High-performance environment-friendly MDI-based TPU elastic plastic

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a high-performance environment-friendly MDI-based TPU (thermoplastic polyurethane) elastic plastic, which is prepared by polymerizing the following components in percentage by mass: 30-40% of 4, 4 '-diphenylmethane diisocyanate, 10-20% of diphenylmethane diisocyanate, 10-20% of diphenylmethane diisocyanate, 10-20% of diphenylmethane diisocyanate, 20-25% of adipic acid; 15 to 20 percent of 1, 4-butanediol; 2-5% of a chain extender; 2-5% of a chain extender; 2-5% of a chain extender; and 5-10% of a grafted and modified polyolefin high polymer material, the grafting ratio of polyolefin to maleic anhydride being 1: 0.05-0.1, and the like. The high-performance environment-friendly MDI-based TPU elastic plastic provided by the invention has excellent mechanical properties, heat resistance, chemical corrosion resistance and environmental friendliness by optimizing the proportion and a grafting modification technology, the comprehensive performance is improved and the environmental pollution is reduced by adopting the bio-based PBS and the grafting modified polyolefin, and the weather resistance is enhanced by adding the ultraviolet light absorber. The plastic is widely applied to the fields of automobiles, shoe materials, sports equipment and the like, and has remarkable social and economic benefits and market value.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to a high-performance, environment-friendly MDI-based TPU elastic plastic. Background Art

[0002] As an important polymer material, thermoplastic polyurethane (TPU) has been widely used in many fields such as footwear, automotive parts, wires and cables, and medical equipment due to its excellent elasticity, wear resistance, oil resistance, and chemical resistance. However, traditional TPU materials often have problems such as environmental pollution, high resource consumption, and single performance during the preparation process. Especially in the field of footwear, its weather resistance, environmental protection, and processing performance still need to be improved. Specifically, the commonly used isocyanate raw materials in traditional TPU shoe materials may contain free isocyanate monomers that are harmful to the human body, and volatile organic compounds (VOCs) are easily generated during the production process, causing environmental pollution. In addition, traditional TPU materials are deficient in aging resistance and UV resistance. They are prone to yellowing and cracking when exposed to outdoor environments for a long time, affecting the service life and aesthetics of the product. At the same time, the processing performance of traditional TPU materials also limits their application in shoe parts with complex shapes. In response to the above problems, the industry has been exploring more environmentally friendly and high-performance TPU materials. Among them, MDI (4,4'-diphenylmethane diisocyanate), as an important isocyanate raw material, is widely used in the preparation of high-performance TPU materials due to its symmetrical molecular structure, high reactivity and good product performance. However, how to optimize the components of MDI-based TPU materials to improve their environmental protection, weather resistance and processing performance is still a hot topic and difficulty in current research. Summary of the invention

[0003] 1. Technical issues to be resolved The present invention aims to provide a high-performance, environmentally friendly MDI-based TPU elastic plastic to solve the deficiencies of existing TPU materials in terms of environmental protection, weather resistance and processing performance. By optimizing the component ratio and introducing specific additives, the present invention aims to improve the environmental performance of TPU materials, enhance their weather resistance and UV resistance, and improve their processing performance to meet the demand for high-performance, environmentally friendly TPU materials in the field of shoe materials and the like.

[0004] (II) Technical solution The present invention is implemented by the following technical solution: The present invention proposes a high-performance, environmentally friendly MDI-based TPU elastic plastic, which is polymerized by the following mass fractions of components: 4,4'-diphenylmethane diisocyanate: 30-40%; Adipic acid: 20-25%; 1,4-Butanediol: 15-20%; Chain extender: 2-5%; Catalyst: 0.1-0.5%; Hindered phenol antioxidant: 0.5-1%; and graft-modified polyolefin polymer material: 5-10%, wherein the graft ratio of polyolefin to maleic anhydride is 1:0.05-0.1; Bio-based polybutylene succinate: 5-10%.

[0005] Preferably, the polyolefin polymer material is polyethylene or polypropylene, and its molecular weight is 10,000-50,000 g / mol.

[0006] Preferably, the chain extender is at least one of 1,4-butanediol chain extender, ethylene glycol chain extender or trimethylolpropane chain extender.

[0007] Preferably, the catalyst is at least one of an organotin catalyst, a dimethylaminopyridine catalyst or an organobismuth catalyst.

[0008] Preferably, the molar ratio of 4,4'-diphenylmethane diisocyanate, adipic acid and 1,4-butanediol is 2:1.5:1.2.

[0009] Preferably, the hindered phenol antioxidant is any one or more of 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

[0010] Preferably, the plastic further contains an ultraviolet absorber, the added amount of which is 0.1-0.5% of the total mass of the plastic.

[0011] (III) Beneficial effects Compared with the prior art, the present invention has the following beneficial effects: the present invention proposes a high-performance environmentally friendly MDI-based TPU elastic plastic, and through precise control of the raw material ratio and the use of environmentally friendly grafting modification technology, a new type of plastic with excellent mechanical properties, heat resistance, chemical corrosion resistance, environmental protection, processing performance and weather resistance is prepared. The plastic uses MDI, adipic acid, and 1,4-butanediol as the main raw materials, supplemented by chain extenders, catalysts, hindered phenol antioxidants and bio-based PBS, and introduces grafted modified polyolefin polymer materials, which significantly improves the comprehensive performance of the plastic. The plastic not only meets environmental protection requirements and reduces environmental pollution, but also has a wide range of application prospects, and can be used in automotive interiors, shoe materials, sports equipment, wire and cable sheaths, medical devices and other fields. . DETAILED DESCRIPTION

[0012] In this technical solution: In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0013] The present invention provides a high-performance, environmentally friendly MDI-based TPU elastic plastic, which is polymerized by the following components in mass fractions: 4,4'-diphenylmethane diisocyanate: 30-40%; Adipic acid: 20-25%; 1,4-Butanediol: 15-20%; Chain extender: 2-5%; Catalyst: 0.1-0.5%; Hindered phenol antioxidant: 0.5-1%; and graft-modified polyolefin polymer material: 5-10%, wherein the graft ratio of polyolefin to maleic anhydride is 1:0.05-0.1; Bio-based polybutylene succinate: 5-10%.

[0014] Wherein, the polyolefin polymer material is polyethylene or polypropylene, and its molecular weight is 10,000-50,000 g / mol.

[0015] Wherein, the chain extender is at least one of 1,4-butanediol chain extender, ethylene glycol chain extender or trimethylolpropane chain extender.

[0016] Wherein, the catalyst is at least one of an organic tin catalyst, a dimethylaminopyridine catalyst or an organic bismuth catalyst.

[0017] Wherein, the molar ratio of the 4,4'-diphenylmethane diisocyanate, adipic acid and 1,4-butanediol is 2:1.5:1.2.

[0018] The hindered phenol antioxidant is any one or more of 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

[0019] The plastic also contains an ultraviolet absorber, the added amount of which is 0.1-0.5% of the total mass of the plastic.

[0020] The production process of the elastic plastic includes the following key steps: raw material preparation, grafting modification of polyolefins, synthesis of prepolymers, chain extension reaction, post-treatment and molding processing, the steps are as follows: Raw material preparation: Accurately weigh all raw materials according to the formula ratio, including 4,4'-diphenylmethane diisocyanate (MDI), adipic acid, 1,4-butanediol, chain extender, catalyst, hindered phenol antioxidant, graft-modified polyolefin polymer material (polyethylene or polypropylene), bio-based polybutylene succinate (PBS) and optional UV absorber; Graft modification of polyolefins: polyethylene or polypropylene of selected molecular weight is mixed with maleic anhydride in a ratio of 1:0.05-0.1. In a molten state, a grafting reaction is initiated by a free radical initiator (such as dibenzoyl peroxide) to graft maleic anhydride onto the polyolefin molecular chain. After the grafting reaction is completed, the grafted polyolefin polymer material is obtained by cooling, washing and drying; Synthesis of prepolymer: MDI, adipic acid and 1,4-butanediol are added into a reactor at a molar ratio of 2:1.5:1.2, heated to a suitable temperature (e.g. 80-100°C) under the protection of inert gas, and a catalyst (e.g. an organic tin catalyst) is added to start polymerization reaction. After the prepolymer reaches the desired viscosity, heating is stopped and cooled to room temperature; Chain extension reaction: Mix the prepolymer with the chain extender (such as 1,4-butanediol chain extender), hindered phenol antioxidant, graft-modified polyolefin polymer material and bio-based PBS evenly, heat it to a suitable temperature again, add the remaining catalyst, carry out the chain extension reaction, monitor the reaction process, ensure that the chain extension reaction is complete, and obtain a high molecular weight TPU elastic plastic; Post-treatment: After the reaction is completed, the product is cooled to room temperature, and unreacted raw materials and impurities are removed by filtering, washing and drying. If necessary, ultraviolet absorbers can be added to improve the weather resistance of the plastic; Molding: The treated TPU elastic plastic is processed into the required shape and size through molding processes such as injection molding, extrusion or calendering.

[0021] The present invention precisely controls the molar ratio of 4,4'-diphenylmethane diisocyanate (MDI), adipic acid and 1,4-butanediol, and reasonably selects a chain extender and a catalyst. The TPU elastic plastic prepared by the present invention has high strength, high elongation at break and suitable hardness, and can meet the requirements of various application scenarios for mechanical properties. The bio-based polybutylene succinate (PBS) introduced in the present invention not only improves the environmental friendliness of the plastic, but also enhances its heat resistance and chemical corrosion resistance. At the same time, the grafted modified polyolefin polymer material (polyethylene or polypropylene) further improves the weather resistance and chemical stability of the plastic. The PBS in the present invention is a bio-based material derived from renewable resources, which reduces the dependence on fossil fuels and reduces carbon emissions. In addition, the grafting modification process of polyolefins also adopts environmentally friendly grafting technology and catalysts, ensuring the greenness and environmental protection of the entire production process. By optimizing the formula and process conditions, the TPU elastic plastic prepared by the present invention has excellent processing performance, and is easy to be processed into products of various shapes and sizes through molding processes such as injection molding and extrusion, and is not prone to defects such as mold sticking and bubbles during the processing; Since the high-performance and environmentally friendly MDI-based TPU elastic plastic of the present invention has excellent mechanical properties, heat resistance, chemical corrosion resistance, environmental protection, processing performance and weather resistance, it has broad application prospects, such as automotive interiors, shoe materials, sports equipment, wire and cable sheaths, medical equipment and other fields. Example 1

[0022] Formula: MDI 35%, adipic acid 22.5%, 1,4-butanediol 17.5%, 1,4-butanediol chain extender 3%, dimethylaminopyridine catalyst 0.3%, 2,6-di-tert-butyl-4-methylphenol antioxidant 0.7%, grafted modified polyethylene (molecular weight 30,000g / mol, grafting ratio 1:0.075) 7.5%, bio-based PBS 7.5%, UV absorber 0.3%; Production process: According to the above production process, the grafting reaction is carried out at 120°C for 2 hours, the prepolymer synthesis is carried out at 90°C for 4 hours, and the chain extension reaction is carried out at 100°C for 2 hours; Product performance: The obtained TPU elastic plastic has excellent mechanical properties, weather resistance and environmental protection, and is suitable for automotive interiors, shoe materials, sports equipment and other fields. Example 2

[0023] Formula: MDI 30%, adipic acid 25%, 1,4-butanediol 15%, ethylene glycol chain extender 4%, organic bismuth catalyst 0.2%, tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol antioxidant 0.5%, grafted modified polypropylene (molecular weight 40,000g / mol, grafting ratio 1:0.1) 10%, bio-based PBS 5%, ultraviolet absorber 0.5%; Production process: According to the above production process, the grafting reaction is carried out at 130°C for 1.5 hours, the prepolymer synthesis is carried out at 85°C for 5 hours, and the chain extension reaction is carried out at 95°C for 3 hours; Product performance: The obtained TPU elastic plastic has higher heat resistance and chemical corrosion resistance, and is suitable for wire and cable sheaths, medical devices and other fields.

[0024] Comparative Example: Formula: MDI 25%, adipic acid 30%, 1,4-butanediol 25%, conventional diol chain extender 6%, organotin catalyst 0.2%, hindered phenol antioxidant (unspecified type) 0.3%, ungrafted polyethylene 10%, polybutylene succinate (non-biobased) 10%, no UV absorber Production process: MDI, adipic acid and 1,4-butanediol are put into a reactor according to the formula ratio, heated to a suitable temperature, and an organic tin catalyst is added to start the polymerization reaction; after the prepolymer reacts to reach the required viscosity, a conventional diol chain extender and a hindered phenol antioxidant are added to continue the reaction for chain extension; ungrafted modified polyethylene and polybutylene succinate are added to the reaction system and mixed evenly; after the reaction is completed, the product is cooled to room temperature, and the unreacted raw materials and impurities are removed by filtering, washing and drying; the treated TPU elastic plastic is processed into the required shape and size by molding processes such as injection molding.

[0025] The comparison of key performance parameters between Example 1, Example 2 and the comparative example is shown in the following table:

[0026] Comparison conclusion: Tensile strength and elongation at break: The TPU elastic plastics of Example 1 and Example 2 are superior to those of the comparative example in terms of tensile strength and elongation at break, which is mainly due to the graft-modified polyolefin polymer material and the optimized formula ratio; Hardness: The hardness of Example 1 and Example 2 is slightly higher than that of the comparative example, which helps to improve the wear resistance and scratch resistance of the product; Heat resistance: Example 2 has the highest heat resistance, reaching 220°C, which is mainly due to its higher MDI content and optimized chain extension reaction conditions; the heat resistance of Example 1 is also better than that of the comparative example; Chemical corrosion resistance: Both Example 1 and Example 2 exhibit excellent chemical corrosion resistance, which is due to the introduction of bio-based PBS and graft-modified polyolefin polymer materials; Weather resistance: After UV aging test, the tensile strength retention rates of Example 1 and Example 2 are higher than that of the comparative example, which is mainly due to the addition of UV absorber and the contribution of graft-modified polyolefin polymer materials; Environmental protection: Examples 1 and 2 both contain a high proportion of bio-based materials, which meet environmental protection requirements; while the comparative example uses only non-bio-based materials; Processing performance: Examples 1 and 2 both exhibit good processing performance and are easily processed into products of various shapes and sizes; however, the comparative example has the problem of easy mold sticking; In summary, the high-performance and environment-friendly MDI-based TPU elastic plastics of Examples 1 and 2 are superior to those of the comparative example in various performance parameters and have broader application prospects.

[0027] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. It should be noted that the above is only a specific example of the present invention. Obviously, the present invention is not limited to the above examples, and there may be many variations. All variations that can be directly derived or associated with the content disclosed by a person of ordinary skill in the art from the present invention should be considered as the protection scope of the present invention.

Claims

1. A high-performance, environmentally friendly MDI-based TPU elastic plastic, characterized in that: The plastic is polymerized by the following mass fractions: 4,4'-diphenylmethane diisocyanate: 30-40%; Adipic acid: 20-25%; 1,4-Butanediol: 15-20%; Chain extender: 2-5%; Catalyst: 0.1-0.5%; Hindered phenol antioxidant: 0.5-1%; and graft-modified polyolefin polymer material: 5-10%, wherein the graft ratio of polyolefin to maleic anhydride is 1:0.05-0.1; Bio-based polybutylene succinate: 5-10%.

2. A high-performance, environmentally friendly MDI-based TPU elastic plastic according to claim 1, characterized in that: The polyolefin polymer material is polyethylene or polypropylene, and its molecular weight is 10,000-50,000 g / mol.

3. The high-performance, environmentally friendly MDI-based TPU elastic plastic according to claim 1, characterized in that: The chain extender is at least one of 1,4-butanediol chain extender, ethylene glycol chain extender or trimethylolpropane chain extender.

4. The high-performance, environmentally friendly MDI-based TPU elastic plastic according to claim 1, characterized in that: The catalyst is at least one of an organic tin catalyst, a dimethylaminopyridine catalyst or an organic bismuth catalyst.

5. The high-performance, environmentally friendly MDI-based TPU elastic plastic according to claim 1, characterized in that: The molar ratio of the 4,4'-diphenylmethane diisocyanate, adipic acid and 1,4-butanediol is 2:1.5:1.

2.

6. The high-performance, environmentally friendly MDI-based TPU elastic plastic according to claim 1, characterized in that: The hindered phenol antioxidant is any one or more of 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

7. The high-performance, environmentally friendly MDI-based TPU elastic plastic according to claim 1, characterized in that: The plastic also contains an ultraviolet absorber, the added amount of which is 0.1-0.5% of the total mass of the plastic.

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