阅读说明：本技术 一种耐热氧老化聚氨酯弹性体材料的制备方法与应用 (Preparation method and application of thermal-oxidative-aging-resistant polyurethane elastomer material ) 是由 谈静 李禹辰 任旭东 陈刚 房权生 于 2020-12-18 设计创作，主要内容包括：本发明公开一种耐热氧老化聚氨酯弹性体材料的制备方法与应用。制备：(1)将异氰酸酯与端羟基液体丁腈加入有机溶剂中进行混合预聚,得到聚氨酯预聚物；且混合预聚过程在氮气氛围、加热和搅拌的条件下进行；(2)将碳纳米点分散于上述聚氨酯预聚物中并加热,搅拌,得混合物；(3)在混合物中加入扩链剂,然后硫化,得到耐热氧老化聚氨酯弹性体。应用：将制备方法制得的耐热氧老化聚氨酯弹性体材料作为工业机器装备用综合电缆的保护套材料。本发明制备的耐热氧老化聚氨酯弹性体材料,首次将碳纳米点作为新型防老剂原位复合到聚氨酯弹性体材料中,显著提高了端羟基液体丁腈型聚氨酯弹性体的耐热氧老化性能,且本发明的制备方法简单,成本低。(The invention discloses a preparation method and application of a thermal-oxidative-aging-resistant polyurethane elastomer material. Preparation: (1) adding isocyanate and hydroxyl-terminated butyronitrile into an organic solvent for mixing and prepolymerization to obtain a polyurethane prepolymer; the mixing and prepolymerization process is carried out under the conditions of nitrogen atmosphere, heating and stirring; (2) dispersing carbon nanodots in the polyurethane prepolymer, heating and stirring to obtain a mixture; (3) and adding a chain extender into the mixture, and then vulcanizing to obtain the thermal-oxidative-aging-resistant polyurethane elastomer. The application comprises the following steps: the thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the preparation method is used as a protective sleeve material of a comprehensive cable for industrial machine equipment. According to the thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the invention, the carbon nanodots serving as the novel anti-aging agents are compounded into the polyurethane elastomer material in situ for the first time, so that the thermal-oxidative-aging-resistant performance of the hydroxyl-terminated liquid butyronitrile type polyurethane elastomer is obviously improved, and the preparation method is simple and low in cost.)

1. A preparation method of a thermal-oxidative-aging-resistant polyurethane elastomer material is characterized by comprising the following steps:

(1) adding isocyanate and hydroxyl-terminated butyronitrile into an organic solvent for mixing and prepolymerization to obtain a polyurethane prepolymer; the mixing and pre-polymerizing process is carried out under the conditions of nitrogen atmosphere, heating and stirring;

(2) dispersing carbon nanodots in the polyurethane prepolymer, heating and stirring to obtain a mixture;

(3) and adding a chain extender into the mixture, and vulcanizing to obtain the thermal-oxidative-aging-resistant polyurethane elastomer.

2. The method for preparing a thermal oxidative aging resistant polyurethane elastomer material according to claim 1, wherein the isocyanate in step (1) is any one selected from hexamethylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate; the organic solvent is xylene.

3. The method for preparing a thermal oxidative aging resistant polyurethane elastomer material according to claim 1, wherein the molar ratio of the isocyanate to the hydroxyl terminated liquid butyronitrile in step (1) is 2: 1; the mass volume ratio of the isocyanate to the organic solvent is 0.5-1.0 mg/ml.

4. The method for preparing a thermo-oxidative aging resistant polyurethane elastomer material as claimed in claim 1, wherein the heating temperature in step (1) is 70-80 ℃, and the stirring rate is 300-600 rpm/s; the prepolymerization time is 2-3 hours.

5. The method for preparing a thermo-oxidative aging resistant polyurethane elastomer material as claimed in claim 1, wherein the carbon nanodots in the step (2) are carbon nanodots having amino groups and hydroxyl groups on the surface.

6. The method for preparing a thermo-oxidative aging-resistant polyurethane elastomer material as claimed in claim 1, wherein the mass ratio of the carbon nano-dots to the polyurethane prepolymer in step (2) is 1: (100-200).

7. The method for preparing a thermo-oxidative aging resistant polyurethane elastomer material as claimed in claim 1, wherein the heating temperature in the step (2) is 70-80 ℃; the stirring time is 1-3 hours.

8. The method as claimed in claim 1, wherein the step (3) of adding the chain extender into the mixture, and curing the mixture in a flat vulcanizing press at 100-120 ℃ for 1-3 hours to obtain the thermo-oxidative aging-resistant polyurethane elastomer.

9. The method for preparing a thermo-oxidative aging resistant polyurethane elastomer material according to claim 8, wherein the chain extender is any one selected from ethylene glycol, diethylene glycol, 1, 2-propylene glycol, dipropylene glycol, and 1, 4-butanediol; the molar ratio of the chain extender to the isocyanate is 1: 2.

10. use of a thermo-oxidative aging resistant polyurethane elastomer material, characterized in that the thermo-oxidative aging resistant polyurethane elastomer material obtained by the preparation method according to any one of claims 1 to 9 is used as a protective jacket material for composite cables for industrial machinery equipment.

Technical Field

The invention relates to the technical field of polyurethane elastomer materials, in particular to a preparation method and application of a thermal-oxidative-aging-resistant polyurethane elastomer material.

Background art

The polyurethane elastomer has a special hard segment and soft segment alternate arrangement structure, so that the polyurethane elastomer has excellent wear resistance, excellent ozone resistance, high hardness, high strength, good elasticity, low temperature resistance, good oil resistance, chemical resistance and other excellent performances, and is widely applied to industries of national defense, medical treatment, food and the like. However, a large amount of unsaturated bonds are often introduced into the polyurethane elastomer in the synthesis process, and under the influence of factors such as illumination, temperature, oxygen, moisture and the like, the unsaturated bonds are broken to generate new free radicals, the free radicals are mutually crosslinked to react, and after aging, molecular chains are broken into small molecular chain segments to cause changes of relative molecular mass, crosslinking degree and crystallinity, so that the material is softened, the surface is sticky, air gaps are formed, and the service life of the elastomer is seriously reduced. At present, the most common solution in industry is to add amine and phenol small molecule anti-aging agents into the materials, and the small molecules mainly improve the aging resistance of the materials by capturing hydrocarbon peroxide radicals generated in the oxidation reaction process. However, these materials are highly toxic and volatile during use, and often collect on the surface of the elastomeric material and bloom, resulting in a reduction in the antioxidant effect. Therefore, it is of great significance to find an anti-aging agent which is safe, non-toxic and not easy to gather and bloom to replace a small molecular anti-aging agent.

Carbon nanodots are a new type of carbon nanomaterial, typically consisting of an internal carbon core and surface functional groups, typically less than 10nm in size. Compared with the traditional micromolecule anti-aging agent and nanoparticle material, the carbon nanoparticle has large carbon core and abundant easily-modified surface groups, can solve the problem of small molecule surface blooming, has the advantages of easy functionalization, simple preparation method, no pollution and the like, and can greatly improve the thermal oxidation resistance and aging resistance. However, the improvement of the thermal oxidation aging resistance of the polyurethane elastomer by using the carbon nanodots as the anti-aging agent is not reported at present.

Disclosure of Invention

The invention aims to provide a preparation method of a thermal-oxidative-aging-resistant polyurethane elastomer material, which is characterized in that carbon nanodots serving as novel anti-aging agents are compounded into the polyurethane elastomer material in situ for the first time, so that the thermal-oxidative-aging-resistant performance of the polyurethane elastomer is obviously improved, and the preparation method is simple and low in cost; the thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the invention is used as a protective sleeve material of an industrial robot cable, and can meet special performance tests of bending, torsion, radiation resistance and the like specified by the cable.

The invention is realized by the following technical scheme:

a preparation method of a thermal-oxidative-aging-resistant polyurethane elastomer material comprises the following steps:

(1) adding isocyanate and hydroxyl-terminated butyronitrile into an organic solvent for mixing and prepolymerization to obtain a polyurethane prepolymer; the mixing and pre-polymerizing process is carried out under the conditions of nitrogen atmosphere, heating and stirring;

(2) dispersing carbon nanodots in the polyurethane prepolymer, heating and stirring to obtain a mixture;

(3) and adding a chain extender into the mixture, and vulcanizing to obtain the thermal-oxidative-aging-resistant polyurethane elastomer. The invention takes carbon nanodots as an anti-aging agent.

Further, the isocyanate in the step (1) is selected from any one of hexamethylene diisocyanate, isophorone diisocyanate and xylylene diisocyanate; the organic solvent is xylene.

Further, the molar ratio of the isocyanate to the hydroxyl-terminated liquid butyronitrile in the step (1) is 2: 1; the mass volume ratio of the isocyanate to the organic solvent is 0.5-1.0 mg/ml.

Further, the heating temperature in the step (1) is 70-80 ℃, and the stirring speed is 300-600 revolutions per second; the prepolymerization time is 2-3 hours.

Further, the carbon nanodots in the step (2) are carbon nanodots with amino and hydroxyl groups on the surface. Preferably, amino, hydroxyl and other functional groups on the surface of the carbon nanodot are easy to chemically react with isocyanate groups, so that the defect that the small-molecule anti-aging agent is aggregated and frosted after being used for a long time is overcome.

Further, the mass ratio of the carbon nano-dots to the polyurethane prepolymer in the step (2) is 1: (100-200).

Further, the heating temperature in the step (2) is 70-80 ℃; the stirring time is 1-3 hours.

Further, in the step (3), a chain extender is added into the mixture, and then the mixture is cured for 1 to 3 hours in a flat vulcanizing machine at the temperature of 100 ℃ and 120 ℃ to obtain the thermal-oxidative aging resistant polyurethane elastomer.

Further, the chain extender is selected from any one of ethylene glycol, diethylene glycol, 1, 2-propylene glycol, dipropylene glycol and 1, 4-butanediol; the molar ratio of the chain extender to the isocyanate is 1: 2.

the thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the preparation method is used as a protective sleeve material of a comprehensive cable for industrial machine equipment. The thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the method has the excellent characteristics of high bending strength, good flexibility, wear resistance, sunlight aging resistance, halogen-free environmental protection, pollution resistance, radiation resistance and the like, and can meet special performance tests of bending, torsion, radiation resistance and the like specified by cables when used as a protective sleeve material of a comprehensive cable for industrial machinery equipment.

The invention has the beneficial effects that:

according to the thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the invention, the carbon nanodots serving as the novel anti-aging agents are compounded into the polyurethane elastomer material in situ for the first time, so that the thermal-oxidative-aging-resistant performance of the hydroxyl-terminated liquid butyronitrile type polyurethane elastomer is obviously improved, and the preparation method is simple and low in cost. Compared with the traditional micromolecular antioxidant, the carbon nanodots used in the invention have the characteristics of low preparation cost, low toxicity and the like, and functional groups such as amino groups, hydroxyl groups and the like on the surface of the carbon nanodots are easy to chemically react with isocyanate groups, so that the defect that the micromolecular antioxidant is aggregated and frosted after being used for a long time is avoided. The thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the invention has no obvious phenomena of cracks, aggregation and frosting after being kept at the temperature of 120 ℃ for 72 hours.

The thermal-oxidative-aging-resistant polyurethane elastomer material prepared by the method has the excellent characteristics of high bending strength, good flexibility, wear resistance, sunlight aging resistance, halogen-free environmental protection, pollution resistance, radiation resistance and the like, and can meet special performance tests of bending, torsion, radiation resistance and the like specified by cables when being used as a protective sleeve material of a comprehensive cable for industrial machinery equipment.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a scanning electron microscope image of a thermal-oxidative-aging-resistant polyurethane elastomer material prepared in example 1 of the present invention;

FIG. 2 is a scanning electron microscope image of a thermal oxidative aging resistant polyurethane elastomer material prepared in example 2 of the present invention after thermal oxidative aging;

FIG. 3 is a scanning electron microscope image of a hydroxyl-terminated liquid nitrile-butadiene type polyurethane elastomer material prepared in comparative example 1 of the present invention after thermo-oxidative aging;

fig. 4 is a schematic structural diagram of an integrated cable for industrial machine equipment in application example 1 of the present invention.

In the figure: the device comprises a power supply unit 1, a pair of twisting units 2, a measurement control unit 3, a bus unit 4, aramid yarns 5, an inner protective layer 6, a metal shielding layer 7, an inner protective sleeve I8, an inner protective sleeve II 9, a total shielding layer 10 and an outer protective sleeve 11.

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. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. 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.

Example 1

A preparation method of a thermal-oxidative-aging-resistant polyurethane elastomer material comprises the following steps:

(1) under the conditions of nitrogen atmosphere, 80 ℃ and mechanical stirring, adding isophorone diisocyanate and hydroxyl-terminated butyronitrile into a xylene solution for mixing and prepolymerization for 2 hours to obtain a polyurethane prepolymer; and the rate of mechanical agitation is 300 revolutions per second; the molar ratio of the isophorone diisocyanate to the hydroxyl-terminated liquid butyronitrile is 2: 1; the mass volume ratio of the isophorone diisocyanate to the xylene solution is 0.5 mg/ml;

(2) dispersing carbon nanodots (anti-aging agents) containing amino and hydroxyl in the polyurethane prepolymer, heating to 80 ℃, and mechanically stirring for 2 hours to obtain a mixture; and the mass ratio of the carbon nano-points containing amino and hydroxyl to the polyurethane prepolymer is 1: 100, respectively;

(3) then adding 1, 4-butanediol (chain extender) into the obtained mixture, uniformly stirring, and then pouring into a flat vulcanizing machine at 120 ℃ for curing for 3 hours to obtain the thermal-oxidative aging resistant polyurethane elastomer material; and the molar ratio of the 1, 4-butanediol to the isophorone diisocyanate is 1: 2.

example 2

A preparation method of a thermal-oxidative-aging-resistant polyurethane elastomer material comprises the following steps:

(1) adding hexamethylene diisocyanate and hydroxyl-terminated butyronitrile into a xylene solution in a nitrogen atmosphere at the temperature of 70 ℃ under the condition of mechanical stirring for mixing and prepolymerization for 3 hours to obtain a polyurethane prepolymer; and the speed of the mechanical stirring is 600 revolutions per second; the molar ratio of the hexamethylene diisocyanate to the hydroxyl-terminated liquid butyronitrile is 2: 1; the mass-to-volume ratio of the hexamethylene diisocyanate to the xylene solution is 0.8 mg/ml;

(2) dispersing carbon nanodots containing amino and hydroxyl in the polyurethane prepolymer, heating to 70 ℃, and mechanically stirring for 1 hour to obtain a mixture; and the mass ratio of the carbon nano-points containing amino and hydroxyl to the polyurethane prepolymer is 1: 150;

(3) then adding diethylene glycol (a chain extender) into the obtained mixture, uniformly stirring, and then pouring into a flat vulcanizing machine at 100 ℃ for curing for 2 hours to obtain the thermal-oxidative-aging-resistant polyurethane elastomer material; and the mole ratio of the diethylene glycol (diethylene glycol) to the hexamethylene diisocyanate is 1: 2.

example 3

A preparation method of a thermal-oxidative-aging-resistant polyurethane elastomer material comprises the following steps:

(1) under the conditions of nitrogen atmosphere, 75 ℃ and mechanical stirring, adding xylylene diisocyanate and hydroxyl-terminated butyronitrile into a xylene solution for mixing and prepolymerization for 3 hours to obtain a polyurethane prepolymer; and the speed of the mechanical stirring is 500 revolutions per second; the molar ratio of the xylylene diisocyanate to the hydroxyl-terminated liquid butyronitrile is 2: 1; the mass-volume ratio of the xylylene diisocyanate to the xylene solution is 1.0 mg/ml;

(2) dispersing carbon nanodots containing amino and hydroxyl in the polyurethane prepolymer, heating to 70 ℃, and mechanically stirring for 1 hour to obtain a mixture; and the mass ratio of the carbon nano-points containing amino and hydroxyl to the polyurethane prepolymer is 1: 200 of a carrier;

(3) then adding ethylene glycol (chain extender) into the obtained mixture, uniformly stirring, and then pouring into a flat vulcanizing machine at the temperature of 110 ℃ for curing for 1 hour to obtain the thermal-oxidative-aging-resistant polyurethane elastomer material; and the molar ratio of the ethylene glycol to the xylylene diisocyanate is 1: 2.

comparative example 1

The hydroxyl-terminated liquid butyronitrile type polyurethane elastomer material is prepared by adopting the traditional amine and phenol micromolecules as the anti-aging agent, the difference between the comparative example 1 and the example 1 is that the anti-aging agent used in the example 1 is carbon nanodots containing amino and hydroxyl, the anti-aging agent used in the comparative example 1 is the amine and phenol micromolecules, and the rest preparation conditions of the comparative example 1 are the same as those of the example 1.

Test example 1

The thermo-oxidative aging resistant polyurethane elastomer material prepared in example 1 is characterized by a Scanning Electron Microscope (SEM), and the result is shown in fig. 1, in which it can be seen that the carbon nanodots are uniformly dispersed in the polyurethane elastomer.

Test example 2

The thermal oxidative aging resistant polyurethane elastomer material prepared in the above example 2 is taken, placed in a thermal oxidative aging box at room temperature for 48 hours, then subjected to thermal oxidative aging at 120 ℃ for 48 hours, and then characterized by a Scanning Electron Microscope (SEM), and the result is shown in fig. 2, and it can be seen from fig. 2 that the polyurethane elastomer material has no obvious cracks and aggregation and frosting phenomena on the surface.

Test example 3

The hydroxyl-terminated liquid butyronitrile type polyurethane elastomer material prepared in the comparative example 1 is taken, placed for 48 hours at room temperature, then placed in a thermo-oxidative aging box for thermo-oxidative aging for 48 hours at 120 ℃, and then characterized by a Scanning Electron Microscope (SEM), and the result is shown in FIG. 3, and the phenomenon of obvious cracks and aggregation and frosting on the surface of the polyurethane elastomer material can be seen from FIG. 3.

The test examples 2-3 show that the polyurethane elastomer added with the carbon nanodots has no obvious phenomena of cracks and aggregation frosting and has better thermo-oxidative aging resistance compared with the polyurethane elastomer not added with the carbon nanodots after thermo-oxidative aging for 48 hours at 120 ℃.

Application example 1

The thermal oxidative aging resistant polyurethane elastomer material prepared in the above example 1 is used as a protective jacket material of a composite cable for industrial equipment, and specifically comprises the following steps:

as shown in fig. 4, the composite cable for industrial machine equipment includes a cable core composed of a 3-wire power supply unit 1, two twisted pairs 2, two 4-wire star-twisted measurement control units 3, and a twisted pair data transmission field bus unit 4, and a protective material disposed outside the cable core (the protective material includes an inner protective sleeve two 9, a total shielding layer 10, and an outer protective sleeve 11). And the twisted clearance of each unit wire core is filled and rounded by aramid yarn 5, and then the aramid yarn is wound around a polytetrafluoroethylene wrapping tape to form an inner protection layer 6 of each unit group; in order to improve the accuracy of signal and data acquisition and transmission and reduce the influence of electromagnetic compatibility on the performance of products, metal shielding layers 7 are arranged on the outer sides of the inner protection layers 6 on each unit group (the metal shielding layers 7 adopt a double-layer shielding structure woven by aluminum foils and tinned copper wires); then, extruding and wrapping a thermal-oxidative-aging-resistant polyurethane elastomer material on the outer side of the metal shielding layer 7 on each unit group to serve as a first inner protective sleeve 8; then aramid yarns 5 are added in the stranding gaps of the unit groups to form a comprehensive cable core for the industrial machine equipment (the cable core is composed of a 3-line power supply unit 1, two pair-twisting groups 2, two 4-line star-twisting group measurement control units 3, a data transmission field bus unit 4 of the pair-twisting group, the aramid yarns 5, an inner protection layer 6, a metal shielding layer 7 and an inner protection sleeve I8), and then a polytetrafluoroethylene tape is wound outside the comprehensive cable core for the industrial machine equipment to form an inner protection sleeve II 9 of the comprehensive cable for the industrial machine equipment; and then weaving a tinned soft copper wire outside the inner protective sleeve II 9 to form a total shielding layer 10 of the comprehensive cable for industrial machine equipment, and finally extruding and coating a layer of thermal-oxidative-aging-resistant polyurethane elastomer material outside the total shielding layer 10 to form an integral outer protective sleeve 11 of the cable.

The protective sleeve and the total outer sheath of each unit of the comprehensive cable for the industrial machine equipment are made of extruded thermal-aging-resistant polyurethane elastomer materials, and the thermal-aging-resistant polyurethane elastomer material has the excellent characteristics of high bending strength, good flexibility, wear resistance, sunlight aging resistance, halogen-free environment friendliness, pollution resistance, radiation resistance and the like, and can meet special performance tests of bending, twisting, radiation resistance and the like specified by the cable.

The above-mentioned preferred embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention. Obvious variations or modifications of the present invention are within the scope of the present invention.