Summary of the invention
The invention provides a kind of preparation method of chitin whisker modified aqueous polyurethane, it is characterized in that, in turn include the following steps:
1) by polyisocyanates and raw material polyester polyol or/and polyether glycol stirs through mixing, obtain polyurethane prepolymer after the reaction;
2) add small molecule chain extender in the polyurethane prepolymer that in step 1), obtains, stirring reaction, and use the acetone viscosity reduction;
3) with step 2) reaction product that obtains is cooled to below 40 ℃, adds neutralization reagent then, the adjusting pH value is 6-8, in and after 5-10 minute, water-dispersion on the rocks again, aqueous polyurethane emulsion; Add the chitin whisker blend in described aqueous polyurethane emulsion, vacuumize then and remove acetone, the mass percent of control solid content is 5-40%, gets described chitin whisker modified aqueous polyurethane.
In the step 1) of the present invention, or/and polyether glycol when mixing, its mass percent is: polyisocyanates is 65-90% when described polyisocyanates and described polyester polyol, and polyester polyol is or/and polyether glycol is 10-35%; Wherein, when described polyisocyanates mixed with the pure and mild polyether glycol of described polyester polyols, described polyester polyol and polyether glycol mass percent between the two was any proportioning.
In the step 1) of the present invention, mixing the temperature that stirs is 70-90 ℃, and the reaction times is 2-3 hour.
Step 2 of the present invention) carry out under 70-90 ℃, the add-on of described small molecule chain extender is the 10-50% of polyisocyanates quality, and the stirring reaction time is 1-2 hour.Described step 2) add-on of acetone is that polyisocyanates, polyester polyol are or/and the 10-30% of polyether glycol and small molecule chain extender three total mass in.
In the step 3) of the present invention, the add-on of described chitin whisker is that polyisocyanates, polyester polyol are or/and the 1-5% of polyether glycol and small molecule chain extender three total mass.
Among the present invention, the polyisocyanates in the described step 1) comprises diphenylmethanediisocyanate, tolylene diisocyanate.The pure and mild polyether glycol of polyester polyols in the step 1) comprises: polycaprolactone glycol, poly-hexanodioic acid-1,4-butanediol ester glycol, polypropylene glycol.
The object of the present invention is to provide the preparation method of a kind of tensile strength height, chitin whisker modified aqueous polyurethane that elongation at break is high.
To achieve these goals, the technical solution adopted in the present invention is as follows:
1) by any one of polyisocyanates and following three kinds of raw materials: raw material polyester polyol or raw material polyether glycol or raw material polyether glycol and polyester polyols alcohol mixture, mixed stirring reaction 2-3 hour down at 70-90 ℃, obtain polyurethane prepolymer;
Wherein, when polyisocyanates mixes with the mixture of polyester polyol or polyether glycol or polyether glycol and polyester polyol, the mass percent of the mixture of polyisocyanates and polyester polyol or polyether glycol or polyether glycol and polyester polyol is respectively: polyisocyanates is 65-90%, and the mixture of polyester polyol or polyether glycol or polyether glycol and polyester polyol is 10-35%.
Wherein, when polyisocyanates mixed with the mixture material of the pure and mild polyether glycol of polyester polyols, the pure and mild polyether glycol of polyester polyols wherein mass percent between the two was any proportioning;
2) under 70-90 ℃, added the small molecule chain extender stirring reaction 1-2 hour in the polyurethane prepolymer that in step 1), obtains, and use the acetone viscosity reduction; Wherein, the add-on of small molecule chain extender is the 10-50% of polyisocyanates quality; The add-on of acetone is: polyisocyanates, polyester polyol are or/and the 10-30% of polyether glycol, three kinds of raw materials quality sums of small molecule chain extender;
3) with step 2) reaction product that obtains is cooled to below 40 ℃, adds neutralization reagent then, the adjusting pH value is 6-8, in and after 5-10 minute, water-dispersion on the rocks again, aqueous polyurethane emulsion; Add the chitin whisker blend in the aqueous polyurethane emulsion, the add-on of chitin whisker is: polyisocyanates, polyester polyol are or/and the 1-5% of polyether glycol and three kinds of raw materials quality sums of small molecule chain extender; Vacuumize then and remove acetone, the mass percent of control solid content is 5-40%, promptly makes the chitin whisker modified aqueous polyurethane.
Described small molecule chain extender is any one or any one the above mixing in dibasic alcohol, diamine, trivalent alcohol, the tertiary amine, is any proportioning during any one above mixing.
Described chitin whisker gets the described sulphuric acid hydrolysis that is hydrolyzed to by the chitin hydrolysis.
The preparation method of described chitin whisker is: chitin is stirred in ebullient 5 wt%KOH solution removed deproteinize in 6 hours.The suspension that obtains at room temperature stirs a night, filters, with distilled water wash for several times.NaCl with the 17g/L of the sodium acetate buffer that contains 0.3M
2The aqueous solution was bleached 6 hours down at 80 ℃.Suspension keeps removing in 48 hours residual protein in 5 wt%KOH solution.In 3600 rev/mins whizzer centrifugal 15 minutes afterwards, the acidolysis under boiling state of the corresponding lg chitin of 3N/30mlHCI was stirred 90 minutes.With the muddy liquid distilled water diluting of gained, 3600 rev/mins of recentrifuge 15 minutes (3 times).The 2 hours dialysed overnight in distilled water again of afterwards muddy liquid being dialysed in flowing water reach 4 up to pH value.Obtain dispersion liquid with supersound process then.At last, add the sodiumazide bacteria growing inhibiting, dispersion liquid is placed in 6 ℃ of environment.Described chitin is mainly derived from shrimp shell, crab shell etc., and content is up to 58%-85%.
The present invention is by adding chitin whisker in the building-up process of aqueous polyurethane emulsion, and the mechanical property that its emulsion is solidified the mould material that the back forms significantly improves, and it can keep improving tensile strength simultaneously than high elongation at tear.Chitin whisker among the present invention is to be got by the chitin hydrolysis, and chitin is mainly derived from shrimp shell and crab shell, and is with low cost, the source is abundant, and the processing condition of preparation, chitin extraction whisker are simple.Aqueous polyurethane is a kind of ep-type material, that the present invention will originate will be abundant, the simple chitin whisker of technology combines the using value that the material that has not only obtained improved performance has also improved chitin with environment-friendly water-based polyurethane, expanded its use range, its low production cost and have environmental protection, biodegradable characteristics simultaneously, and technology of the present invention is simple, therefore has higher scientific and technological content.The mechanical property of the resulting chitin whisker modified aqueous polyurethane of this method is significantly improved, and can be used as materials such as film, coating, sizing agent.
Embodiment
In order to understand the present invention better, further illustrate content of the present invention below in conjunction with embodiment, but content of the present invention not only is confined to the following examples.Under the spirit and scope that do not deviate from inventive concept, variation and advantage that those skilled in the art can expect all are included among the present invention, and are protection domain with the appending claims.
Embodiment 1:
A kind of preparation method of chitin whisker modified aqueous polyurethane, it comprises the steps:
1) with polyester diol (polycaprolactone glycol, the PCL of calculated amount
2000, Mn is 2000) and be blended in 70 ℃ of following stirring reactions 2 hours with diphenylmethanediisocyanate (MDI), get polyurethane prepolymer; The mass percent of polyester diol and diphenylmethanediisocyanate is: polyester diol 30%, diphenylmethanediisocyanate 70%;
Among the present invention, polyisocyanates can be diphenylmethanediisocyanate or tolylene diisocyanate; The pure and mild polyether glycol of polyester polyols can be polycaprolactone glycol, poly-hexanodioic acid-1,4-butanediol ester glycol or polypropylene glycol.
2) under 85 ℃, in polyurethane prepolymer, add small molecule chain extender: 2,2 '-dimethylol propionic acid (DMPA), the add-on of small molecule chain extender DMPA is 20% of a diphenylmethanediisocyanate quality, stirring reaction 1 hour, and use the acetone viscosity reduction, the add-on of acetone be polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 10%;
3) after reaction was finished, temperature dropped to (as 0-39 ℃) below 40 ℃, and addings waits in the triethylamine (TEA) of DMPA molar weight and salify 5 minutes again, the add-on of triethylamine identical with the amount of DMPA (the adjusting pH value is within the 6-8 scope); Under high-speed stirring (2000-4000 rev/min), chitin whisker frozen water solution added disperses, the chitin whisker add-on be polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 1%.The chitin whisker add-on can be in the scope of 0.1-30%.Vacuumize then and remove acetone and obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion); The solid content of chitin whisker composite aqueous polyurethane emulsion is controlled by the water yield that adds at 20%();
4) under 60 ℃, with chitin whisker composite aqueous polyurethane emulsion casting film-forming on polyfluortetraethylene plate.
After mould material is cut into sheet, be 35%, place after 7 days under the room temperature and carry out performance test at constant humidity.The mechanical property of the sheet material of preparation sees Table 1.Mechanical property is with reference to State Standard of the People's Republic of China GB4456-84, newly thinks carefully in Shenzhen on the CMT6503 instrument of testing tool company to record, and rate of extension is 200 mm/min.
Embodiment 2:
A kind of preparation method of chitin whisker modified aqueous polyurethane, it comprises the steps:
1) polyester diol (polycaprolactone glycol, Mn are 2000) of calculated amount and the mixture and the diphenylmethanediisocyanate (MDI) of polyether Glycols (polypropylene glycol) are blended in 70 ℃ of following stirring reactions 2 hours, get polyurethane prepolymer; The mass percent of polyester diol and diphenylmethanediisocyanate is: the mixture 35% of the pure and mild polyether Glycols of polyester binary, diphenylmethanediisocyanate 65%;
2) under 85 ℃, in polyurethane prepolymer, add small molecule chain extender: 2,2 '-dimethylol propionic acid (DMPA), the add-on of small molecule chain extender DMPA is 20% of a diphenylmethanediisocyanate quality, stirring reaction 1 hour, and use the acetone viscosity reduction, the add-on of acetone be the pure and mild polyether Glycols of polyester binary mixture, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 20%;
3) after reaction was finished, temperature dropped to (as 0-39 ℃) below 40 ℃, and addings waits in the triethylamine (TEA) of DMPA molar weight and salify 5 minutes again, the add-on of triethylamine identical with the amount of DMPA (the adjusting pH value is within the 6-8 scope); Under high-speed stirring (2000-4000 rev/min), the adding of chitin whisker frozen water solution is disperseed, the chitin whisker add-on be the pure and mild polyether Glycols of polyester binary mixture, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 1%; Vacuumize then and remove acetone and obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion); The solid content of chitin whisker composite aqueous polyurethane emulsion is controlled by the water yield that adds at 30%();
4) under 60 ℃, with chitin whisker composite aqueous polyurethane emulsion casting film-forming on polyfluortetraethylene plate.
After mould material is cut into sheet, be 35%, place after 7 days under the room temperature and carry out performance test at constant humidity.The mechanical property of the sheet material of preparation sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 3:
Substantially the same manner as Example 1, difference is: the chitin whisker of interpolation is polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 2%, obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion).The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 4:
Substantially the same manner as Example 2, difference is: the chitin whisker of interpolation is mixture, the diphenylmethanediisocyanate and 2 of the pure and mild polyether Glycols of polyester binary, 2 '-the dimethylol propionic acid total mass 2%, obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion).The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 5:
A kind of preparation method of chitin whisker modified aqueous polyurethane, it comprises the steps:
1) polyester diol (polycaprolactone glycol, Mn are 2000) of calculated amount and the mixture and the diphenylmethanediisocyanate (MDI) of polyether Glycols (polypropylene glycol) are blended in 70 ℃ of following stirring reactions 2 hours, get polyurethane prepolymer; The mass percent of polyester diol and diphenylmethanediisocyanate is: the pure and mild polyether Glycols mixture 25% of polyester binary, diphenylmethanediisocyanate 75%;
2) under 85 ℃, in polyurethane prepolymer, add small molecule chain extender: 2,2 '-dimethylol propionic acid (DMPA), the add-on of small molecule chain extender DMPA is 20% of a diphenylmethanediisocyanate quality, stirring reaction 1 hour, and use the acetone viscosity reduction, the add-on of acetone be the pure and mild polyether Glycols of polyester binary mixture, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 30%;
3) after reaction was finished, temperature dropped to (as 0-39 ℃) below 40 ℃, and addings waits in the triethylamine (TEA) of DMPA molar weight and salify 5 minutes again, the add-on of triethylamine identical with the amount of DMPA (the adjusting pH value is within the 6-8 scope); Under high-speed stirring (2000-4000 rev/min), the adding of chitin whisker frozen water solution is disperseed, the chitin whisker add-on be the pure and mild polyether Glycols of polyester binary mixture, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 1%; Vacuumize then and remove acetone and obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion); The solid content of chitin whisker composite aqueous polyurethane emulsion is controlled by the water yield that adds at 15%();
4) under 60 ℃, with chitin whisker composite aqueous polyurethane emulsion casting film-forming on polyfluortetraethylene plate.
After mould material is cut into sheet, be 35%, place after 7 days under the room temperature and carry out performance test at constant humidity.The mechanical property of the sheet material of preparation sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 6:
Substantially the same manner as Example 1, difference is: the chitin whisker of interpolation is polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 3%, obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion).The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 7:
Substantially the same manner as Example 5, difference is: the chitin whisker of interpolation is mixture, the diphenylmethanediisocyanate and 2 of the pure and mild polyether Glycols of polyester binary, 2 '-the dimethylol propionic acid total mass 3%, obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion).The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 8:
A kind of preparation method of chitin whisker modified aqueous polyurethane, it comprises the steps:
1) polyester diol (polycaprolactone glycol, Mn are 2000) with calculated amount is blended in 70 ℃ of following stirring reactions 2 hours with diphenylmethanediisocyanate (MDI), gets polyurethane prepolymer; The mass percent of polyester diol and diphenylmethanediisocyanate is: polyester diol 20%, diphenylmethanediisocyanate 80%;
2) under 85 ℃, in polyurethane prepolymer, add small molecule chain extender: 2,2 '-dimethylol propionic acid (DMPA), the add-on of small molecule chain extender DMPA is 20% of a diphenylmethanediisocyanate quality, stirring reaction 1 hour, and use the acetone viscosity reduction, the add-on of acetone be polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 20%;
3) after reaction was finished, temperature dropped to (as 0-39 ℃) below 40 ℃, and addings waits in the triethylamine (TEA) of DMPA molar weight and salify 5 minutes again, the add-on of triethylamine identical with the amount of DMPA (the adjusting pH value is within the 6-8 scope); Under high-speed stirring (2000-4000 rev/min), chitin whisker frozen water solution added disperses, the chitin whisker add-on be polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 2%; Vacuumize then and remove acetone and obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion); The solid content of chitin whisker composite aqueous polyurethane emulsion is controlled by the water yield that adds at 10%();
4) under 60 ℃, with chitin whisker composite aqueous polyurethane emulsion casting film-forming on polyfluortetraethylene plate.
After mould material is cut into sheet, be 35%, place after 7 days under the room temperature and carry out performance test at constant humidity.The mechanical property of the sheet material of preparation sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 9:
Substantially the same manner as Example 1, difference is: the chitin whisker of interpolation is polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 4%, obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion).The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 10:
Substantially the same manner as Example 8, difference is: the chitin whisker of interpolation is polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 4%, obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion).The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 11:
A kind of preparation method of chitin whisker modified aqueous polyurethane, it comprises the steps:
1) polyester diol (PBA2000, Mn are 2000 for poly-hexanodioic acid-1,4-butanediol ester glycol) with calculated amount is blended in 70 ℃ of following stirring reactions 2 hours with tolylene diisocyanate (TDI), gets polyurethane prepolymer; The mass percent of polyester diol and diphenylmethanediisocyanate is: polyester diol 15%, diphenylmethanediisocyanate 85%;
2) under 85 ℃, in polyurethane prepolymer, add small molecule chain extender: 2,2 '-dimethylol propionic acid (DMPA), the add-on of small molecule chain extender DMPA is 20% of a tolylene diisocyanate quality, stirring reaction 1 hour, and use the acetone viscosity reduction, the add-on of acetone be polyester diol, tolylene diisocyanate and 2,2 '-the dimethylol propionic acid total mass 10%;
3) after reaction was finished, temperature dropped to (as 0-39 ℃) below 40 ℃, and addings waits in the triethylamine (TEA) of DMPA molar weight and salify 5 minutes again, the add-on of triethylamine identical with the amount of DMPA (the adjusting pH value is within the 6-8 scope); Under high-speed stirring (2000-4000 rev/min), chitin whisker frozen water solution added disperses, the chitin whisker add-on be polyester diol, tolylene diisocyanate and 2,2 '-the dimethylol propionic acid total mass 5%; Vacuumize then and remove acetone and obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion); The solid content of chitin whisker composite aqueous polyurethane emulsion is controlled by the water yield that adds at 30%();
4) under 60 ℃, with chitin whisker composite aqueous polyurethane emulsion casting film-forming on polyfluortetraethylene plate.
After mould material is cut into sheet, be 35%, place after 7 days under the room temperature and carry out performance test at constant humidity.The mechanical property of the sheet material of preparation sees Table 1.Mechanics Performance Testing is with embodiment 1.
Embodiment 12:
Substantially the same manner as Example 1, difference is: the chitin whisker of interpolation is polyester diol, diphenylmethanediisocyanate and 2,2 '-the dimethylol propionic acid total mass 5%, obtain chitin whisker modified aqueous polyurethane (or claim chitin whisker composite aqueous polyurethane emulsion).The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
Implement 13:
Substantially the same manner as Example 1, difference is: do not add chitin whisker, obtain aqueous polyurethane emulsion.The mechanical property of preparation sheet material sees Table 1.Mechanics Performance Testing is with embodiment 1.
More than show:
With embodiment 13 relatively, other have used the mechanical property (tensile strength, Young's modulus) of the product chitin whisker composite aqueous polyurethane that preparation method's of the present invention embodiment makes to be significantly improved, but also have kept higher elongation at break.
2. can be found relatively by the experimental result of embodiment 13,1,3,6 that along with the increase of chitin whisker content, the tensile strength of its product increases gradually, elongation at break decreases;
3. relatively can find by the experimental result of embodiment 3,6,9,12, continuation increase along with chitin whisker content, the product that the tensile strength contrast traditional method of its product makes still has remarkable increase, but it is no longer in rising trend that it increases effect, and its product elongation at break will further reduce;
4. can find relatively by the experimental result of embodiment 13,1,3,6,9,12 that along with the increase of chitin whisker content, the Young's modulus of its product increases always.
The interpolation chitin whisker that the present invention proposes innovation carries out the preparation method of modified aqueous polyurethane, wherein, the addition of chitin whisker can be controlled in polyisocyanates, polyester polyol or/and the 1-5% of polyether glycol, three kinds of raw materials quality sums of small molecule chain extender.
Above experimental result as seen, not adding the method that chitin whisker prepares aqueous polyurethane with tradition compares, adopt the inventive method to prepare the chitin whisker modified aqueous polyurethane, when the addition of chitin whisker during at 1-5%, mechanical properties such as the tensile strength of the modified aqueous polyurethane that the inventive method makes, Young's modulus all are optimized, and have kept higher elongation at break.As seen, preparation method of the present invention has actual application value preferably.