Because of the advantages of excellent friction resistance, mechanical property, low-temperature flexibility and the like, the polyurethane is widely applied to the industries of leather finishing, synthetic leather manufacturing, fabric coating, building road coating, adhesives, medical treatment and the like. With the continuous rising of the demand of people for high-performance, high-quality and high-environmental-protection ecological polyurethane, the demand that a single-performance polyurethane product cannot meet is met, and in recent years, functional polyurethane products such as fluorescence, color change, wave absorption, electromagnetic shielding and the like are favored by consumers.

The rhodamine mechaochromic fluorescent material is introduced into polyurethane, and obvious color change can occur before and after mechanical force stimulation, so that the rhodamine mechaochromic fluorescent material is expected to be used for pressure sensing in daily life of people, and has important significance for preparing the obvious color change material after mechanical force stimulation.

Disclosure of Invention

The invention aims to provide a preparation method of self-recoverable force-induced color-changing fluorescent water-based polyurethane, which has the advantages of lasting fluorescence characteristic, self-recovering force-induced color-changing property, environmental friendliness, simple and effective preparation method, simple process, easily-controlled operation condition and suitability for large-scale production and popularization and application.

The technical purpose of the invention is realized by the following technical scheme:

a preparation method of self-recoverable mechanochromic fluorescent water-based polyurethane comprises the following steps:

(1) preparation of hydroxy rhodamine

Dissolving rhodamine compounds in acetonitrile, adding monoethanolamine, controlling the temperature of the system to be constant, refluxing and stirring for a certain time, filtering after stirring to obtain a filter cake, fully washing the filter cake with deionized water until the color of the filtrate is clear, and drying the filter cake in a vacuum drying oven to obtain hydroxyl rhodamine;

(2) preparation of self-recoverable mechanochromic fluorescent water-based polyurethane

Adding polymer diol, diisocyanate, a small molecular weight diol chain extender and a catalyst which are dried in a vacuum oven with drying conditions overnight into a reaction container, reacting for 2-3h at 65-85 ℃ under the protection of continuous stirring and nitrogen atmosphere to obtain a prepolymer, adding an organic solvent in which a hydrophilic chain extender and the hydroxyl rhodamine prepared in the step (1) are dissolved into the obtained prepolymer, maintaining the system temperature at 65-85 ℃ and continuing to react for 2-3h, then adding triethylamine to neutralize the prepolymer, adding deionized water under the action of high shear force, and emulsifying at high speed to obtain the self-recoverable mechanochromic fluorescent water-based polyurethane;

wherein the dosage ratio of the components is as follows by weight: 0.1-0.5 part of hydroxyl rhodamine, 60-100 parts of polymer dihydric alcohol, 30-50 parts of diisocyanate, 2-5 parts of micromolecular dihydric alcohol chain extender, 0.01-0.2 part of catalyst, 5-20 parts of solvent, 5-7 parts of hydrophilic chain extender and 4-5 parts of triethylamine.

In the scheme, the rhodamine compound used in the step (1) is the rhodamine compound with the structural formula shown in the following figure:

in the above scheme, the polymer diol in step (2) is any one or combination of polypropylene glycol, polyethylene glycol or polytetrahydrofuran glycol with number average molecular weight of 1000-2000-.

In the above embodiment, the diisocyanate in the step (2) is any one of isophorone diisocyanate, 2, 4-toluene diisocyanate, 1, 6-hexyl diisocyanate, diphenylmethane diisocyanate, or 4,4' -dicyclohexylmethane diisocyanate.

In the above scheme, the small molecule diol chain extender in step (2) is any one of ethylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, or diethylene glycol.

In the scheme, the catalyst in the step (2) is any one of bismuth neodecanoate, bismuth laurate, bismuth isooctanoate, bismuth naphthenate, bis-dimethylaminoethylether or dimethylcyclohexylamine.

In the above scheme, the organic solvent in step (2) is any one of acetone, butanone N, N-dimethylformamide, N-dimethylacetamide, or N-methylpyrrolidone.

In the above scheme, the hydrophilic chain extender in step (2) is any one of dimethylolpropionic acid or dimethylolbutyric acid.

In the scheme, the drying conditions in the step (2) are 120 ℃ and 0.1 atm.

In the scheme, the specific route for modifying the rhodamine fluorescent compound is as follows:

the invention has the following innovation points and beneficial effects:

(1) hydroxyl and imino in the hydroxyl rhodamine provided by the invention can chemically react with isocyanic acid radical in isocyanate, and are permanently bonded with a polyurethane chain, so that the defects that an external addition type force-induced fluorescent material is poor in dispersibility and easy to aggregate in polyurethane are overcome, the fluorescence quenching phenomenon can be prevented, and the hydroxyl rhodamine has a lasting fluorescence characteristic;

(2) the self-recoverable force-induced color-changing fluorescent water-based polyurethane has the fluorescent characteristic of self-recovering force-induced color-changing property, emits strong yellow fluorescent light under ultraviolet rays and the like, changes the color of the fluorescent light after the action of mechanical force, and gradually self-recovers to the original yellow color after the action of the mechanical force disappears;

(3) the self-recoverable mechanochromic fluorescent water-based polyurethane provided by the invention takes water as a dispersion medium, can reduce the use of organic solvents and reduce environmental pollution, is environment-friendly, and has the advantages of simple and effective preparation method, simple process, easily-controlled operation conditions and suitability for large-scale production, popularization and application.

Detailed Description

The present invention is described in detail below by way of examples, and it should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention.

The rhodamine compounds used in the following examples are rhodamine compounds of which the structural formula is shown in the following figure:

example 1

(1) Preparation of hydroxy rhodamine

Dissolving 10g of rhodamine compound in 160mL of acetonitrile, adding 3.7mL of monoethanolamine, controlling the temperature of the system at 90 ℃, refluxing and stirring for 2h, filtering after stirring to obtain a filter cake, fully washing the filter cake with deionized water until the color of the filtrate is clear, and drying the filter cake in a vacuum drying oven to obtain the hydroxyl rhodamine.

Adding 100 parts of polypropylene glycol (120 ℃, 0.1atm vacuum oven drying overnight) with the average molecular weight of 2000, 50 parts of 4,4' -dicyclohexylmethane diisocyanate, 4 parts of 1, 4-butanediol and 0.2 part of bismuth laurate catalyst into a reaction container, heating to 85 ℃ under the protection of continuous stirring and nitrogen atmosphere, reacting for 2 hours to obtain a prepolymer, adding 20 parts of N, N-dimethylformamide-dissolved 7 parts of dimethylolpropionic acid and 0.5 part of the hydroxyl rhodamine prepared in the step (1), continuously reacting for 2 hours at 85 ℃, then adding 5 parts of triethylamine to neutralize the prepolymer, adding deionized water under the action of high shearing force, and emulsifying for 1 hour at high speed to obtain the self-recoverable mechanosensitive color-changing fluorescent water-based polyurethane.

Example 2

(1) Preparation of hydroxy rhodamine

Dissolving 10g of rhodamine compound in 160mL of acetonitrile, adding 3.7mL of 2-monoethanolamine, controlling the temperature of the system at 90 ℃, refluxing and stirring for 2h, filtering after stirring to obtain a filter cake, fully washing the filter cake with deionized water until the color of the filtrate is clear, and drying the filter cake in a vacuum drying oven to obtain the hydroxyl rhodamine.

Adding 20 parts of polyethylene glycol with the average molecular weight of 2000, 40 parts of polytetrahydrofuran glycol with the average molecular weight of 1000 (120 ℃, 0.1atm vacuum oven drying overnight), 30 parts of 2, 4-toluene diisocyanate, 2 parts of ethylene glycol and 0.01 part of bismuth neodecanoate catalyst into a reaction container, heating to 65 ℃ under the continuous stirring and nitrogen atmosphere protection to react for 2 hours to obtain a prepolymer, adding 5 parts of acetone-dissolved dimethylolbutyric acid and 0.1 part of hydroxyl rhodamine prepared in the step (1) into the obtained prepolymer, keeping at 65 ℃ for continuous reaction for 3 hours, then adding 4 parts of triethylamine to neutralize the prepolymer, adding deionized water under the action of high shearing force, and emulsifying at high speed for 1 hour to obtain the self-recoverable mechanochromic fluorescent water-based polyurethane.

Example 3

(1) Preparation of hydroxy rhodamine

Dissolving 10g of rhodamine compound in 160mL of acetonitrile, adding 3.7mL of 2-monoethanolamine, controlling the temperature of the system at 90 ℃, refluxing and stirring for 2h, filtering after stirring to obtain a filter cake, filtering, fully washing the filter cake with deionized water until the color of the filtrate is clear, and drying the filter cake in a vacuum drying oven to obtain the hydroxyl rhodamine.

Adding 80 parts of polytetrahydrofuran diol (120 ℃, 0.1atm vacuum oven drying overnight) with the average molecular weight of 2000, 40 parts of isophorone diisocyanate, 5 parts of diethylene glycol and 0.1 part of dimethylcyclohexylamine catalyst into a reaction container, heating to 80 ℃ under the protection of continuous stirring and nitrogen atmosphere, reacting for 3 hours to obtain a prepolymer, adding 15 parts of N, N-dimethylacetamide-dissolved 6 parts of dimethylolbutyric acid and 0.3 part of the hydroxyl rhodamine prepared in the step (1), keeping at 80 ℃, continuing to react for 2.5 hours, then adding 5 parts of triethylamine to neutralize the prepolymer, adding deionized water under the action of high shear force, and emulsifying at high speed for 1 hour to obtain the self-recoverable mechanosensitive color-changing fluorescent water-based polyurethane.

Example 4

(1) Preparation of hydroxy rhodamine

Adding 50 parts of polypropylene glycol with the average molecular weight of 2000, 20 parts of polyethylene glycol with the average molecular weight of 1000 (dried overnight in a vacuum oven at 120 ℃ under 0.1 atm), 40 parts of diphenylmethane diisocyanate, 2 parts of 1, 6-hexanediol and 0.05 part of bis-dimethylamino ethyl ether catalyst into a reaction container, heating to 65 ℃ under the protection of continuous stirring and nitrogen atmosphere, reacting for 2.5 hours to obtain a prepolymer, adding 10 parts of acetone-dissolved 6 parts of dimethylolpropionic acid and 0.2 part of the hydroxy rhodamine prepared in the step (1), keeping the temperature at 65 ℃ for continuous reaction for 3 hours, then adding 4.5 parts of triethylamine to neutralize the prepolymer, adding deionized water under the action of high shear force, and emulsifying for 1 hour at high speed to obtain the self-recoverable thermochromic fluorescent waterborne polyurethane.

In examples 1 to 4, isophorone diisocyanate, 2, 4-toluene diisocyanate, diphenylmethane diisocyanate, or 4,4' -dicyclohexylmethane diisocyanate can be replaced with 1, 6-hexyl diisocyanate; ethylene glycol, 1, 4-butanediol, 1, 6-hexanediol or diethylene glycol can be replaced by any one of 1, 3-propanediol or neopentyl glycol; the bismuth neodecanoate, the bismuth laurate, the bis-dimethylaminoethyl ether or the dimethylcyclohexylamine can be replaced by any one of bismuth isooctanoate or bismuth naphthenate; acetone, N-dimethylformamide or N, N-dimethylacetamide may be replaced by any of butanone or N-methylpyrrolidone.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

Translated fromChinese

1.一种可自恢复的力致变色荧光水基聚氨酯的制备方法，其特征在于，包括如下步骤：1. a preparation method of self-recoverable mechanochromic fluorescent water-based polyurethane, is characterized in that, comprises the steps:

(1)羟基罗丹明的制备(1) Preparation of hydroxyrhodamine

将罗丹明类化合物溶于乙腈，加入单乙醇胺，控制体系温度恒定，并回流搅拌一定时间，搅拌完成后过滤得到滤饼，用去离子水充分洗涤滤饼，直至滤液颜色澄清，将滤饼于真空干燥箱中烘干，得到羟基罗丹明；所用的罗丹明类化合物为结构式如下图所示的罗丹明类化合物：The rhodamine compounds were dissolved in acetonitrile, monoethanolamine was added, the temperature of the system was controlled to be constant, and the mixture was refluxed and stirred for a certain period of time. After the stirring was completed, a filter cake was obtained by filtration. Dry in a vacuum drying oven to obtain hydroxyrhodamine; the rhodamine compound used is the rhodamine compound whose structural formula is shown in the following figure:

(2)可自恢复的力致变色荧光水基聚氨酯的制备(2) Preparation of self-recoverable mechanochromic fluorescent water-based polyurethane

将在设置烘干条件的真空烘箱中烘干过夜的聚合物二元醇、二异氰酸酯、小分子二元醇扩链剂和催化剂加入反应容器，在持续搅拌和氮气气氛保护下，于65-85℃下反应2-3h制得预聚体，向所得预聚体中加入溶剂溶解有亲水扩链剂和步骤(1)制得的羟基罗丹明的有机溶剂，维持体系温度在65-85℃继续反应2-3h，然后加入三乙胺中和预聚体，在高剪切力作用下，加入去离子水，高速乳化后，即得可自恢复的力致变色荧光水基聚氨酯；The polymer diol, diisocyanate, small molecule diol chain extender and catalyst that were dried overnight in a vacuum oven with drying conditions were added to the reaction vessel, and under the protection of continuous stirring and nitrogen atmosphere, at 65-85 The prepolymer is obtained by reacting for 2-3 hours at ℃, and the organic solvent in which the hydrophilic chain extender and the hydroxyrhodamine obtained in step (1) are dissolved in a solvent is added to the obtained prepolymer, and the temperature of the system is maintained at 65-85 ℃ Continue the reaction for 2-3 hours, then add triethylamine to neutralize the prepolymer, add deionized water under the action of high shear force, and after high-speed emulsification, the self-recoverable mechanochromic fluorescent water-based polyurethane is obtained;

步骤(2)中所述的聚合物二元醇为数均分子量为1000-2000的聚丙二醇、聚乙二醇或聚四氢呋喃二醇中的任一种或其组合；The polymer diol described in the step (2) is any one or a combination thereof in polypropylene glycol, polyethylene glycol or polytetrahydrofuran diol having a number-average molecular weight of 1000-2000;

步骤(2)中所述的二异氰酸酯为异佛二酮二异氰酸酯、2,4-甲苯二异氰酸酯、1,6-己基二异氰酸酯、二苯基甲烷二异氰酸酯或4,4'-二环己基甲烷二异氰酸酯中的任一种；The diisocyanate described in step (2) is isophordione diisocyanate, 2,4-toluene diisocyanate, 1,6-hexyl diisocyanate, diphenylmethane diisocyanate or 4,4'-dicyclohexylmethane any of the diisocyanates;

步骤(2)中所述的小分子二元醇扩链剂为乙二醇、1,3-丙二醇、1,4-丁二醇、新戊二醇、1,6-己二醇、或一缩二乙二醇中的任一种；The small molecule diol chain extender described in step (2) is ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, or a any one of diethylene glycol;

步骤(2)中所述的催化剂为新癸酸铋、月桂酸铋、异辛酸铋、环烷酸铋、双二甲氨基乙基醚或二甲基环己胺中的任一种；The catalyst described in step (2) is any of bismuth neodecanoate, bismuth laurate, bismuth isooctanoate, bismuth naphthenate, bisdimethylaminoethyl ether or dimethylcyclohexylamine;

步骤(2)中所述的有机溶剂为丙酮、丁酮、 N,N-二甲基甲酰胺、N,N-二甲基乙酰胺或N-甲基吡咯烷酮中的任一种；The organic solvent described in step (2) is any one in acetone, butanone, N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone;

步骤(2)中所述的亲水扩链剂为二羟甲基丙酸或二羟甲基丁酸中的任一种；The hydrophilic chain extender described in step (2) is any in dimethylol propionic acid or dimethylol butyric acid;

步骤(2)中所述的烘干条件为120℃和0.1atm；其中，以重量份计算，上述各组分的用量比为：羟基罗丹明0.1-0.5份、聚合物二元醇60-100份、二异氰酸酯30-50份、小分子二元醇扩链剂2-5份、催化剂0.01-0.2份、溶剂5-20份、亲水扩链剂5-7份、三乙胺4-5份。The drying conditions described in the step (2) are 120° C. and 0.1 atm; wherein, calculated in parts by weight, the dosage ratios of the above components are: 0.1-0.5 parts of hydroxyrhodamine, 60-100 parts of polymer diols parts, 30-50 parts of diisocyanate, 2-5 parts of small molecular diol chain extender, 0.01-0.2 parts of catalyst, 5-20 parts of solvent, 5-7 parts of hydrophilic chain extender, 4-5 parts of triethylamine share.