Polyurethane composite material and preparation method and application thereof

Abstract

The application provides a polyurethane composite material and a preparation method and application thereof, and belongs to the technical field of high polymer composite materials.The application provides a polyurethane composite material, which comprises a soft polyurethane matrix and hard polyurethane fibers dispersed in the soft polyurethane matrix.Both the soft polyurethane matrix and the hard polyurethane fibers in the composite material are polyurethane, so that they have good compatibility, and the tensile strength and the elongation at break are improved.The results of examples show that the tensile strength of the polyurethane composite material can reach 30-60 MPa, and the elongation at break can reach 700-1600 %.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer composite material, in particular to a polyurethane composite material and a preparation method and application thereof. BACKGROUND

[0002] Thermoplastic polyurethane (TPU) is a kind of block copolymer composed of soft and hard segments, which has excellent elasticity, wear resistance, easy processability and structural versatility, and is widely used in damping materials, cushioning materials, communication and other fields. The unique molecular structure of TPU endows it with high mechanical properties and flexibility, and its mechanical properties have a significant impact on the practical application of TPU. Soft TPU has moderate tensile strength, but most TPU cannot meet the demand of high load strength and toughness in practical application.

[0003] In order to improve the strength and toughness of TPU, related literatures and patents improve the mechanical properties of TPU by polymer blending or nano-particle filling modification method, for example, melt blending nylon elastomer, thermoplastic polyester elastomer or polyolefin with TPU to improve the strength and toughness of TPU, and using nano-clay, carbon nanotube and cellulose nanocrystal as external reinforcing filler to improve the tensile strength of TPU. However, the second phase polymer or nano-particle and TPU form a heterogeneous polymer with poor compatibility, which cannot realize the super high reinforcement and toughening of TPU composite material. SUMMARY

[0004] The present application provides a polyurethane composite material and a preparation method and application thereof, and the compatibility of the soft polyurethane matrix and the hard polyurethane fiber in the polyurethane composite material of the present application is good, and the polyurethane composite material has excellent tensile strength and elongation at break.

[0005] The present application provides a polyurethane composite material, which comprises a soft polyurethane matrix and a hard polyurethane fiber dispersed in the soft polyurethane matrix.

[0006] Preferably, the mass ratio of the soft polyurethane matrix and the hard polyurethane fiber is 9-99:1.

[0007] Preferably, the soft polyurethane matrix and the hard polyurethane fiber are thermoplastic materials.

[0008] Preferably, the diameter of the hard polyurethane fiber is 80-150 μm.

[0009] Preferably, the preparation method of the hard polyurethane fiber comprises the following steps:

[0010] The hard polyurethane particles are melt-spun to obtain the hard polyurethane fiber.

[0011] Preferably, the number average molecular weight of the rigid polyurethane in the rigid polyurethane particles is 100-400 thousand.

[0012] The application further provides a preparation method of the polyurethane composite material, comprising the following steps:

[0013] The rigid polyurethane fibers are melt-blended with the soft polyurethane particles to obtain the polyurethane composite material.

[0014] The temperature of the melt-blending is higher than the melting temperature of the soft polyurethane particles but does not exceed the melting temperature of the rigid polyurethane fibers.

[0015] Preferably, the melting temperature of the rigid polyurethane fibers is 20-40℃ higher than the melting temperature of the soft polyurethane particles.

[0016] Preferably, after the melt-blending, the obtained blend is further annealed to induce the crystallization of the soft polyurethane, thereby obtaining the polyurethane composite material.

[0017] The application further provides an application of the polyurethane composite material or the polyurethane composite material prepared by the preparation method in the field of damping materials, cushioning materials or communication materials.

[0018] The application provides a polyurethane composite material, comprising a soft polyurethane matrix and rigid polyurethane fibers dispersed in the soft polyurethane matrix.

[0019] The soft polyurethane matrix and the rigid polyurethane fibers in the application are both polyurethane, thus they have good compatibility, and the tensile strength and elongation at break of the polyurethane composite material are improved. The results of the examples show that the tensile strength of the polyurethane composite material in the application can reach 30-60 MPa, and the elongation at break can reach 700-1600%.

[0020] Further, when the soft polyurethane matrix and the rigid polyurethane fibers are both thermoplastic materials, the used polyurethane composite material can be recycled.

[0021] Further, the annealing for inducing the crystallization of the soft polyurethane during the preparation of the polyurethane composite material can further improve the tensile strength and elongation at break of the polyurethane composite material. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 The cross-sectional electron microscope image of the self-reinforced TPU composite material obtained in Example 4;

[0023] Fig. 2 The cross-sectional electron microscope image of the soft TPU sample obtained in Comparative Example 1;

[0024] Fig. 3 Cross-section electron microscope image of the self-reinforced TPU composite material obtained in Comparative Example 3. DETAILED DESCRIPTION

[0025] The present application provides a polyurethane composite material, comprising a soft polyurethane matrix and hard polyurethane fibers dispersed in the soft polyurethane matrix.

[0026] In the present application, the mass ratio of the soft polyurethane matrix and the hard polyurethane fibers is preferably 9-99:1, more preferably 15-80:1, and further preferably 20-60:1.

[0027] In the present application, the preparation method of the hard polyurethane fibers preferably comprises the following steps:

[0028] The hard polyurethane particles are melt-spun to obtain the hard polyurethane fibers.

[0029] In the present application, before the melt spinning, the hard polyurethane particles are preferably dried.

[0030] The number average molecular weight of the hard polyurethane in the hard polyurethane particles is preferably 100-400 thousand, more preferably 150-300 thousand, and further preferably 200-250 thousand.

[0031] In the present application, the spinning temperature during the melt spinning is preferably 30-50℃ higher than the melting temperature of the hard polyurethane particles, and more preferably 40-45℃; the drawing temperature is preferably 50-80℃ lower than the melting temperature of the hard polyurethane particles, and more preferably 60-70℃; and the draw ratio is preferably 3.0-8.0, and more preferably 4-5.

[0032] In the present application, the diameter of the hard polyurethane fibers is preferably 80-150μm, and more preferably 100-120μm.

[0033] In the present application, the soft polyurethane matrix and the hard polyurethane fibers are preferably thermoplastic materials; the soft polyurethane in the soft polyurethane matrix and the hard polyurethane in the hard polyurethane fibers are preferably prepared from the same type of diisocyanate, chain extender and polyester / polyether polyol. The hard segment content of the hard polyurethane and the soft polyurethane is different.

[0034] In the present application, the polyurethane composite material does not use other chemical substances such as compatibilizers, coupling agents and second-phase polymers, which can ensure that the product is completely recyclable.

[0035] The present application also provides a preparation method of the polyurethane composite material described in the above technical solution, comprising the following steps:

[0036] The rigid polyurethane fiber is melt-blended with the soft polyurethane particle to obtain the polyurethane composite material.

[0037] The temperature of the melt-blending is higher than the melting temperature of the soft polyurethane particle but not higher than the melting temperature of the rigid polyurethane fiber.

[0038] Before the melt-blending, the present application preferably further comprises: drying the rigid polyurethane fiber and the soft polyurethane particle.

[0039] In the present application, the number average molecular weight of the polyurethane in the soft polyurethane particle is preferably 100-400 thousand, more preferably 150-300 thousand, and further preferably 200-250 thousand.

[0040] In the present application, the melting temperature of the rigid polyurethane fiber is preferably 20-40℃ higher than the melting temperature of the soft polyurethane particle, and more preferably 25-30℃.

[0041] The temperature of the melt-blending is preferably 20-40℃ higher than the melting temperature of the soft polyurethane particle, and more preferably 25-30℃.

[0042] In the present application, the time of the melt-blending is preferably 3-10 min, and more preferably 5-8 min; the melt-blending is preferably performed in a torque rheometer, and the screw rotation speed of the torque rheometer is preferably 40-70 rpm, and more preferably 50-60 rpm.

[0043] In the present application, after the melt-blending, the present application preferably further comprises: hot-pressing the blend obtained by the melt-blending.

[0044] In the present application, the temperature of the hot-pressing is preferably 20-40℃ higher than the melting temperature of the soft polyurethane particle, and more preferably 25-30℃, but not higher than the melting temperature of the rigid polyurethane fiber.

[0045] In the present application, the pressure of the hot-pressing is preferably 5-20 MPa, and more preferably 10-15 MPa.

[0046] In the present application, after the hot-pressing, the present application preferably further anneals the hot-pressed product to induce the crystallization of the soft polyurethane, to obtain the polyurethane composite material.

[0047] In the present application, the annealing is preferably performed in a CO2 environment; the temperature of the annealing is preferably 10-40℃ lower than the melting temperature of the soft polyurethane particle, and more preferably 20-30℃; the pressure is preferably 10-20 MPa, and more preferably 12-16 MPa; and the time is preferably 0.5-1.5 h, and further preferably 0.8-1.2 h.

[0048] The application further provides application of the polyurethane composite material in the damping material, the cushioning material or the communication material field.

[0049] The polyurethane composite material, the preparation method and the application thereof provided by the application are described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the application.

[0050] In the examples and the comparative examples: the hard TPU particles (TPU1160D) and the soft TPU particles (TPU1180A) are from BASF Shanghai Co., Ltd.

[0051] In the examples and the comparative examples, the tensile strength and the elongation at break are tested according to GB / T 1040-2006 (Determination of tensile properties of plastics) and the average value is obtained after testing at least 5 sample strips in each group.

[0052] Example 1

[0053] The hard TPU particles are vacuum dried at 100 ℃ for 12 h to remove water, and then melt spinning is performed to prepare the hard TPU continuous fibers, wherein the screw temperature is 210-225 ℃, the drawing temperature is 75 ℃, the drawing multiple is 8 times, and the diameter of the prepared fibers is 100 μm; the hard TPU continuous fibers and the soft TPU particles are vacuum dried at 100 ℃ and 70 ℃ respectively to remove water, the hard TPU continuous fibers and the soft TPU particles with a mass ratio of 1:99 are melt blended by a torque rheometer to prepare the hard TPU composite material, wherein the processing temperature is 175 ℃, the screw rotation speed is 50 rpm, and the processing time is 4 min; the hard TPU composite material is prepared by a hot press at 175 ℃ and 10 MPa, and the tensile strength and the elongation at break are tested, and the results are shown in Table 1.

[0054] Example 2

[0055] The hard TPU particles are vacuum dried at 100 ℃ for 12 h to remove water, and then melt spinning is performed to prepare the hard TPU continuous fibers, wherein the screw temperature is 210-225 ℃, the drawing temperature is 75 ℃, the drawing multiple is 8 times, and the diameter of the prepared fibers is 100 μm; the hard TPU continuous fibers and the soft TPU particles are vacuum dried at 100 ℃ and 70 ℃ respectively to remove water, the hard TPU continuous fibers and the soft TPU particles with a mass ratio of 3:97 are melt blended by a torque rheometer to prepare the hard TPU composite material, wherein the processing temperature is 175 ℃, the screw rotation speed is 50 rpm, and the processing time is 4 min; the hard TPU composite material is prepared by a hot press at 175 ℃ and 10 MPa, and the tensile strength and the elongation at break are tested, and the results are shown in Table 1.

[0056] Example 3

[0057] The rigid TPU particles were vacuum dried at 100°C for 12h to remove moisture, and melt spinning was performed to prepare rigid TPU continuous fibers, with screw temperature of 210-225°C, drawing temperature of 75°C, drawing multiple of 8, and fiber diameter of 100μm. The rigid TPU continuous fibers and the soft TPU particles were vacuum dried at 100°C and 70°C respectively to remove moisture, and rigid TPU composite was prepared by melt blending of the rigid TPU continuous fibers and the soft TPU particles with mass ratio of 5:95 through a torque rheometer, with processing temperature of 175°C, screw rotation speed of 50rpm, and processing time of 4min. The rigid TPU composite was prepared by hot pressing at 175°C and 10MPa through a hot press, and tensile strength and elongation at break were tested, with results shown in Table 1.

[0058] Example 4

[0059] The rigid TPU particles were vacuum dried at 100°C for 12h to remove moisture, and melt spinning was performed to prepare rigid TPU continuous fibers, with screw temperature of 210-225°C, drawing temperature of 75°C, drawing multiple of 8, and fiber diameter of 100μm. The rigid TPU continuous fibers and the soft TPU particles were vacuum dried at 100°C and 70°C respectively to remove moisture, and rigid TPU composite was prepared by melt blending of the rigid TPU continuous fibers and the soft TPU particles with mass ratio of 7:93 through a torque rheometer, with processing temperature of 175°C, screw rotation speed of 50rpm, and processing time of 4min. The rigid TPU composite was prepared by hot pressing at 175°C and 10MPa through a hot press, and tensile strength and elongation at break were tested, with results shown in Table 1.

[0060] Example 5

[0061] The rigid TPU particles were vacuum dried at 100°C for 12h to remove moisture, and melt spinning was performed to prepare rigid TPU continuous fibers, with screw temperature of 210-225°C, drawing temperature of 75°C, drawing multiple of 8, and fiber diameter of 100μm. The rigid TPU continuous fibers and the soft TPU particles were vacuum dried at 100°C and 70°C respectively to remove moisture, and rigid TPU composite was prepared by melt blending of the rigid TPU continuous fibers and the soft TPU particles with mass ratio of 10:90 through a torque rheometer, with processing temperature of 175°C, screw rotation speed of 50rpm, and processing time of 4min. The rigid TPU composite was prepared by hot pressing at 175°C and 10MPa through a hot press, and tensile strength and elongation at break were tested, with results shown in Table 1.

[0062] Example 6

[0063] The rigid TPU particles were vacuum dried at 100°C for 12h to remove moisture, and melt spinning was performed to prepare rigid TPU continuous fibers, with screw temperature of 210-225°C during spinning, drawing temperature of 75°C, drawing multiple of 8, and fiber diameter of 100μm; the rigid TPU continuous fibers and the soft TPU particles were vacuum dried at 100°C and 70°C respectively to remove moisture, and rigid TPU composite was prepared by melt blending of the rigid TPU continuous fibers and the soft TPU particles with mass ratio of 7:93 through torque rheometer, with processing temperature of 175°C, screw rotation speed of 50rpm, and processing time of 4min; the rigid TPU composite was prepared by hot pressing at 175°C and 10MPa through a hot press; the rigid TPU composite sample was annealed at 130°C and 15MPa CO2 for 1h to obtain annealed rigid TPU composite, and tensile strength and elongation at break were tested, with results shown in Table 1.

[0064] Comparative Example 1

[0065] The soft TPU particles were vacuum dried at 70°C to remove moisture, and TPU sample was prepared by melt through torque rheometer, with processing temperature of 175°C, screw rotation speed of 50rpm, and processing time of 4min; the soft TPU sample was prepared by hot pressing at 175°C and 10MPa through a hot press, and tensile strength and elongation at break were tested, with results shown in Table 1.

[0066] Comparative Example 2

[0067] The rigid TPU particles were vacuum dried at 100°C to remove moisture, and rigid TPU sample was prepared by melt through torque rheometer, with processing temperature of 210°C, screw rotation speed of 50rpm, and processing time of 4min; the rigid TPU sample was prepared by hot pressing at 210°C and 10MPa through a hot press, and tensile strength and elongation at break were tested, with results shown in Table 1.

[0068] Comparative Example 3

[0069] The rigid TPU particles and the soft TPU particles were vacuum dried at 100°C and 70°C respectively to remove moisture, and rigid TPU composite was prepared by melt blending of the rigid TPU particles and the soft TPU particles with mass ratio of 7:93 through torque rheometer, with processing temperature of 175°C, screw rotation speed of 50rpm, and processing time of 4min; the rigid TPU composite was prepared by hot pressing at 175°C and 10MPa through a hot press, and tensile strength and elongation at break were tested, with results shown in Table 1.

[0070] Table 1 Tensile strength and elongation at break of materials obtained in Examples 1-6 and Comparative Examples 1-3

[0071]

[0072]

[0073] Fig. 1 This is a cross-sectional electron microscope image of the self-reinforced TPU composite material obtained in Example 4; Fig. 2 The image shows a cross-sectional electron microscope image of the soft TPU spline obtained in Comparative Example 1. Fig. 3 The image shows a cross-sectional electron microscope image of the self-reinforced TPU composite material obtained in Comparative Example 3.

[0074] Depend on Figs. 1-3 It can be seen that, compared with the self-reinforced TPU composite material formed by rigid TPU particles and soft TPU, rigid TPU fibers can be uniformly distributed in the soft TPU matrix, and the two have good compatibility, which is beneficial to improving the strength and toughness of the self-reinforced TPU composite material.

[0075] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A polyurethane composite, characterized in that, The polyurethane composite comprises a soft polyurethane matrix and hard polyurethane fibers dispersed in the soft polyurethane matrix. The polyurethane composite is prepared by the following steps: The hard polyurethane fibers are melt-blended with the soft polyurethane particles, the obtained blend is hot-pressed, and then the obtained hot-pressed product is annealed to induce crystallization of the soft polyurethane, thereby obtaining the polyurethane composite; the annealing is performed in a CO2 environment. The temperature of the melt-blending is above the melting temperature of the soft polyurethane particles but not higher than the melting temperature of the hard polyurethane fibers.

2. The polyurethane composite according to claim 1, characterized in that, The mass ratio of the soft polyurethane matrix to the hard polyurethane fibers is 9-99:

1.

3. The polyurethane composite according to claim 1 or 2, characterized in that, The soft polyurethane matrix and the hard polyurethane fibers are thermoplastic materials.

4. The polyurethane composite according to claim 1 or 2, characterized in that, The diameter of the hard polyurethane fibers is 80-150 μm.

5. The polyurethane composite of claim 1, wherein, The hard polyurethane fibers are prepared by the following steps: The hard polyurethane fibers are obtained by melt-spinning the hard polyurethane particles.

6. The polyurethane composite of claim 5, wherein, The number average molecular weight of the hard polyurethane in the hard polyurethane particles is 100-400 thousand.

7. Process for the production of the polyurethane composite material according to any one of claims 1 to 6, characterized in that, The hard polyurethane fibers are melt-blended with the soft polyurethane particles, the obtained blend is hot-pressed, and then the obtained hot-pressed product is annealed to induce crystallization of the soft polyurethane, thereby obtaining the polyurethane composite; the annealing is performed in a CO2 environment. The temperature of the melt-blending is above the melting temperature of the soft polyurethane particles but not higher than the melting temperature of the hard polyurethane fibers. The melting temperature of the hard polyurethane fibers is 20-40℃ higher than the melting temperature of the soft polyurethane particles.

8. The preparation method according to claim 7, characterized in that, 9. Use of the polyurethane composite of any one of claims 1-6 or the polyurethane composite prepared by the method of any one of claims 7-8 in the field of damping materials, cushioning materials or communication materials. ​

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