阅读说明：本技术 聚氨酯组合物和聚氨酯材料的制备方法及应用 (Polyurethane composition, preparation method and application of polyurethane material ) 是由 肖勇明 李庶 刘拼拼 朱姝玥 聂一彪 于 2021-07-15 设计创作，主要内容包括：本发明涉及混凝土活塞技术领域,公开了一种聚氨酯组合物和聚氨酯材料的制备方法及应用。所述聚氨酯组合物包括聚醚类聚氨酯预聚体、扩链剂和萘酰亚胺类聚氨酯预聚体；其中,所述聚醚类聚氨酯预聚体和萘酰亚胺类聚氨酯预聚体的重量比为100：0.1-10。所述聚氨酯材料的制备方法包括将上述所述聚氨酯组合物进行成型和硫化。本发明将聚醚类聚氨酯预聚体和萘酰亚胺类聚氨酯预聚体按照特定的比例配合使用,萘酰亚胺基团的引入,提高了聚氨酯活塞的耐高温性能、耐酸碱性能、力学强度、耐水解性能、压缩永久变形及耐磨性能。聚氨酯活塞寿命显著提高。(The invention relates to the technical field of concrete pistons, and discloses a polyurethane composition, a preparation method and application of a polyurethane material. The polyurethane composition comprises a polyether polyurethane prepolymer, a chain extender and a naphthalimide polyurethane prepolymer; wherein the weight ratio of the polyether polyurethane prepolymer to the naphthalimide polyurethane prepolymer is 100: 0.1-10. The preparation method of the polyurethane material comprises the steps of forming and vulcanizing the polyurethane composition. According to the invention, the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer are used in a matched manner according to a specific proportion, and the introduction of naphthalimide groups improves the high temperature resistance, acid and alkali resistance, mechanical strength, hydrolysis resistance, compression set and wear resistance of the polyurethane piston. The service life of the polyurethane piston is obviously prolonged.)

1. A polyurethane composition is characterized by comprising a polyether polyurethane prepolymer, a chain extender and a naphthalimide polyurethane prepolymer;

wherein the weight ratio of the polyether polyurethane prepolymer to the naphthalimide polyurethane prepolymer is 100: 0.1-10.

2. The polyurethane composition according to claim 1, wherein the polyether polyurethane prepolymer has a-NCO content of 5 to 10 wt%;

and/or, the content of-NCO in the naphthalimide polyurethane prepolymer is 3-8 wt%;

and/or the chain extender is dihydric alcohol of C2-C10;

and/or the weight ratio of the total weight of the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer to the chain extender is 100: 8-10.

3. The polyurethane composition of claim 2, wherein the chain extender is at least one of 1, 4-butanediol, ethylene glycol, diethylene glycol, and 1, 6-hexanediol.

4. The polyurethane composition of claim 1, wherein the naphthalimide-based polyurethane prepolymer is prepared by a method comprising:

(1) in the presence of a solvent, reacting amino naphthol and dianhydride to obtain naphthol imide;

(2) reacting naphthol imide with isocyanate compounds in the presence of a catalyst to obtain the naphthalimide polyurethane prepolymer.

5. The polyurethane composition of claim 4, wherein the dianhydride is a phenyl dianhydride, preferably at least one of pyromellitic dianhydride, 4, 4-oxydiphthalic dianhydride, and 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride;

and/or the solvent is at least one of N, N-dimethylformamide, N-methylpyrrolidone and dimethylacetamide;

and/or, the molar ratio of the amino naphthol to the dianhydride is 1.5-3: 1;

and/or, in the step (1), the reaction conditions comprise: firstly reacting for 0.5-2h at 0-10 ℃, and then heating to 50-80 ℃ for reacting for 2-4 h.

6. The polyurethane composition according to claim 4, wherein in the step (2), the isocyanate-based compound is a diisocyanate-based compound, preferably at least one of 4,4 '-diphenylmethane diisocyanate, 2, 4' -toluene diisocyanate, and 3,5 '-dimethyl-4, 4' -diphenyl diisocyanate;

and/or the catalyst is an organic tin compound, preferably dibutyltin dilaurate and/or stannous octoate;

and/or the weight ratio of the catalyst to the naphthol imide to the isocyanate compound is 0.5-3: 50-70: 30-50 parts of;

and/or, in the step (2), the reaction conditions comprise: reacting for 0.5-4h at 50-90 ℃.

7. A process for the preparation of a polyurethane material, characterized in that it comprises shaping and vulcanizing a polyurethane composition according to any one of claims 1 to 6.

8. The method according to claim 7, wherein the method further comprises subjecting the mixture of the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer and the chain extender to vacuum treatment independently of each other.

9. The production method according to claim 8, wherein the vulcanization includes a first vulcanization, a second vulcanization, and a third vulcanization;

the conditions of the first vulcanization comprise: sulfurizing at 110-120 deg.c for 50-70 min;

the conditions of the second vulcanization comprise: vulcanizing at 90-120 deg.C for 16-20 h;

the conditions of the third vulcanization comprise: vulcanization is continued for 1-3 weeks at normal temperature and in the dark.

10. A polyurethane material, characterized in that it is prepared by the process according to any one of claims 7 to 9.

11. Use of the polyurethane composition according to any one of claims 1 to 6 and the polyurethane material according to claim 10 in pistons of concrete pump vehicles.

Technical Field

The invention relates to the technical field of concrete pistons, in particular to a polyurethane composition, a preparation method and application of a polyurethane material.

Background

The concrete piston is a key wearing part of concrete pumping equipment and is also a high-frequency wearing part. The working environment of the concrete piston is very severe, one needs to bear higher pressure, the other needs to have good sealing performance with the concrete cylinder, the third needs to convey high-sand-content and high-corrosion liquid, and the fourth needs to bear high-temperature environment. The piston fault will influence the continuous construction of pump truck, and the piston leaks the thick liquid risk that will bring the pollution hydraulic oil, and the work progress is changed the piston and will be brought risks such as stifled pipe. The polyurethane system composed of polytetrahydrofuran ether glycol (PTMG) and 4,4 '-diphenylmethane diisocyanate (MDI) has the advantages of excellent low-temperature flexibility, weather resistance, hydrolysis resistance, good rebound resilience of MDI, flex fatigue resistance, small hysteresis loss, low toxicity and the like of polyether polyol, but the heat resistance and the tensile strength of the polyurethane piston composed of polytetrahydrofuran ether glycol (PTMG) and 4, 4' -diphenylmethane diisocyanate (MDI) are slightly low.

CN109053981A discloses a concrete piston material, a concrete piston for a high-abrasion-resistance concrete pump and a preparation method thereof, wherein the concrete piston material comprises 100 parts by weight of polyether polyurethane prepolymer; 15-20 parts of chain extender and 2-10 parts of silane coupling agent modified carbide; the chain extender is selected from di-o-chloro diphenylamine methane and/or dimethyl-thio toluene diamine; the carbide is selected from boron carbide or silicon carbide. However, the reaction rate of the polyether polyurethane prepolymer and the diamine chain extender is high, and meanwhile, the compatibility of the carbide and the polyurethane prepolymer is poor, and the material reinforcing effect is poor.

CN111057206A discloses a wear-resistant polyurethane elastomer composition and a split piston, the composition includes: 100 parts of polycaprolactone, 25-35 parts of diphenylmethane diisocyanate, 10-15 parts of 1, 4-butanediol, 1-5 parts of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane, 0.3-0.5 part of organic bismuth catalyst, 0.3-0.5 part of antioxidant and 0.4-0.6 part of ultraviolet absorbent. However, the polyester system polyurethane has poor low temperature resistance and poor applicability.

Disclosure of Invention

The invention aims to prolong the service life of a polyurethane piston and provides a preparation method and application of a naphthalimide polyurethane prepolymer.

In order to achieve the above object, the present invention provides in a first aspect a polyurethane composition comprising a polyether polyurethane prepolymer, a chain extender, and a naphthalimide polyurethane prepolymer;

wherein the weight ratio of the polyether polyurethane prepolymer to the naphthalimide polyurethane prepolymer is 100: 0.1-10.

The second aspect of the present invention provides a method for preparing a polyurethane material, which comprises molding and vulcanizing the polyurethane composition.

The third aspect of the invention provides a polyurethane material, which is prepared by the preparation method.

The fourth aspect of the invention provides an application of the polyurethane composition and the polyurethane material in a concrete pump truck piston.

Through the technical scheme, the invention has the following beneficial effects:

according to the invention, the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer are used in a matched manner according to a specific proportion, and the introduction of naphthalimide groups improves the high temperature resistance, acid and alkali resistance, mechanical strength, hydrolysis resistance, compression set and wear resistance of the polyurethane piston. The piston life (average usage amount) of polyurethane is obviously improved.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a polyurethane composition in a first aspect, which comprises a polyether polyurethane prepolymer, a chain extender and a naphthalimide polyurethane prepolymer;

wherein the weight ratio of the polyether polyurethane prepolymer to the naphthalimide polyurethane prepolymer is 100: 0.1 to 10, preferably 100: 2-6.

According to the present invention, the kind of the polyether polyurethane prepolymer is not particularly limited, and it is preferable that the polyether polyurethane prepolymer has a-NCO content of 5 to 10% by weight in order to improve hydrolysis resistance and low temperature resistance of a polyurethane piston.

According to the present invention, it is preferable that the content of-NCO in the naphthalimide-based polyurethane prepolymer is 3 to 8% by weight.

According to a particularly preferred embodiment of the present invention, the polyether polyurethane prepolymer is prepared from polyether diol and isocyanate compound according to the ratio of 55-65: 35-45 weight percent.

According to the present invention, the kind of the isocyanate compound is not particularly limited, and preferably, the isocyanate compound is a diisocyanate compound, and is preferably at least one of 4,4 '-diphenylmethane diisocyanate, 2, 4' -toluene diisocyanate, and 3,5 '-dimethyl-4, 4' -diphenyl diisocyanate (TODI).

According to the present invention, the kind of the polyether glycol is not particularly limited, and preferably, the polyether glycol is at least one of polytetrahydrofuran ether glycol, polypropylene oxide glycol and polyethylene oxide glycol.

According to the present invention, preferably, the weight ratio of the total weight of the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer to the chain extender is 100: 8-10. When the amount of the chain extender is within the range, the prepared polyurethane piston has good mechanical property and abrasion performance, and when the amount of the chain extender is higher or lower than the range, the mechanical property and the abrasion performance of the prepared polyurethane piston are reduced.

According to the present invention, the kind of the chain extender is not particularly limited, and may be a chain extender commonly used in the art. Preferably, the chain extender is a dihydric alcohol of C2-C10; further preferably, the chain extender is at least one of 1, 4-butanediol, ethylene glycol, diethylene glycol and 1, 6-hexanediol. By using the alcohol chain extender, the invention can better control the reaction rate and obtain the polyurethane material with good hydrolysis resistance and toughness.

According to the present invention, the mode of obtaining the naphthalimide-based polyurethane prepolymer is not particularly limited, and the method for preparing the naphthalimide-based polyurethane prepolymer preferably includes:

(1) in the presence of a solvent, reacting amino naphthol and dianhydride to obtain naphthol imide;

(2) reacting naphthol imide with isocyanate compounds in the presence of a catalyst to obtain the naphthalimide polyurethane prepolymer.

According to the present invention, the type of the dianhydride is not particularly limited, and the dianhydride is preferably phenyl dianhydride, and more preferably at least one of pyromellitic dianhydride, 4, 4-oxydiphthalic dianhydride, and 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride.

According to the present invention, the kind of the solvent is not particularly limited, and preferably, the solvent is at least one of N, N-dimethylformamide, N-methylpyrrolidone, and dimethylacetamide.

According to the invention, preferably, the aminonaphthol is 1-amino-5-naphthol.

According to the invention, preferably, the molar ratio of aminonaphthol to dianhydride is 1.5-3: 1.

according to the present invention, preferably, in step (1), the reaction conditions include: the reaction is carried out for 0.5 to 2 hours at 0 to 10 ℃ (ice water bath), and then the temperature is increased to 50 to 80 ℃ for 2 to 4 hours.

According to the present invention, preferably, in the step (2), the isocyanate-based compound is a diisocyanate-based compound, preferably at least one of 4,4 '-diphenylmethane diisocyanate, 2, 4' -tolylene diisocyanate, and 3,5 '-dimethyl-4, 4' -diphenyldiisocyanate.

According to the present invention, the kind of the catalyst is not particularly limited, and the catalyst is preferably an organotin compound, and more preferably dibutyltin dilaurate and/or stannous octoate.

According to the present invention, preferably, the weight ratio of the catalyst, the naphthol imide and the isocyanate compound is 0.5 to 3: 50-70: 30-50.

According to the present invention, preferably, in the step (2), the reaction conditions include a reaction at 50 to 90 ℃ for 0.5 to 4 hours.

According to the present invention, in step (2), preferably, after the reaction is completed, vacuum degassing is further performed for 0.5 to 4 hours, and the reaction product is cooled to obtain a naphthalimide polyurethane prepolymer.

The second aspect of the present invention provides a method for preparing a polyurethane material, which comprises molding and vulcanizing the polyurethane composition.

According to the present invention, preferably, the preparation method further comprises subjecting the mixture of the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer and the chain extender to vacuum treatment independently of each other.

According to the present invention, preferably, the vulcanization includes a first vulcanization, a second vulcanization and a third vulcanization; the conditions of the first vulcanization comprise: sulfurizing at 110-120 deg.c for 50-70 min; the conditions of the second vulcanization comprise: vulcanizing at 90-120 deg.C for 16-20 h; the conditions of the third vulcanization comprise: vulcanization is continued for 1-3 weeks at normal temperature and in the dark.

The normal temperature in the invention means 15-40 ℃.

The third aspect of the invention provides a polyurethane material, which is prepared by the preparation method.

The fourth aspect of the invention provides an application of the polyurethane composition and the polyurethane material in a concrete pump truck piston.

The present invention will be described in detail below by way of examples. In the following examples of the present invention,

the content of-NCO in the prepolymer is determined by the following steps of GB/T12009.4-2016 part 4 of aromatic isocyanate for polyurethane production: and measuring the content of the isocyanic acid radical.

Preparation example 1

Preparation of naphthalimide polyurethane prepolymer

1-amino-5-naphthol and 4, 4-oxydiphthalic dianhydride in the presence of a solvent (N, N-dimethylformamide) are reacted according to a ratio of 2: 1, reacting for 1.5h at 0 ℃ (ice water bath), then heating to 80 ℃ for 3h, and removing the reaction solvent to obtain naphthol imide; the catalyst (dibutyltin dilaurate), naphthol imide and 4, 4' -diphenylmethane diisocyanate were then mixed in the following ratio 1.5: 55: 45 by weight percent, reacting for 2 hours at 80 ℃, vacuumizing and defoaming for 2 hours, and cooling to obtain the naphthalimide polyurethane prepolymer.

The content of-NCO in the obtained naphthalimide polyurethane prepolymer was 5% by weight.

Preparation example 2

A naphthalimide-based polyurethane prepolymer was prepared according to the method of preparation example 1, except that 4, 4-oxydiphthalic dianhydride was replaced with pyromellitic dianhydride, and the weight ratio of the catalyst, the naphthoylimide and the 4, 4' -diphenylmethane diisocyanate was 1.5: 70: 30.

the content of-NCO in the obtained naphthalimide polyurethane prepolymer was 5% by weight.

Example 1

(1) Preparation of polyether polyurethane prepolymer

Adding polytetrahydrofuran ether glycol (the number average molecular weight is 1000g/mol) into a synthesis kettle, vacuumizing and dehydrating for 1.5h at 120 ℃, cooling to 80 ℃, and adding 4, 4' -diphenylmethane diisocyanate (MDI), wherein the weight ratio of the polytetrahydrofuran ether glycol to the MDI is 60: 40, reacting for 2 hours at 80 ℃, then removing bubbles, cooling and sealing to obtain the polyether polyurethane prepolymer.

The content of-NCO in the polyether polyurethane prepolymer obtained was 9.3% by weight.

(2) Preparation of polyurethane piston

Preheating: preheating a chamber A and a chamber B of a casting machine, wherein the temperature in a kettle of the chamber A is 70 ℃, the temperature in a kettle of the chamber B is 30 ℃, then placing the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer of preparation example 1 into the chamber A, and placing a chain extender (1, 4-butanediol) into the chamber B, wherein the weight ratio of the polyether polyurethane prepolymer to the naphthalimide polyurethane prepolymer is 100: 2.

removing bubbles: stirring and vacuum pumping are then started for the A chamber and the B chamber respectively until the liquid in the A chamber and the B chamber is basically bubble-free.

Pouring and vulcanizing: preheating a mould to the temperature required by first vulcanization, and after metering, mixing a mixture of the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer in the chamber A and a chain extender in the chamber B according to the weight ratio of 100: 9.4, pouring the mixture into a mold for primary vulcanization, keeping the mold at 115 ℃ for vulcanization for 60min, and taking out the mold. Then, the second vulcanization is carried out, and the mixture is placed in an oven at 100 ℃ for vulcanization for 16 h. And then placing the piston in a dark room for continuous vulcanization for two weeks, and trimming to obtain the polyurethane piston.

Example 2

Preparation of a polyurethane piston was carried out in the same manner as in example 1 except that the naphthalimide-based polyurethane prepolymer of preparation example 1 was replaced with the naphthalimide-based polyurethane prepolymer of preparation example 2.

Examples 3 to 7

A polyurethane piston was prepared in the same manner as in example 2 except that the weight ratios of the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer were (100: 0.1), (100: 4), (100: 6), (100: 8) and (100: 10), respectively.

Examples 8 to 12

The polyurethane piston was prepared by following the procedure of example 2 except that the weight ratio of polytetrahydrofuran ether glycol to 4, 4' -diphenylmethane diisocyanate was changed so that the contents of-NCO in the polyether polyurethane prepolymer were 5.6 wt%, 6.8 wt%, 7.6 wt%, 8.5 wt%, and 9.6 wt%, respectively.

Examples 13 to 14

A polyurethane piston was prepared in the same manner as in example 2 except that the weight ratios of the mixture of the polyether polyurethane prepolymer and the naphthalimide polyurethane prepolymer in the A compartment and the chain extender in the B compartment were (100: 8.5) and (100: 9.8), respectively.

Comparative example 1

The preparation of a polyurethane piston was carried out as in example 2, except that no naphthalimide-based polyurethane prepolymer was added.

Comparative example 2

The preparation of a polyurethane piston was carried out as in example 2, except that the weight ratio of polyether polyurethane prepolymer to naphthalimide polyurethane prepolymer was 100: 15.

comparative example 3

The preparation of the polyurethane piston was carried out as in example 2, except that the polyether polyurethane prepolymer was replaced with a polycaprolactone polyurethane prepolymer.

Test example 1

The above comparative examples and the prepared polyurethane pistons were subjected to performance tests, and the test results are shown in table 1.

Hardness of

Vulcanized rubber or thermoplastic rubber was tested according to GB/T531.1-2008 method part 1 of the indentation hardness test: the standard of the Shore durometer method is used for testing.

Tensile strength

The test is carried out according to the standard of GB/T528-2009 vulcanized rubber or thermoplastic rubber tensile stress strain performance measurement.

Elongation at Break

The test is carried out according to the standard of GB/T528-2009 vulcanized rubber or thermoplastic rubber tensile stress strain performance measurement.

Tear strength

The tests were carried out according to the standard for determination of the tear strength of GB/T529- & 2008 cured rubber or thermoplastic rubber (pant-, right-angle and crescent-shaped test specimens).

Rebound resilience

The test is carried out according to the determination standard of the rebound resilience of GB/T1681-2009 vulcanized rubber.

DIN abrasion

The test is carried out according to the GB/T9867 plus 2008 determination standard of the wear resistance of vulcanized rubber or thermoplastic rubber (rotating roller type wearing machine method).

Life span

The testing method comprises the steps of carrying out loading examination on the piston products under the same vehicle type and the same working condition, and counting the average usage amount.

TABLE 1

The results in table 1 show that the polyurethane piston product prepared from the polyurethane composition of the naphthalimide polyurethane prepolymer, the polyether polyurethane prepolymer and the alcohol chain extender has good mechanical property and wear resistance, and the service life is obviously prolonged.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.