Self-repairing organic fluorine-silicon modified polyurethane waterproof coating and preparation method thereof
Technical Field
The invention belongs to the technical field of waterproof materials, and particularly relates to a self-repairing organic fluorine-silicon modified polyurethane waterproof coating and a preparation method thereof.
Background
The self-repairing polyurethane material is a bionic intelligent material with high elasticity and self-repairing capability, and the self-repairing purpose is realized mainly by introducing a reversible valence covalent bond, such as a reversible disulfide bond, a reversible acylhydrazone bond and a Diels-Alder reaction, and under the stimulation of external conditions such as light, heat and the like, cracks generated by polyurethane are repaired through recombination of the covalent bond, so that the expansion of the cracks is avoided.
The organic fluorine-silicon material is a novel material which is organically synthesized by carrying out molecular structure design on organic fluorine and organic silicon materials, has the advantages of organic fluorine and organic silicon, and has excellent chemical properties such as high and low temperature resistance, super-hydrophobic and oleophobic property, photo-thermal resistance, weather resistance and the like.
In the prior art, although a synthesis method of various self-repairing polyurethane materials or a method of modifying polyurethane with organic fluorine silicon is disclosed, relevant documents or patents for further modifying polyurethane containing disulfide bonds by using organic fluorine silicon to enable the polyurethane to have functions of repeatable self-repairing and shape memory effect are not disclosed, for example, a patent with the application number of CN201910799259.X discloses a disulfide bond and hydrogen bond dual self-repairing polyurethane coating for invisible car clothes and a preparation method thereof.
In order to further improve the performances of the disulfide bond polyurethane such as hydrophobicity, oleophobicity, high and low temperature resistance, weather resistance, self-repairing and the like and expand the application range of the disulfide bond polyurethane, the invention utilizes the copolymerization of polytetramethylene ether glycol, perfluoropolyether glycol, isophorone diisocyanate, 4' -dithiodiphenylamine and fluorine-containing hydroxyl silicone oil to prepare the organic fluorine-silicon modified polyurethane waterproof coating with shape memory effect, self-repairing, anti-fouling and waterproof functions.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a self-repairing organic fluorine-silicon modified polyurethane waterproof coating and a preparation method thereof.
The technical scheme of the invention is summarized as follows:
the self-repairing organic fluorine-silicon modified polyurethane waterproof coating comprises the following raw materials in parts by mass:
preferably, the preparation method of the fluorine-containing hydroxyl silicone oil comprises the following steps: uniformly mixing trifluoropropylmethyl cyclotrisiloxane, tridecafluorooctyltriethoxysilane and hydroxyl silicone oil, then dropwise adding an ethylenediamine catalyst, introducing nitrogen, stirring and reacting at 100-115 ℃ for 3-8 h, and rotationally evaporating ethylenediamine at 120 ℃ to obtain the fluorine-containing hydroxyl silicone oil.
Preferably, the mass ratio of the trifluoropropylmethyl cyclotrisiloxane to the tridecafluorooctyltriethoxysilane to the hydroxyl silicone oil to the ethylenediamine catalyst is 1: (0.4-0.8): (1.8-3): (0.01-0.05).
The preparation method of the self-repairing organic fluorine-silicon modified polyurethane waterproof coating comprises the following steps:
s1: preparing a polyurethane prepolymer: mixing polytetramethylene ether glycol and perfluoropolyether glycol, dehydrating at 100-115 ℃ for 1-3 h in vacuum, cooling to 70-90 ℃, adding isophorone diisocyanate and dibutyltin dilaurate, and reacting for 3-6 h under the condition of heat preservation and stirring in a nitrogen atmosphere to obtain a polyurethane prepolymer;
s2: preparing organic fluorine-silicon modified polyurethane mixed liquid: dissolving 4,4' -dithiodiphenylamine and fluorine-containing vinyl silicone oil in tetrahydrofuran, adding a polyurethane prepolymer, and stirring and reacting at 60 ℃ for 3-6 hours in a nitrogen atmosphere to obtain a modified polyurethane mixed solution;
s3: preparing organic fluorine-silicon modified polyurethane waterproof paint: and (4) adding deionized water, tween 80, nano calcium carbonate and nano calcium hydroxy phosphate into the modified polyurethane mixed solution obtained in the step S2, and stirring and dispersing to obtain the organic fluorine-silicon modified polyurethane waterproof coating.
The invention has the beneficial effects that:
1. the invention combines the disulfide bond, the shape memory effect and the organic fluorine-silicon modification to prepare the modified polyurethane material with self-repairing, anti-fouling, waterproof and weather-proof properties, and uses-NH in 4,4' -dithiodiphenylamine2The addition polymerization reaction between the fluorine-containing hydroxyl silicone oil and-NCO introduces disulfide bonds, the self-repairing function of polyurethane is realized through repeated recombination of covalent bonds between sulfur atoms, the addition polymerization of-OH and-NCO in fluorine-containing hydroxyl silicone oil is utilized, C-F, Si-O bonds are introduced into the molecular chain of polyurethane, the performances of hydrophobicity, oleophobicity, high and low temperature resistance, weather resistance, chemical corrosion resistance and the like are obviously improved, and simultaneously, -NH2The water resistance and the mechanical property of the polyurethane are improved to a certain extent by a urea bond generated by the action of-NCO and an ester bond generated by the action of-OH and-NCO; in addition, the polyurethane with the shape memory effect is prepared by using polytetramethylene ether glycol, perfluoropolyether glycol and isophorone diisocyanate as raw materials, and the shape effect is used as an auxiliary restoring force to further accelerate the self-repairing efficiency of the material.
2. According to the invention, trifluoropropylmethyl cyclotrisiloxane and tridecafluorooctyltriethoxysilane are used for the first time to modify vinyl hydroxyl silicone oil, the surface tension of the hydroxyl silicone oil is reduced, and simultaneously, the function of a hydroxyl silicone oil coupling agent is endowed, so that nano calcium carbonate and nano calcium hydroxy phosphate are stably dispersed in polyurethane emulsion, and in addition, hydroxyl contained in the nano calcium hydroxy phosphate can react with unreacted-NCO in the polyurethane emulsion and then grafted on a polyurethane molecular chain, and the stability of the coating is further improved.
Drawings
FIG. 1 is a flow chart of a preparation method of the self-repairing organic fluorine-silicon modified polyurethane waterproof coating.
Detailed Description
The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.
Example 1
The preparation method of the self-repairing organic fluorine-silicon modified polyurethane waterproof coating comprises the following steps:
s1: preparing fluorine-containing hydroxyl silicone oil: uniformly mixing trifluoropropylmethyl cyclotrisiloxane, tridecafluorooctyltriethoxysilane and hydroxyl silicone oil, dropwise adding an ethylenediamine catalyst, introducing nitrogen, stirring at 100 ℃ for reaction for 3 hours, and rotationally evaporating ethylenediamine at 120 ℃ to obtain the fluorine-containing hydroxyl silicone oil; the mass ratio of the trifluoropropylmethyl cyclotrisiloxane to the tridecafluorooctyltriethoxysilane to the hydroxyl silicone oil to the ethylenediamine catalyst is 1: 0.4: 1.8: 0.01;
s2: preparing materials: weighing 60 parts of polytetramethylene ether glycol, 15 parts of perfluoropolyether glycol, 40 parts of isophorone diisocyanate, 20 parts of 4,4' -dithio diphenylamine, 20 parts of fluorine-containing hydroxyl silicone oil, 30 parts of tetrahydrofuran, 0.8 part of dibutyltin dilaurate, 802 parts of tween, 15 parts of nano calcium carbonate, 5 parts of nano calcium hydroxy phosphate and 10-20 parts of deionized water according to parts by mass;
s3: preparing a polyurethane prepolymer: mixing polytetramethylene ether glycol and perfluoropolyether glycol, dehydrating at 100 ℃ for 1.5h in vacuum, cooling to 70 ℃, adding isophorone diisocyanate and dibutyltin dilaurate, and reacting for 3h under the condition of nitrogen gas and stirring at a constant temperature to obtain a polyurethane prepolymer;
s4: preparing organic fluorine-silicon modified polyurethane mixed liquid: dissolving 4,4' -dithiodiphenylamine and fluorine-containing vinyl silicone oil in tetrahydrofuran, adding a polyurethane prepolymer, and stirring and reacting at 60 ℃ for 3 hours under a nitrogen atmosphere to obtain a modified polyurethane mixed solution;
s5: preparing organic fluorine-silicon modified polyurethane waterproof paint: and (4) adding deionized water, tween 80, nano calcium carbonate and nano calcium hydroxy phosphate into the modified polyurethane mixed solution obtained in the step S4, and stirring and dispersing to obtain the organic fluorine-silicon modified polyurethane waterproof coating.
Example 2
The preparation method of the self-repairing organic fluorine-silicon modified polyurethane waterproof coating comprises the following steps:
s1: preparing fluorine-containing hydroxyl silicone oil: uniformly mixing trifluoropropylmethyl cyclotrisiloxane, tridecafluorooctyltriethoxysilane and hydroxyl silicone oil, dropwise adding an ethylenediamine catalyst, introducing nitrogen, stirring at 110 ℃ for 5 hours to react, and rotationally evaporating ethylenediamine at 120 ℃ to obtain the fluorine-containing hydroxyl silicone oil; the mass ratio of the trifluoropropylmethyl cyclotrisiloxane to the tridecafluorooctyltriethoxysilane to the hydroxyl silicone oil to the ethylenediamine catalyst is 1: 0.6: 2.4: 0.03;
s2: preparing materials: weighing 70 parts of polytetramethylene ether glycol, 25 parts of perfluoropolyether glycol, 50 parts of isophorone diisocyanate, 27 parts of 4,4' -dithio diphenylamine, 25 parts of fluorine-containing hydroxyl silicone oil, 35 parts of tetrahydrofuran, 1.5 parts of dibutyltin dilaurate, 802.5 parts of tween, 18 parts of nano calcium carbonate, 8 parts of nano calcium hydroxy phosphate and 15 parts of deionized water according to parts by mass;
s3: preparing a polyurethane prepolymer: mixing polytetramethylene ether glycol and perfluoropolyether glycol, dehydrating at 110 ℃ for 2h in vacuum, cooling to 80 ℃, adding isophorone diisocyanate and dibutyltin dilaurate, and reacting for 5h under the condition of heat preservation and stirring in a nitrogen atmosphere to obtain a polyurethane prepolymer;
s4: preparing organic fluorine-silicon modified polyurethane mixed liquid: dissolving 4,4' -dithiodiphenylamine and fluorine-containing vinyl silicone oil in tetrahydrofuran, adding a polyurethane prepolymer, and stirring and reacting at 60 ℃ for 5 hours under a nitrogen atmosphere to obtain a modified polyurethane mixed solution;
s5: preparing organic fluorine-silicon modified polyurethane waterproof paint: and (4) adding deionized water, tween 80, nano calcium carbonate and nano calcium hydroxy phosphate into the modified polyurethane mixed solution obtained in the step S4, and stirring and dispersing to obtain the organic fluorine-silicon modified polyurethane waterproof coating.
Example 3
The preparation method of the self-repairing organic fluorine-silicon modified polyurethane waterproof coating comprises the following steps:
s1: preparing fluorine-containing hydroxyl silicone oil: uniformly mixing trifluoropropylmethyl cyclotrisiloxane, tridecafluorooctyltriethoxysilane and hydroxyl silicone oil, dropwise adding an ethylenediamine catalyst, introducing nitrogen, stirring at 115 ℃ for reacting for 8 hours, and rotationally evaporating ethylenediamine at 120 ℃ to obtain the fluorine-containing hydroxyl silicone oil; the mass ratio of the trifluoropropylmethyl cyclotrisiloxane to the tridecafluorooctyltriethoxysilane to the hydroxyl silicone oil to the ethylenediamine catalyst is 1: 0.8: 3: 0.05;
s2: preparing materials: weighing 80 parts of polytetramethylene ether glycol, 30 parts of perfluoropolyether glycol, 60 parts of isophorone diisocyanate, 35 parts of 4,4' -dithio diphenylamine, 30 parts of fluorine-containing hydroxyl silicone oil, 40 parts of tetrahydrofuran, 2 parts of dibutyltin dilaurate, 803 parts of tween, 20 parts of nano calcium carbonate, 10 parts of nano calcium hydroxy phosphate and 20 parts of deionized water according to parts by mass;
s3: preparing a polyurethane prepolymer: mixing polytetramethylene ether glycol and perfluoropolyether glycol, dehydrating at 115 ℃ for 3h in vacuum, cooling to 90 ℃, adding isophorone diisocyanate and dibutyltin dilaurate, and reacting for 6h under the condition of heat preservation and stirring in a nitrogen atmosphere to obtain a polyurethane prepolymer;
s4: preparing organic fluorine-silicon modified polyurethane mixed liquid: dissolving 4,4' -dithiodiphenylamine and fluorine-containing vinyl silicone oil in tetrahydrofuran, adding a polyurethane prepolymer, and stirring and reacting at 60 ℃ for 6 hours under a nitrogen atmosphere to obtain a modified polyurethane mixed solution;
s5: preparing organic fluorine-silicon modified polyurethane waterproof paint: and (4) adding deionized water, tween 80, nano calcium carbonate and nano calcium hydroxy phosphate into the modified polyurethane mixed solution obtained in the step S4, and stirring and dispersing to obtain the organic fluorine-silicon modified polyurethane waterproof coating.
Comparative example 1
The same as in example 1, except that: the preparation process does not add fluorine-containing hydroxyl silicone oil and perfluoropolyether diol.
Comparative example 2
The same as in example 1, except that: 4,4' -dithiodiphenylamine is not added in the preparation process.
Uniformly coating the polyurethane waterproof coatings prepared in the examples 1-3 and the comparative examples 1-2 on the surface of a glass substrate, drying and curing, and measuring the water contact angle theta of the surface of a coating film by using a JC2000C type dynamic contact angle measuring instrument; rubbing the surface of the coating film by using a 15N scraping assembly to ensure that the surface of the coating film is completely scraped, taking the area of the coating film as an initial scratch damage area S1, performing heat treatment at 100 ℃ for 2 hours, measuring the treated scratch damage area S2, and calculating self-repairing efficiency according to a formula of 100% × (S1-S2)/S1; and further measured according to GBT19250-2013 polyurethane waterproof paint, the test results are shown in the following table:
as can be seen from the above table, the modified polyurethane material capable of self-repairing, anti-fouling, waterproof and weather-resistant is prepared by combining disulfide bond, shape memory effect and organic fluorine-silicon modification, and the-NH in 4,4' -dithiodiphenylamine is utilized2The addition polymerization reaction between the fluorine-containing hydroxyl silicone oil and-NCO introduces disulfide bonds, the self-repairing function of polyurethane is realized through repeated recombination of covalent bonds between sulfur atoms, the addition polymerization of-OH and-NCO in fluorine-containing hydroxyl silicone oil is utilized, C-F, Si-O bonds are introduced into the molecular chain of polyurethane, the performances of hydrophobicity, oleophobicity, high and low temperature resistance, weather resistance, chemical corrosion resistance and the like are obviously improved, and simultaneously, -NH2The water resistance and the mechanical property of the polyurethane are improved to a certain extent by a urea bond generated by the action of-NCO and an ester bond generated by the action of-OH and-NCO.
While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are fully applicable in all kinds of fields of application of the invention, and further modifications may readily be effected by those skilled in the art, so that the invention is not limited to the specific details without departing from the general concept defined by the claims and the scope of equivalents.