adhesive containing nano-montmorillonite and its preparation method. By stirring and mixing hydroxyl-terminated polybutadiene liquid rubber, organic montmorillonite, toluene diisocyanate, and dibutyltin dilaurate, In vacuum degassing reaction in the system. The preparation method involved in the invention is prepared by adding all raw materials into the system and mixing them in one step, rather than the pre-stripping method involved in the invention. Chinese patent CN1487027A discloses a preparation method of a bulk polymer/exfoliated nanocomposite. The exfoliated composite is obtained by adding organic montmorillonite to a liquid or viscous polymer and grinding and dispersing in a cone mill or a colloid mill. The preparation method involved in the invention uses mechanical grinding to achieve uniform mixing of raw materials and peeling off of montmorillonite sheets, rather than the ordinary manual stirring and mixing involved in the invention. Chinese patent CN1523060A discloses an exfoliated polymer/montmorillonite nanocomposite material and a preparation method thereof. The polymer/montmorillonite nanocomposite material with an exfoliated structure is obtained by directly melting and mixing the polymer and organic montmorillonite. The extrusion melting intercalation method involved in this invention is not the common pre-stripping method under room temperature conditions involved in the present invention.

Contents of the invention

The object of the present invention is to provide a kind of preparation method that has superelastic polyurethane/montmorillonite nanocomposite, and this method can be realized by manual stirring at room temperature without using water and other organic solvents, greatly reducing cost and energy. consumption, which simplifies the production process, and the montmorillonite dispersed in the polymer has an exfoliated structure, realizing true nano-dispersion.

The preparation method of superelastic polyurethane/montmorillonite nanocomposite that the present invention relates to comprises the steps:

(1) In the water system, an organic montmorillonite is obtained;

(2) Mix the organic montmorillonite prepared in step (1) with the hydroxyl-terminated butadiene liquid rubber, stir evenly, and then place it in a constant temperature oven for several hours to obtain a stripped liquid rubber/organic montmorillonite nanocomposite gel;

(3) Add curing agent, chain extender, catalyst, etc. to the nanocomposite gel containing pre-exfoliated montmorillonite sheets prepared in step (2), pour them into a polytetrafluoro mold after uniform mixing, and vacuum bubble , cured for several hours, that is, a superelastic polyurethane/organic montmorillonite nanocomposite.

The advantages of the present invention are:

1. Do not use water and organic solvents. The method involved in the invention directly mixes the polymer and the montmorillonite, does not use water and organic solvents, avoids environmental pollution, and reduces production costs.

2. Mild preparation under normal temperature conditions. The preparation process involved in the present invention is simple, does not need high temperature and manual stirring, and has no special requirements for production equipment (that is, a mixer used in general industry can be realized), reduces energy consumption, and provides a wide range of industrial applications for liquid rubber. prospect.

3. The present invention directly disperses montmorillonite into exfoliated nano-sheets in advance, and this liquid rubber/montmorillonite nanocomposite containing pre-exfoliated nano-sheets can be easily obtained by directly adding a cross-linking agent for curing reaction. High performance polyurethane/montmorillonite nanocomposite. The method overcomes the self-aggregation of the montmorillonite sheets in the polyurethane matrix, is more conducive to the peeling and dispersion of the montmorillonite sheets, and is beneficial to the improvement of material properties.

4. The polyurethane/montmorillonite nanocomposite involved in the present invention has super-excellent elastic properties. The introduction of montmorillonite improves the elasticity-elongation at break and strength of the polyurethane material at the same time, which overcomes the inability of adding traditional inorganic fillers. It can enhance and toughen the material properties at the same time.

Description of drawings

Figure 1 X-ray diffraction spectrum of octadecyltrimethylammonium bromide modified montmorillonite

The X-ray diffraction spectrum of the liquid rubber/montmorillonite nanocomposite prepared in Fig. 2 embodiment 1

The X-ray diffraction spectrum of the liquid rubber/montmorillonite nanocomposite prepared in Fig. 3 embodiment 2

Figure 4 X-ray diffraction spectrum of dioctadecyldimethylammonium bromide modified montmorillonite

The X-ray diffraction spectrum of the liquid rubber/montmorillonite nanocomposite prepared in Fig. 5 embodiment 3

The transmission electron microscope figure of the liquid rubber/montmorillonite nanocomposite prepared in Fig. 6 embodiment 3

The X-ray diffraction spectrum of the liquid rubber/montmorillonite nanocomposite prepared in Fig. 7 embodiment 4

The X-ray diffraction spectrum of the liquid rubber/montmorillonite nanocomposite prepared in Fig. 8 embodiment 6

The transmission electron micrograph of the liquid rubber/montmorillonite nanocomposite prepared in Fig. 9 embodiment 6

detailed description

The technical solutions and effects of the present invention will be further described below in conjunction with the embodiments. However, the particular methodology, formulation and instructions employed are not limiting of the invention.

Example 1:

(1) Add 10 g of montmorillonite with a cation exchange capacity of 100 mmol/100 g, add 500 ml of water, disperse evenly, and stir at high speed for 1 hour to obtain a suspension a; dissolve 3.93 g of octadecyltrimethylammonium bromide in 50 ml Prepare solution b in water; heat the above suspension a to 80°C, add solution b dropwise, while stirring for 4 hours, naturally cool to room temperature, then filter with suction and wash with water (no bromide ion detected by 0.2% silver nitrate solution) , and organic montmorillonite can be obtained after drying. Its X-ray diffraction spectrum is shown in Fig. 1, and the diffraction peak near 2θ is 3.4° shows that the interlayer distance of organic montmorillonite is 2.55nm.

(2) 0.40g organic montmorillonite and 40g liquid hydroxyl-terminated polybutadiene rubber (HTPB, hydroxyl value 0.60mmol/g) were manually stirred at room temperature until mixed evenly, and placed in a constant temperature oven for 8 hours (optimal temperature 300-353K), and the liquid rubber/montmorillonite nanocomposite with an organic montmorillonite mass percentage content of 1% was prepared. The X-ray diffraction spectrum of the obtained nanocomposite is shown in Fig. 2, wherein the (001) surface diffraction peak of montmorillonite has basically completely disappeared, indicating that the montmorillonite sheet exists in the matrix of liquid rubber in an exfoliated state.

(3) At room temperature, mix 40.40g of exfoliated liquid rubber/montmorillonite nanocomposite, 1.9g of toluene diisocyanate and 0.2g of dibutyltin dilaurate and pour it into a polytetrafluoro mold, vacuum pumping, Then cured at 80° C. for 6 hours to obtain the polyurethane/montmorillonite nanocomposite.

Example 2:

(1) Add 10 g of montmorillonite with a cation exchange capacity of 100 mmol/100 g, add 500 ml of water, disperse evenly, and stir at high speed for 1 hour to obtain a suspension a; dissolve 3.93 g of octadecyltrimethylammonium bromide in 50 ml Prepare solution b in water; heat the above suspension a to 80°C, add solution b dropwise, and stir for 4 hours at the same time, naturally cool to room temperature, then suction filter, wash with water, and detect no bromide ion with 0.2% silver nitrate solution, Organic montmorillonite can be obtained after drying. Its X-ray diffraction spectrum is shown in Fig. 1, and the diffraction peak near 2θ is 3.4° shows that the interlayer distance of organic montmorillonite is 2.55nm.

(2) 1.24g organic montmorillonite and 40g liquid hydroxyl-terminated polybutadiene rubber (HTPB, hydroxyl value 0.60mmol/g) were manually stirred at room temperature until mixed evenly, and placed in a constant temperature oven for 8 hours (optimum temperature 300-353K), and the liquid rubber/montmorillonite nanocomposite with an organic montmorillonite mass percentage content of 3% was obtained. The X-ray diffraction spectrum of the obtained nanocomposite is shown in Fig. 3, wherein the (001) surface diffraction peak of montmorillonite has basically completely disappeared, indicating that the montmorillonite sheet exists in the matrix of liquid rubber in an exfoliated state.

(3) At room temperature, mix 41.24g of peeling liquid rubber/montmorillonite nanocomposite, 1.9g of toluene diisocyanate and 0.2g of dibutyltin dilaurate evenly and pour it into a polytetrafluoro mold, vacuum pumping, Then solidify at 80° C. for 6 hours to obtain the polyurethane/montmorillonite nanocomposite.

Example 3:

(1) Add 10g of montmorillonite with a cation exchange capacity of 100mmol/100g, add 500ml of water, disperse evenly, and stir at high speed for 1 hour to obtain a suspension a; dissolve 6.31g of dioctadecyldimethylammonium bromide in Prepare solution b in 50ml of water; heat the above suspension a to 80°C, add solution b dropwise, stir for 4 hours at the same time, cool to room temperature naturally, then filter with suction, wash with water, and detect no bromide ion with 0.2% silver nitrate solution , and organic montmorillonite can be obtained after drying. Its X-ray diffraction spectrum is shown in Figure 4, and the diffraction peak near 2.3° at 2θ indicates that the interlayer distance of organic montmorillonite is 3.57nm.

(2) 0.40g organic montmorillonite and 40g liquid hydroxyl-terminated polybutadiene rubber (HTPB, hydroxyl value 0.60mmol/g) were manually stirred at room temperature until mixed evenly, and placed in a constant temperature oven for 8 hours (optimal temperature 300-353K), and the liquid rubber/montmorillonite nanocomposite with an organic montmorillonite mass percentage content of 1% was prepared. The X-ray diffraction spectrum of the obtained nanocomposite is shown in Fig. 5, wherein the (001) plane diffraction peak of montmorillonite has almost completely disappeared, indicating that the montmorillonite sheet exists in the liquid rubber matrix in an exfoliated state. Transmission electron microscopy further illustrates that the montmorillonite sheets exist in the exfoliated state in the liquid rubber matrix, as shown in Figure 6.

(3) At room temperature, mix 40.40g of exfoliated liquid rubber/montmorillonite nanocomposite, 1.9g of toluene diisocyanate and 0.2g of dibutyltin dilaurate and pour it into a polytetrafluoro mold, vacuum pumping, Then cured at 80° C. for 6 hours to obtain the polyurethane/montmorillonite nanocomposite.

Example 4:

(1) Add 10g of montmorillonite with a cation exchange capacity of 100mmol/100g, add 500ml of water, disperse evenly, and stir at high speed for 1 hour to obtain a suspension a; dissolve 6.31g of dioctadecyldimethylammonium bromide in Prepare solution b in 50ml of water; heat the above suspension a to 80°C, add solution b dropwise, stir for 4 hours at the same time, cool to room temperature naturally, then filter with suction, wash with water, and detect no bromide ion with 0.2% silver nitrate solution , dried to obtain organic montmorillonite. Its X-ray diffraction spectrum is shown in Figure 4, and the diffraction peak near 2.3° at 2θ indicates that the interlayer distance of organic montmorillonite is 3.57nm.

(2) 1.24g organic montmorillonite and 40g liquid hydroxyl-terminated polybutadiene rubber (HTPB, hydroxyl value 0.60mmol/g) were manually stirred at room temperature until mixed evenly, and placed in a constant temperature oven for 8 hours (optimum temperature 300-353K), and the liquid rubber/montmorillonite nanocomposite with an organic montmorillonite mass percentage content of 3% was obtained. The X-ray diffraction spectrum of the obtained nanocomposite is shown in Fig. 7, in which the (001) plane diffraction peak of montmorillonite has almost completely disappeared, indicating that the montmorillonite sheet exists in the liquid rubber matrix in an exfoliated state.

(3) At room temperature, mix 41.24g of peeling liquid rubber/montmorillonite nanocomposite, 1.9g of toluene diisocyanate and 0.2g of dibutyltin dilaurate evenly and pour it into a polytetrafluoro mold, vacuum pumping, Then solidify at 80° C. for 6 hours to obtain polyurethane and montmorillonite nanocomposites.

Example 5:

(1) Add 10g of montmorillonite with a cation exchange capacity of 100mmol/100g, add 500ml of water, disperse evenly, and stir at high speed for 1 hour to obtain a suspension a; dissolve 6.31g of dioctadecyldimethylammonium bromide in Prepare solution b in 50ml of water; heat the above suspension a to 80°C, add solution b dropwise, stir for 4 hours at the same time, cool to room temperature naturally, then filter with suction, wash with water, and detect no bromide ion with 0.2% silver nitrate solution , dried to obtain organic montmorillonite. Its X-ray diffraction spectrum is shown in Figure 4, and the diffraction peak near 2.3° at 2θ indicates that the interlayer distance of organic montmorillonite is 3.57nm.

(2) 1.24g organic montmorillonite and 40g liquid hydroxyl-terminated polybutadiene rubber (HTPB, hydroxyl value 0.60mmol/g) were manually stirred at room temperature until mixed evenly, and placed in a constant temperature oven for 8 hours (optimum temperature 300-353K), and the liquid rubber/montmorillonite nanocomposite with an organic montmorillonite mass percentage content of 3% was obtained. The X-ray diffraction spectrum of the obtained nanocomposite is shown in Fig. 7, in which the (001) plane diffraction peak of montmorillonite has almost completely disappeared, indicating that the montmorillonite sheet exists in the liquid rubber matrix in an exfoliated state.

(3) At room temperature, mix 41.24g of exfoliated liquid rubber/montmorillonite nanocomposite, 2.3g of toluene diisocyanate and 0.2g of dibutyltin dilaurate and pour them into a polytetrafluoro mold, vacuum pumping, Then cured at 80° C. for 6 hours to obtain the polyurethane/montmorillonite nanocomposite.

Embodiment 6:

Other conditions are identical with embodiment 3, and the mixing of organic montmorillonite and liquid rubber is carried out in high-speed shearing machine, and shear velocity is 60r/min, and shearing time 10 minutes, see Fig. 8 through X-ray diffraction spectrum, wherein The (001) surface diffraction peak of montmorillonite has almost completely disappeared, indicating that the montmorillonite sheet exists in the liquid rubber matrix in a peeled state. Transmission electron microscopy further illustrates that the montmorillonite sheets exist in a peeled state in the liquid rubber matrix, as shown in Figure 9.

The mechanical property data that makes polyurethane/montmorillonite nanocomposite is listed in table 1, by the test data in table 1 as can be known, whether the mixing of organic montmorillonite and liquid rubber is hand stirring (embodiment 3) or common machinery Stirring (Example 6), the mechanical properties of the finally prepared polyurethane/montmorillonite nanocomposites have basically no difference. Therefore, the preparation method of the superelastic polyurethane/montmorillonite nanocomposite involved in this patent has the greatest advantage in that only manual stirring (room temperature, no solvent) is required in the preparation process to realize the optimization of material performance, which saves Low cost and green.

Table 1 Comparison of mechanical properties between polyurethane/montmorillonite nanocomposites and ordinary polyurethane

Note: (1) Isocyanate index R=NCO/OH: Indicates the ratio of the -NCO of toluene diisocyanate to the -OH of hydroxyl-terminated polybutadiene liquid rubber added to the system.

(2) The specification of the test sample is 20×5.0×1.0mm ³ , and there are no less than five samples of each material, and the mechanical performance indexes of the obtained materials are all average values.

Claims (1)

1. a preparation method for super-elasticity urethane/montmorillonite nano complex, comprises the following steps:

(1) by cation exchange capacity be the polynite 10g of 100mmol/100g, add water 500ml, and after being uniformly dispersed, high-speed stirring 1 hour, obtains suspension a; 6.31g DDA is dissolved in 50ml water, makes solution b; Above-mentioned suspension a is heated to 80 DEG C, drips solution b, stir 4 hours simultaneously, naturally cool to room temperature, then suction filtration, washing, detect to without bromide anion with 0.2% silver nitrate solution, after drying, can organo montmorillonite be obtained;

(2) by the Liquid Hydroxyl-Terminated Polybutadiene rubber of 0.40g organo montmorillonite and 40g hydroxyl value 0.60mmol/g, at room temperature manual being stirred to mixes, be placed in the constant temperature oven 8 hours of temperature 300-353K, obtained organo montmorillonite mass percentage is the fluid rubber/montmorillonite nano complex of 1%;

(3) at room temperature, pour in polytetrafluoro mould after 40.40g stripping-off liquid rubber/montmorillonite nano complex, 1.9g tolylene diisocyanate and 0.2g dibutyl tin laurate are mixed, vacuum takes out bubble, then in 80 DEG C of solidifications 6 hours, urethane/montmorillonite nano complex is obtained.