A kind of thermoplastic polyurethane and its preparation method and application

Abstract

The invention discloses a thermoplastic polyurethane and a preparation method and application thereof. The thermoplastic polyurethane is prepared by comprising the following raw materials: 30-80 parts by mass of polyol; 0.01-10 parts by mass of modified adamantane alcohol; 20-50 parts by mass of diisocyanate; and 3-17 parts by mass of diol chain extender. The method of the invention obtains a thermoplastic polyurethane having excellent transparency and demoulding properties.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane preparation, and in particular to a thermoplastic polyurethane and a preparation method and application thereof. Background Art

[0002] Thermoplastic polyurethane elastomer (TPU) is a polymer composed of flexible soft segments and rigid hard segments. It has rubber elasticity at low temperatures and can be plasticized and formed at elevated temperatures. TPU has excellent mechanical properties, such as a wide range of adjustable hardness, high mechanical strength, good wear resistance, toughness, excellent oil resistance, shock absorption and radiation resistance, good processing performance, and a wide range of uses. Its use range is becoming increasingly wider. Products with high hardness will increase the haze of the material and deteriorate its transparency due to the crystallization of the soft and hard segments. The introduction of side groups to destroy the crystallization of the soft segment will cause the product molding to deteriorate.

[0003] In addition, polyurethane, as a polar material, has high requirements for demoulding properties. Especially in the process of mass injection molding, mold sticking will extend the production cycle and affect production efficiency. Lubricating wax is widely used in TPU products to improve demoulding properties, but the addition of lubricating wax will cause product precipitation or affect product transparency.

[0004] The Chinese invention patent with application number 201410478067.6 discloses a transparent barrier thermoplastic polyurethane elastomer and a preparation method thereof, wherein thermoplastic polyurethane, K glue, inorganic filler and barrier agent are added to ensure that the prepared polyurethane elastomer has good transparency and gas and water vapor barrier properties. However, it is based on the synthesized polyurethane material and achieves good transparency by adding barrier agents and additives to improve transparency. This is different from optimizing the polyurethane material itself to obtain a material with higher transparency. Summary of the invention

[0005] In view of this, the main purpose of the present invention is to provide a thermoplastic polyurethane having excellent transparency and demoulding properties, and a preparation method and application thereof.

[0006] To achieve the above-mentioned object of the invention, the first aspect of the present invention provides a thermoplastic polyurethane prepared by the following raw materials:

[0007] 30-80 parts by weight of polyol; 0.01-10 parts by weight of modified adamantane alcohol; 20-50 parts by weight of diisocyanate; 3-17 parts by weight of diol chain extender; the modified adamantane alcohol has the following structural formula:

[0008]

[0009] Where R 1 and R 2The alkyl radicals are independently selected from straight or branched chain alkyl radicals having 1 to 20 carbon atoms.

[0010] In a preferred embodiment, the thermoplastic polyurethane is prepared from the following raw materials:

[0011] 40-70 parts by weight of polyol; 0.1-5 parts by weight of modified adamantane alcohol; 24-46 parts by weight of diisocyanate; 5-15 parts by weight of diol chain extender.

[0012] In a preferred embodiment, the thermoplastic polyurethane is prepared from the following raw materials:

[0013] 50-65 parts by weight of polyol; 0.2-2 parts by weight of modified adamantane alcohol; 27-39 parts by weight of diisocyanate; 7-12 parts by weight of diol chain extender. Different proportions of the above raw materials will affect the transparency and demoulding properties of thermoplastic polyurethane. Within the above preferred proportion range, better transparency and demoulding properties can be achieved.

[0014] In a preferred embodiment, the structural formula of the modified adamantane alcohol is 1 and R 2 The alkyl radicals are independently selected from straight or branched chain alkyl radicals having 5 to 16, preferably 8 to 10 carbon atoms.

[0015] In a preferred embodiment, the preparation method of the modified adamantane alcohol is as follows: 1 mol of 1,3,5-adamantantriol and 2-2.2 mol of n-octanoic acid and optionally n-nonanoic acid are dissolved in an organic solvent to obtain a 1,3,5-adamantantriol solution, an n-octanoic acid solution and optionally a n-nonanoic acid solution, respectively; EDC·HCl and DMAP are added as catalysts to the n-octanoic acid solution and optionally the n-nonanoic acid solution; after dissolution, they are added to the 1,3,5-adamantantriol solution heated to 60-65° C.; react for 4-6 hours under inert gas protection; separate and collect the liquid; remove the solvent to obtain a solid, i.e., the modified adamantane alcohol.

[0016] In a preferred embodiment, the polyol is one of polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol or a combination thereof.

[0017] Preferably, the number average molecular weight of the polyol is 500-6000 g / mol, more preferably 1000-3000 g / mol.

[0018] In a preferred embodiment, the diisocyanate is selected from one or more of aromatic diisocyanates, aliphatic diisocyanates and alicyclic diisocyanates, preferably highly symmetrical aromatic diisocyanates, which are beneficial to improving the transparency and demolding properties of thermoplastic polyurethane products, such as MDI, HMDI, etc.

[0019] In a preferred embodiment, the diol chain extender is: aliphatic small molecule diol, the general formula is HO-C a H 2a -OH, a=a natural number from 1 to 10, preferably a=4.

[0020] The second aspect of the present invention provides a method for preparing thermoplastic polyurethane, wherein the polyol, modified adamantane alcohol, diisocyanate and chain extender as described above are uniformly mixed, and thermoplastic polyurethane is prepared by reaction extrusion.

[0021] In a preferred embodiment, the extrusion temperature of the reactive extrusion is 80-240°C, and the preferred suitable extrusion temperature of the above raw materials is 120-220°C.

[0022] The third aspect of the present invention provides a thermoplastic polyurethane or an application of the thermoplastic polyurethane prepared by the above method for preparing films or sheets in the automotive, medical, clothing, electronic and optical fields that have high requirements for transparency and rigidity.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] The invention uniformly mixes polyol, modified adamantane alcohol, diisocyanate and chain extender, and prepares thermoplastic polyurethane through reaction extrusion. By selecting the above raw materials, the invention can bond the adamantane group with a large volume and a highly symmetrical three-dimensional structure in the modified adamantane alcohol to the main chain of the polyurethane, which is conducive to realizing a high free volume in the molecule and improving the optical transparency in the visible light region. Meanwhile, the introduction of a large number of adamantane groups will cause the molecular arrangement inside the material to be not dense, affecting the material molding and thus affecting the demoulding of the product. The adamantane group in the modified adamantane alcohol selected by the invention is modified by a long carbon chain structure, and the regular and orderly structure and low polarity thereof can be used to reduce the adhesion of the material, thereby improving the demoulding performance of the product. Meanwhile, the bonding action of the hydroxyl group on the adamantane is used to control the precipitation of the demoulding component, thereby improving the demoulding performance of the polyurethane product.

[0025] Other features and advantages of the present invention will be described in detail through the following detailed description. DETAILED DESCRIPTION

[0026] The present application is further described below in conjunction with embodiments, but the present application is not limited to the listed embodiments, but also includes equivalent improvements and modifications of the technical solutions defined in the claims attached to the present application.

[0027] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0028] Certain specific steps involved in the experimental methods used in the following examples are routine operations unless otherwise specified.

[0029] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0030] Main raw material sources:

[0031] The BDO (1,4-butanediol), MDI (diphenylmethane diisocyanate), HMDI (4,4-dicyclohexylmethane diisocyanate), PBA (polybutylene adipate), and NPG-PCL (neopentyl glycol initiated polycaprolactone diol) used in the examples of the present invention are all produced by Wanhua Chemical Group Co., Ltd.

[0032] Performance test description:

[0033] The performance tests of thermoplastic polyurethane elastomer are as follows: light transmittance and haze are tested according to GB / T 2410-2008 standard; the molding cycle is characterized by the actual injection molding time of a smooth, full and non-broken gate test piece.

[0034] Modified Adamantane Alcohol Preparation Example 1:

[0035] 1 mol of 1,3,5-adamantantriol and 2 mol of n-octanoic acid were dissolved in cyclohexane and stirred to dissolve. A certain amount of EDC·HCl and DMAP were added to the n-octanoic acid solution in sequence. After stirring and dissolving, the mixture was added dropwise to the 1,3,5-adamantantriol solution at 60°C. 2 The reaction was carried out in an atmosphere for 4-6 hours. The liquid was separated and collected, and the solvent was removed to obtain a white solid, i.e., modified adamantane alcohol A.

[0036] Modified Adamantane Alcohol Preparation Example 2:

[0037] 1 mol of 1,3,5-adamantantriol and 1.1 mol of n-octanoic acid and 1.1 mol of n-nonanoic acid were dissolved in cyclohexane and stirred to dissolve. A certain amount of EDC·HCl and DMAP were added to the mixed solution of n-octanoic acid and n-nonanoic acid in sequence. After stirring and dissolving, the mixture was added dropwise to the 65°C 1,3,5-adamantantriol solution. 2The reaction was carried out in an atmosphere for 4-6 hours. The liquid was separated and collected, and the solvent was removed to obtain a white solid, i.e., modified adamantane alcohol B.

[0038] Example 1

[0039] 59.88wt% PBA (polybutylene adipate) with a molecular weight of 2000g / mol, 8.48wt% BDO (1,4-butanediol), 31.44wt% MDI (diphenylmethane diisocyanate), and 0.20wt% modified adamantane alcohol A were mixed uniformly, subjected to twin-screw reaction extrusion (extruder temperature 120°C to 210°C, die head temperature 220°C), and then underwater pelletization to obtain thermoplastic polyurethane.

[0040] Example 2

[0041] 29.85wt% NPG-PCL (neopentyl glycol initiated polycaprolactone diol) with a molecular weight of 2000g / mol, 17.31wt% BDO (1,4-butanediol), 52.14wt% MDI (diphenylmethane diisocyanate), and 0.50wt% modified adamantane alcohol A were mixed uniformly, extruded by a twin-screw reaction (extruder temperature 120°C to 210°C, die head temperature 220°C), and then pelletized underwater to obtain thermoplastic polyurethane.

[0042] Example 3

[0043] 59.88wt% of PBA (polybutylene adipate) with a molecular weight of 2000g / mol, 8.08wt% of BDO (1,4-butanediol), 31.83wt% of HMDI (4,4-dicyclohexylmethane diisocyanate), and 0.2wt% of modified adamantane alcohol A were mixed uniformly, subjected to twin-screw reaction extrusion (extruder temperature 120°C to 210°C, die head temperature 220°C), and then underwater pelletization to obtain thermoplastic polyurethane.

[0044] Example 4

[0045] 59.70wt% NPG-PCL (neopentyl glycol initiated polycaprolactone diol) with a molecular weight of 2000g / mol, 9.83wt% HDO (1,6-hexanediol), 29.97wt% HMDI (4,4-dicyclohexylmethane diisocyanate), and 0.50wt% modified adamantane alcohol A were mixed uniformly, subjected to twin-screw reaction extrusion (extruder temperature 120°C to 210°C, die head temperature 220°C), and then underwater pelletization to obtain thermoplastic polyurethane.

[0046] Example 5

[0047] 58.8wt% PBA (polybutylene adipate) with a molecular weight of 2000g / mol, 8.33wt% BDO (1,4-butanediol), 30.87wt% MDI (diphenylmethane diisocyanate), and 2.0wt% modified adamantane alcohol A were mixed uniformly, subjected to twin-screw reaction extrusion (extruder temperature 120°C to 210°C, die head temperature 220°C), and then underwater pelletization to obtain thermoplastic polyurethane.

[0048] Example 6

[0049] 29.94wt% NPG-PCL (neopentyl glycol initiated polycaprolactone diol) with a molecular weight of 1000g / mol, 16.37wt% BDO (1,4-butanediol), 53.49wt% MDI (diphenylmethane diisocyanate), and 0.20wt% modified adamantane alcohol B were mixed uniformly, extruded by a twin-screw reaction (extruder temperature 120°C to 200°C, die head temperature 230°C), and then pelletized underwater to obtain thermoplastic polyurethane.

[0050] Example 7

[0051] 69.65wt% PBA (polybutylene adipate) with a molecular weight of 3000g / mol, 3.21wt% BDO (1,4-butanediol), 26.63wt% MDI (diphenylmethane diisocyanate), and 0.50wt% modified adamantane alcohol B were mixed uniformly, subjected to twin-screw reaction extrusion (extruder temperature 120°C to 210°C, die head temperature 220°C), and then underwater pelletization to obtain thermoplastic polyurethane.

[0052] Example 8

[0053] 39.8wt% PBA (polybutylene adipate) with a molecular weight of 2000g / mol, 14.36wt% BDO (1,4-butanediol), 45.33wt% MDI (diphenylmethane diisocyanate), and 0.50wt% modified adamantane alcohol B were mixed uniformly, extruded by a twin-screw reaction (extruder temperature 80°C to 220°C, die head temperature 240°C), and then pelletized underwater to obtain thermoplastic polyurethane.

[0054] Comparative Example 1

[0055] 60wt% PBA (polybutylene adipate) with a molecular weight of 2000g / mol, 8.5wt% BDO (1,4-butanediol), and 31.5wt% MDI (diphenylmethane diisocyanate) were mixed evenly, extruded by a twin-screw reaction (extruder temperature 120°C to 210°C, die head temperature 220°C), and then pelletized underwater to obtain thermoplastic polyurethane.

[0056] Comparative Example 2

[0057] 60wt% NPG-PCL (neopentyl glycol initiated polycaprolactone diol) with a molecular weight of 2000g / mol, 8.1wt% BDO (1,4-butanediol), and 31.9wt% HMDI (4,4-dicyclohexylmethane diisocyanate) were mixed evenly, extruded by a twin-screw reaction (extruder temperature 120°C to 210°C, die head temperature 220°C), and then pelletized underwater to obtain thermoplastic polyurethane.

[0058] The performance data of the TPU provided in the above embodiments and comparative examples are shown in Table 1 below:

[0059] Table 1

[0060]

[0061]

[0062] As can be seen from the above table, the addition of modified adamantane alcohol can improve the transparency and demoulding properties of the material to a certain extent. The increase in the content of modified adamantane alcohol will reduce the haze of the material, facilitate demoulding and shorten the molding cycle. Based on the data of the embodiments and comparative examples, the 90A TPU material synthesized using PBA polyol has both transparency and demoulding advantages.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are within the spirit scope of the present invention.

Claims

1. A thermoplastic polyurethane, characterized in that: The raw materials comprising the following are prepared: 30-80 parts by weight of polyol; 0.01-10 parts by weight of modified adamantane alcohol; 20-50 parts by weight of diisocyanate; 3-17 parts by weight of diol chain extender; the modified adamantane alcohol has the following structural formula: wherein R1 and R2 are independently selected from a straight or branched chain alkyl group having 5 to 16 carbon atoms.

2. The thermoplastic polyurethane according to claim 1, characterized in that: The thermoplastic polyurethane is prepared from the following raw materials: 40-70 parts by weight of polyol; 0.1-5 parts by weight of modified adamantane alcohol; 24-46 parts by weight of diisocyanate; 5-15 parts by weight of diol chain extender.

3. The thermoplastic polyurethane according to claim 2, characterized in that: The thermoplastic polyurethane is prepared from the following raw materials: 50-65 parts by weight of polyol; 0.2-2 parts by weight of modified adamantane alcohol; 27-39 parts by weight of diisocyanate; 7-12 parts by weight of diol chain extender.

4. The thermoplastic polyurethane according to claim 1, characterized in that: In the structural formula of the modified adamantane alcohol, R1 and R2 are independently selected from straight-chain or branched alkyl groups having 8 to 10 carbon atoms.

5. The thermoplastic polyurethane according to claim 1, characterized in that: The polyol is a polyester polyol.

6. The thermoplastic polyurethane according to claim 1, characterized in that: The polyol is one of polyether polyol, polycaprolactone polyol and polycarbonate polyol or a combination thereof; the number average molecular weight of the polyol is 500-6000 g / mol.

7. The thermoplastic polyurethane according to claim 5 or 6, characterized in that: The number average molecular weight of the polyol is 1000-3000 g / mol.

8. The thermoplastic polyurethane according to claim 1, characterized in that: The diisocyanate is selected from one or more of aromatic diisocyanate, aliphatic diisocyanate and alicyclic diisocyanate.

9. The thermoplastic polyurethane according to claim 8, characterized in that: The diisocyanate is diphenylmethane diisocyanate.

10. The thermoplastic polyurethane according to claim 1, characterized in that: The diol chain extender is: aliphatic small molecule diol, the general formula is HO-C a H 2a -OH, a=a natural number from 1 to 10.

11. The thermoplastic polyurethane according to claim 10, characterized in that: In the general formula of the aliphatic small molecule diol, a=4.

12. The method for preparing a thermoplastic polyurethane according to any one of claims 1 to 11, characterized in that: The polyol, modified adamantane alcohol, diisocyanate and chain extender are uniformly mixed, and thermoplastic polyurethane is prepared by reaction extrusion.

13. The method for preparing thermoplastic polyurethane according to claim 12, characterized in that: The extrusion temperature of the reactive extrusion is 80-240°C.

14. The method for preparing thermoplastic polyurethane according to claim 13, characterized in that: The extrusion temperature of the reactive extrusion is 120-220°C.

15. Use of the thermoplastic polyurethane according to any one of claims 1 to 11 or the thermoplastic polyurethane prepared by the method according to any one of claims 12 to 14 for preparing injection molded parts or sheets.

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