阅读说明：本技术 一种纳米TiO2环氧-聚氨酯复合材料的制备方法 (Preparation method of nano TiO2 epoxy-polyurethane composite material ) 是由 李阳 韩思宇 乔振扬 于 2020-07-13 设计创作，主要内容包括：本发明公开了一种纳米TiO2环氧-聚氨酯复合材料的制备方法,包括如下步骤：1、原料除水处理；2、纳米TiO2改性处理；3、纳米TiO2环氧-聚氨酯复合材料的制备。用二苯甲烷二异氰酸酯对纳米TiO2改性,并同时与其它羟基原料进行逐步聚合,然后引入环氧树脂进一步扩链改性,将纳米TiO2接枝到环氧-聚氨酯分子链上,制得纳米TiO2环氧-聚氨酯复合材料,经紫外、TEM、SEM、等分析手段表征制得的性能优异的纳米TiO2环氧-聚氨酯复合材料。制备的纳米TiO2环氧-聚氨酯复合材料与现有技术优点在于有较大的比表面积提供物理化学交联点使涂膜的表面憎水性和热稳定性,同时具有较宽的紫外吸收能力,使材料的表面产生强活性基团,使涂料具有抗菌和降解室内有机物的功能。(The invention discloses a preparation method of a nano TiO2 epoxy-polyurethane composite material, which comprises the following steps: 1. dehydrating the raw materials; 2. modifying nano TiO 2; 3. and (3) preparation of the nano TiO2 epoxy-polyurethane composite material. The nano TiO2 is modified by diphenylmethane diisocyanate, and is gradually polymerized with other hydroxyl raw materials, then epoxy resin is introduced for further chain extension modification, nano TiO2 is grafted to an epoxy-polyurethane molecular chain to prepare a nano TiO2 epoxy-polyurethane composite material, and the nano TiO2 epoxy-polyurethane composite material with excellent performance is prepared by characterization of ultraviolet, TEM, SEM and other analytical means. Compared with the prior art, the prepared nano TiO2 epoxy-polyurethane composite material has the advantages that the large specific surface area provides physical and chemical cross-linking points, so that the surface hydrophobicity and the thermal stability of a coating film are ensured, the ultraviolet absorption capacity is wide, strong active groups are generated on the surface of the material, and the coating has the functions of resisting bacteria and degrading indoor organic matters.)

1. Nano TiO (titanium dioxide)₂The preparation method of the epoxy-polyurethane composite material is characterized by comprising the following steps: the method comprises the following steps:

step 1: raw material dewatering treatment

a. Dewatering: dehydrating polyether polyol for 1-2 hours at the temperature of 110-120 ℃ and under the vacuum degree of 1.33MPa, placing the rest raw materials in an oven, keeping the temperature at 100-110 ℃, heating for 40-60 min, and placing the raw materials in a dryer for later use;

step 2: nano TiO2₂Modification treatment

b. Modification: weighing 0.2-0.4 g of white nano TiO₂Adding the mixture into 30-50 mL of acetone, dropwise adding the dispersed liquid into stirred diphenylmethane diisocyanate, heating to 70-80 ℃, dropwise adding 1-3 drops of dibutyltin dilaurate catalyst and 15-20 mL of polyether to react for 1-2 h, and uniformly dispersing the mixture for 6-8 h by using ultrasonic waves with the frequency of 40 KHz;

c. drying: placing the nano TiO2 prepared after the treatment in the step b into an oven, keeping the temperature at 100-110 ℃, and heating for 2-3 hours to prepare the modified nano TiO₂Putting into a dryer for standby;

and step 3: nano TiO2₂Preparation of epoxy-polyurethane composite material

d. Reaction: preparing 0.2-0.4 g of modified nano TiO prepared in step 2₂Adding 1-1.5 mL of diethylene glycol, 3-4 g of dimethylolpropionic acid and a proper amount of acetone, fully mixing the raw materials by using ultrasonic waves with the frequency of 40KHz, keeping the temperature for 1h, keeping the temperature at 50-70 ℃, dropwise adding 3-5 g of epoxy resin and 2-4 drops of dibutyltin dilaurate catalyst, reacting at the temperature of 50-70 ℃ for 2-3 h, and then reducing the temperature to 35-45 ℃;

e. milkAnd (3) conversion: adding 3-5 mL of triethylamine and 100-150 mL of deionized water into the solution after d treatment, stirring and emulsifying for 30-50 min, and removing the acetone solvent to obtain the nano TiO₂Epoxy-polyurethane composites.

2. A preparation method of a nano TiO2 epoxy-polyurethane composite material is characterized by comprising the following steps: a nano TiO2 epoxy-polyurethane composite material is described, which is prepared according to the steps of claim 1.

Technical Field

The invention relates to the technical field of materials, in particular to a preparation method of a nano TiO2 epoxy-polyurethane composite material.

Background

The nano particles are extremely small in size, about 1 to 100nm, and have the characteristics of unique small size effect, surface and interface effect, quantum size effect and the like. Meanwhile, the nano particles are small in particle size and high in specific surface activity, so that the nano particles are easy to agglomerate, the mechanical properties such as tensile strength, impact strength and the like of the polymer composite material are greatly limited, and the polymer composite material is subjected to certain modification treatment to prepare the composite material with excellent performance, so that the composite material meets the application requirements of the current market and has obvious defects at present.

The polyurethane coating has the characteristics of good wear resistance, good glossiness, good film forming property, low temperature resistance and the like, but the single polyurethane coating has many defects in the wood ware industry, such as low hardness, low solid content, poor water resistance, poor heat resistance and the like. Because the epoxy resin has the advantages of good bonding capability, electrical insulation, chemical resistance, high modulus, high strength, good adhesiveness and the like, the epoxy resin can be widely applied to industries such as electronics, buildings, automobiles, wood processing and the like, but has the defects of brittle quality, poor heat resistance, poor impact resistance and the like. The epoxy resin is compounded on the polyurethane material, so that the performance of the polyurethane can be greatly improved, and the application market of the epoxy modified polyurethane material is wider.

At present, the research finds that the added montmorillonite increases the crosslinking density of epoxy-polyurethane and the action of molecular chain hydrogen bond, so that the glass transition temperature of the polymer is increased by 3 percent. The modified cross-linked epoxy-polyurethane resin such as organic silicon, acrylic ester, organic fluorine and the like can further improve the mechanical property, water resistance, corrosion resistance and the like of epoxy-polyurethane, however, the water resistance and hardness of the epoxy modified polyurethane emulsion can obviously meet the application of most woodware coatings, and the functionalization of the epoxy-polyurethane emulsion coating through compounding functional nano TiO2 particles to an epoxy-polyurethane cross-linked network has very important significance.

Disclosure of Invention

The invention aims to provide a preparation method of a nano TiO2 epoxy-polyurethane composite material, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of a nano TiO2 epoxy-polyurethane composite material mainly comprises the following steps:

step 1: raw material dewatering treatment

a. Dewatering: dehydrating polyether polyol for 1-2 hours at the temperature of 110-120 ℃ and under the vacuum degree of 1.33MPa, placing the rest raw materials in an oven, keeping the temperature at 100-110 ℃, heating for 40-60 min, and placing the raw materials in a dryer for later use;

step 2: modification treatment of nano TiO2

b. Modification: weighing 0.2-0.4 g of white nano TiO2, adding the white nano TiO2 into 30-50 mL of acetone, dropwise adding the dispersed liquid into stirred diphenylmethane diisocyanate, heating to 70-80 ℃, dropwise adding 1-3 drops of dibutyltin dilaurate catalyst and 15-20 mL of polyether, reacting for 1-2 h, and uniformly dispersing the mixture for 6-8 h by using ultrasonic waves with the frequency of 40 KHz;

c. drying: placing the nano TiO2 prepared after the treatment in the step b into an oven, keeping the temperature at 100-110 ℃, heating for 2-3 hours to prepare modified nano TiO2, and placing the modified nano TiO2 into a dryer for later use;

and step 3: preparation of nano TiO2 epoxy-polyurethane composite material

d. Reaction: preparing 0.2-0.4 g of modified nano TiO2 prepared in the step 2, adding 1-1.5 mL of diethylene glycol, 3-4 g of dimethylolpropionic acid and a proper amount of acetone, fully mixing the materials by using ultrasonic waves with the frequency of 40KHz, keeping the temperature at 50-70 ℃ after keeping the temperature for 1h, dropwise adding 3-5 g of epoxy resin and 2-4 drops of dibutyltin dilaurate catalyst, reacting at the temperature of 50-70 ℃ for 2-3 h, and then reducing the temperature to 35-45 ℃;

e. emulsification: and d, adding 3-5 mL of triethylamine and 100-150 mL of deionized water into the solution after d treatment, stirring and emulsifying for 30-50 min, and removing the acetone solvent to obtain the nano TiO2 epoxy-polyurethane composite material.

A preparation method of a nano TiO2 epoxy-polyurethane composite material is characterized by comprising the following steps: a nano TiO2 epoxy-polyurethane composite material is described, which is prepared according to the steps of claim 1.

The invention discloses a preparation method of a nano TiO2 epoxy-polyurethane composite material, which comprises the steps of directly modifying nano TiO2 by using diphenylmethane diisocyanate, gradually polymerizing the modified nano TiO2 with other hydroxyl raw materials, introducing epoxy resin for further chain extension modification, and grafting nano TiO2 onto an epoxy-polyurethane molecular chain to prepare the TiO2 epoxy-polyurethane composite material with excellent performance.

Through the test and analysis of the TiO2 epoxy-polyurethane composite material, the prepared TiO2 epoxy-polyurethane composite material has larger specific surface area and provides physical and chemical cross-linking points, so that the surface hydrophobicity and the thermal stability of a coating film are ensured, meanwhile, the ultraviolet absorption capacity is wider, the absorbed ultraviolet energy can be absorbed, the surface of the material can generate strong active groups, and the coating has the functions of resisting bacteria and degrading indoor organic matters.

Drawings

FIG. 1 is an infrared absorption spectrum of epoxy resin and different composite materials prepared by the method of preparing a nano TiO2 epoxy-polyurethane composite material.

FIG. 2 is a particle size distribution diagram of an epoxy-polyurethane and nano TiO2 epoxy-polyurethane composite material prepared by the method for preparing a nano TiO2 epoxy-polyurethane composite material.

FIG. 3a is a SEM image of the cross section of an epoxy-polyurethane coating film of the preparation method of the nano TiO2 epoxy-polyurethane composite material.

FIG. 3b is an SEM image of the cross section of a nano TiO2 epoxy-polyurethane composite coating film prepared by the method for preparing the nano TiO2 epoxy-polyurethane composite material.

FIG. 4 is a transmission electron microscope image of a nano TiO2 epoxy-polyurethane composite material prepared by the method of the invention.

FIG. 5 is a thermal weight loss diagram of an epoxy-polyurethane and nano TiO2 epoxy-polyurethane composite coating film prepared by the method for preparing a nano TiO2 epoxy-polyurethane composite material.

Fig. 6a is a contact angle diagram of an epoxy-polyurethane coating film of a method for preparing a nano TiO2 epoxy-polyurethane composite material according to the present invention.

Fig. 6b is a contact angle diagram of a nano TiO2 epoxy-polyurethane composite coating film prepared by the method for preparing a nano TiO2 epoxy-polyurethane composite material.

Fig. 7 is a graph showing ultraviolet absorption curves of the nano TiO2, the nano TiO2 epoxy-polyurethane composite material and the epoxy-polyurethane in the preparation method of the nano TiO2 epoxy-polyurethane composite material.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The experimental medicine of the invention: nano-TiO 2 (self-made); epoxy resins (industrial grade, ba ling petrochemical); diphenylmethane diisocyanate (MDI) (industrial pure, bayer corporation); dimethylolpropionic acid (industrial pure, medium Anqing); acetone (analytically pure, Tianjin Yu Co.); triethylamine (analytically pure, Xilonga chemical company)

The experimental instrument of the invention: fourier transform infrared spectrometer (Perkin-Elmer, PE company, USA); uv-vis spectrophotometer (Lambda25, shanghai skpu); scanning electron microscope (JSM-6360LV, Japan Electron Co., Ltd.); an electric heating vacuum drying oven (model ZK-82B, Shanghai laboratory instruments Co.); particle size analyzer (Mastersizer3000Malvern Panalytical corporation); a transmission electron microscope (JEOL-3010 Japan Electron Co., Ltd.); ultrasonic cleaning machines (Shanghai ultrasonic Instrument works); integrated thermal analyzer (STA449F3/STA449F3 Germany Naichi)