MODIFIED COLLAGEN FIBER, AND PREPARATION METHOD AND APPLICATION

Abstract

A modified collagen fiber preparation method and application are provided. The modified collagen fiber is prepared by modifying a collagen fiber with a plant tannin; and a method of the preparation includes: mixing the plant tannin with the collagen fiber in a liquid environment with a pH of 5 to 8 to allow a reaction, and washing and drying a product. In the present disclosure, a plant tannin rich in phenolic hydroxyl can be combined with a collagen fiber in various ways such as multi-point hydrogen bonding and hydrophobic bonding, such that the plant tannin structure is introduced into a natural multi-layer micro/nano-structure of the collagen fiber; and due to a large number of phenolic hydroxyl structures in the plant tannin, the collagen fiber introduced with the plant tannin structure shows improved compatibility with a waterborne resin, and can produce strong hydrogen bonding with polar groups in the waterborne resin.

Claims

1. A modified waterborne resin composite material, wherein the modified waterborne resin composite material is prepared by a modified collagen fiber and a waterborne resin; wherein the waterborne resin comprises at least one selected from the group consisting of a waterborne polyurethane (WPU) resin, a waterborne polyester resin, a waterborne epoxy resin, and a waterborne acrylic resin; wherein a method for preparing the modified collagen fiber comprises the following steps: mixing a plant tannin with a collagen fiber in a liquid environment with a pH of 5 to 8 to allow a reaction, and washing and drying a product.

2. The modified waterborne resin composite material according to claim 1, wherein the plant tannin and the collagen fiber are mixed in the liquid environment with a pH of 6.5 to 7 to allow the reaction.

3. The modified waterborne resin composite material according to claim 1, wherein the plant tannin is a condensed tannin or a mixed tannin.

4. The modified waterborne resin composite material according to claim 1, wherein the plant tannin comprises at least one selected from the group consisting of bayberry tannin, black wattle tannin, larch tannin, Quebracho tannin, and Acacia mangium (A. mangium) tannin.

5. The modified waterborne resin composite material according to claim 4, wherein the plant tannin is bayberry tannin.

6. The modified waterborne resin composite material according to claim 1, wherein a mass ratio of the plant tannin to the collagen fiber is 1:(1-10).

7. The modified waterborne resin composite material according to claim 6, wherein the mass ratio of the plant tannin to the collagen fiber is 1:(2-5).

8. The modified waterborne resin composite material according to claim 6, wherein the mass ratio of the plant tannin to the collagen fiber is 1:(3-4).

9. The modified waterborne resin composite material according to claim 1, wherein the step of mixing the plant tannin with the collagen fiber in the liquid environment with the pH of 5 to 8 to allow the reaction comprises: mixing an aqueous solution of the plant tannin and an aqueous dispersion of the collagen fiber, and adjusting the pH to 5 to 8 with an alkali to allow the reaction.

10. The modified waterborne resin composite material according to claim 9, wherein the aqueous solution of the plant tannin is added to the aqueous dispersion of the collagen fiber for mixing.

11. The modified waterborne resin composite material according to claim 10, wherein the reaction is conducted for 1 hour to 10 hours.

12. The modified waterborne resin composite material according to claim 11, wherein the reaction is conducted for 2 hours to 8 hours.

13. The modified waterborne resin composite material according to claim 1, wherein the drying is conducted at 30° C. to 90° C. for 16 hours to 30 hours; and a method for the drying comprises one selected from the group consisting of natural air-curing, heat-drying, and vacuum-drying.

14. The modified waterborne resin composite material according to claim 13, wherein the drying is conducted at 60° C. to 85° C. for 18 hours to 26 hours.

15. The modified waterborne resin composite material according to claim 13, wherein the drying is conducted at 80±2° C. for 24±2 hours.

16. The modified waterborne resin composite material according to claim 1, wherein the collagen fiber is mainly prepared through pretreatment of leather shavings.

17. The modified waterborne resin composite material according to claim 16, wherein the leather shavings comprise metal-tanned leather shavings.

18. The modified waterborne resin composite material according to claim 16, wherein the leather shavings comprise blue leather shavings.

19. The modified waterborne resin composite material according to claim 16, wherein the pretreatment comprises: dewatering and crushing the leather shavings.

20. The modified waterborne resin composite material according to claim 19, wherein a method of the dewatering comprises at least one selected from the group consisting of natural air-curing, heat-drying, ethanol dewatering, lyophilization, and vacuum-drying.

21. The modified waterborne resin composite material according to claim 19, wherein a method of the dewatering comprises ethanol dewatering, lyophilization, and vacuum-drying.

22. The modified waterborne resin composite material according to claim 1, wherein the waterborne resin comprises at least one selected from the group consisting of the WPU resin, the waterborne polyester resin, and the waterborne acrylic resin.

23. The modified waterborne resin composite material according to claim 1, wherein the waterborne resin is the WPU resin.

24. The modified waterborne resin composite material according to claim 22, wherein a mass ratio of the modified collagen fiber to the waterborne resin is 1:(1-5).

25. The modified waterborne resin composite material according to claim 24, wherein the mass ratio of the modified collagen fiber to the waterborne resin is 1:(1.5-4).

26. The modified waterborne resin composite material according to claim 24, wherein the mass ratio of the modified collagen fiber to the waterborne resin is 1:(2-3).

27. A preparation method of the modified waterborne resin composite material according to claim 1, comprising the following steps: blending the modified collagen fiber and the waterborne resin, and molding a blended material.

28. The preparation method of the modified waterborne resin composite material according to claim 27, wherein the step of blending is conducted as follows: stirring a mixture of the modified collagen fiber and the waterborne resin for 30 min to 40 min at a stirring rate of 500 r/min to 3,000 r/min.

29. The preparation method of the modified waterborne resin composite material according to claim 27, wherein the step of molding is conducted as follows: placing the blended material in a mold, and drying at 90° C. to 120° C.

30. The preparation method of the modified waterborne resin composite material according to claim 27, wherein the step of molding is conducted by a hand laying-up technique.

31. The preparation method of the modified waterborne resin composite material according to claim 27, wherein the step of molding is conducted as follows: using a hand laying-up technique to coat the blended material on a surface of a base cloth or release paper with a roll coater, and drying at 90° C. to 120° C.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0058] Technical solutions of the present disclosure will be clearly and completely described below with reference to specific implementations. However, those skilled in the art will understand that the examples described below are merely some rather than all of the examples of the present disclosure, and the examples are only used to illustrate the present disclosure and should not be regarded as limiting the scope of the present disclosure. All other examples obtained by a person of ordinary skill in the art based on the examples of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure. If no specific conditions are specified in the examples, the examples will be conducted according to conventional conditions or the conditions recommended by the manufacturer. All of the used reagents or instruments which are not specified with manufacturers are conventional commercially-available products.

[0059] Some material information used in the specific examples of the present disclosure may be as follows:

[0060] blue leather shavings: which come from the waste of a tannery; and

[0061] WPU: which has a model of KT702E, and comes from Hefei Scisky Technology Co., Ltd. However, it is not limited to this.

[0062] The collagen fibers used in the following specific examples can be prepared from the blue leather shavings (but not limited to this), and a specific preparation method can be as follows:

[0063] the blue leather shavings are added to deionized water, a pH is adjusted to 6 with a 1 mol/L sodium bicarbonate aqueous solution, and the blue leather shavings are filtered out and dewatered with ethanol; and after ethanol volatilizes, the blue leather shavings are ground with an ultracentrifugal crusher equipped with a cooler or diffuser, and then sieved through a 40-mesh sieve to obtain the collagen fiber.

EXAMPLE 1

[0064] A preparation method of a modified collagen fiber was provided in this example, including the following steps:

[0065] (1) 1 kg of bayberry tannin was taken and added to 5 kg of deionized water, and a resulting mixture was stirred until the bayberry tannin was completely dissolved to obtain an aqueous solution of the bayberry tannin for later use.

[0066] 3 kg of a collagen fiber was taken and added to a container, then 150 kg of deionized water was added, and a resulting mixture was stirred such that the collagen fiber was uniformly dispersed in the deionized water to obtain an aqueous dispersion of the collagen fiber. A mass ratio of the tannin to the collagen fiber was 1:3.

[0067] (2) The aqueous solution of the bayberry tannin prepared in step (1) was added to the aqueous dispersion of the collagen fiber prepared in step (1) to obtain a mixed material; then a pH of the mixed material was adjusted to 6.5 to 7 and maintained stable using a 0.1 mol/L sodium bicarbonate aqueous solution, and the mixed material was mechanically stirred for 5 hours and then filtered through a Buchner funnel; a resulting solid material was washed 3 times with absolute ethanol to remove the unreacted bayberry tannin; and then the solid material was dried at 80±2° C. for 24 hours to obtain a bayberry tannin-modified collagen fiber (BT-LCF).

EXAMPLE 2

[0068] A preparation method of a modified collagen fiber was provided in this example, which was different from that in Example 1 in that:

[0069] a pH of the mixed material obtained in step (2) was adjusted to 5 and maintained stable using a 0.1 mol/L sodium bicarbonate aqueous solution.

EXAMPLE 3

[0070] A preparation method of a modified collagen fiber was provided in this example, which was different from that in Example 1 in that:

[0071] a pH of the mixed material obtained in step (2) was adjusted to 6 and maintained stable using a 0.1 mol/L sodium bicarbonate aqueous solution.

EXAMPLE 4

[0072] A preparation method of a modified collagen fiber was provided in this example, which was different from that in Example 1 in that:

[0073] a pH of the mixed material obtained in step (2) was adjusted to 8 and maintained stable using a 0.1 mol/L sodium bicarbonate aqueous solution.

EXAMPLE 5

[0074] A preparation method of a modified collagen fiber was provided in this example, which was different from that in Example 1 in that:

[0075] in step (1), 3 kg of bayberry tannin was taken and added to 15 kg of deionized water, and a resulting mixture was stirred until the bayberry tannin was completely dissolved to obtain an aqueous solution of the bayberry tannin for later use; and

[0076] 3 kg of a collagen fiber was taken and added to a container, then 150 kg of deionized water was added, and a resulting mixture was stirred such that the collagen fiber was uniformly dispersed in the deionized water to obtain an aqueous dispersion of the collagen fiber. A mass ratio of the bayberry tannin to the collagen fiber was 1:1.

EXAMPLE 6

[0077] A preparation method of a modified collagen fiber was provided in this example, which was different from that in Example 1 in that:

[0078] in step (1), 0.3 kg of bayberry tannin was taken and added to 1.5 kg of deionized water, and a resulting mixture was stirred until the bayberry tannin was completely dissolved to obtain an aqueous solution of the bayberry tannin for later use; and

[0079] 3 kg of a collagen fiber was taken and added to a container, then 150 kg of deionized water was added, and a resulting mixture was stirred such that the collagen fiber was uniformly dispersed in the deionized water to obtain an aqueous dispersion of the collagen fiber. A mass ratio of the bayberry tannin to the collagen fiber was 1:10.

EXAMPLE 7

[0080] A preparation method of a modified collagen fiber was provided in this example, which was different from that in Example 1 in that:

[0081] The black wattle tannin was used instead of the bayberry tannin at an equal amount.

EXAMPLES 8 TO 15

[0082] Different modified WPU composite materials and preparation methods thereof were provided in Examples 8 to 15. The compositions of the modified WPU composite materials are shown in Table 1 below.

TABLE-US-00001 TABLE 1 Compositions of different modified WPU composite materials Example No. Modified collagen fiber (BT-LCF) WPU Example 8 Example 1 WPU 3 kg KT702 E 6 kg Example 9 Example 2 WPU 3 kg KT702 E 6 kg Example 10 Example 3 WPU 3 kg KT702 E 6 kg Example 11 Example 4 WPU 3 kg KT702 E 6 kg Example 12 Example 5 WPU 3 kg KT702 E 6 kg Example 13 Example 6 WPU 3 kg KT702 E 6 kg Example 14 Example 7 WPU 3 kg KT702 E 6 kg Example 15 Example 1 WPU 3 kg KT702 E 9 kg Example 16 Example 1 WPU 3 kg KT702 E 12 kg 

[0083] The preparation methods of the modified WPU composite materials of Examples 8 to 16 included the following steps:

[0084] a modified collagen fiber and WPU were mixed according to the above ratio, and a resulting mixture was stirred for 30 min at room temperature and a stirring rate of 1,000 r/min, poured into a polytetrafluoroethylene (PTFE) mold, dried in an oven at 100±3° C., and taken out to obtain a modified WPU composite material (WPU/BT-LCF).

COMPARATIVE EXAMPLE 1

[0085] WPU KT702E was prepared with reference to the preparation methods of Examples 8 to 16, without the addition of a modified collagen fiber.

COMPARATIVE EXAMPLE 2

[0086] A material in Comparative Example 2 was prepared with reference to the preparation method of Example 15, except that an unmodified collagen fiber was used instead of the modified collagen fiber of Example 1 at an equal amount.

COMPARATIVE EXAMPLE 3

[0087] A material in Comparative Example 3 was prepared with reference to the preparation method of Example 1, except that a pH of the mixed material obtained in step (2) was adjusted to 4 and maintained stable using a 0.1 mol/L sodium bicarbonate aqueous solution.

COMPARATIVE EXAMPLE 4

[0088] A material in Comparative Example 4 was prepared with reference to the preparation method of Example 8, except that when the modified collagen fiber and the WPU were mixed according to the ratio in Example 8, 180 g of an aziridine cross-linking agent (3% of a mass of the WPU) was added.

EXPERIMENTAL EXAMPLE 1

[0089] In order to compare and illustrate the tensile strength of the modified WPU composite materials of the examples and comparative examples of the present disclosure, the tensile properties of the materials of Examples 8 to 16 and Comparative Examples 1 to 4 were tested with reference to the ASTM D412 standard, and test results are shown in Table 2.

TABLE-US-00002 TABLE 2 Tensile strength test results of different WPU materials Example No. Tensile strength/Mpa Example 8 8.34 Example 9 5.35 Example 10 6.87 Example 11 7.52 Example 12 5.17 Example 13 4.59 Example 14 7.91 Example 15 7.20 Example 16 6.95 Comparative Example 1 4.28 Comparative Example 2 5.01 Comparative Example 3 3.69 Comparative Example 4 2.56

EXPERIMENTAL EXAMPLE 2

[0090] In order to compare and illustrate the water vapor permeability of the modified WPU composite materials of the examples and comparative examples of the present disclosure, the water vapor permeability of the materials of Examples 8 to 16 and Comparative Examples 1 to 4 was tested with reference to the QBT1811-1993 standard, and test results are shown in Table 3.

TABLE-US-00003 TABLE 3 Water vapor permeability test results of different WPU materials Example No. Water vapor permeability (mg/(cm.sup.2 h)) Example 8 5457 Example 9 4580 Example 10 4729 Example 11 5025 Example 12 4490 Example 13 3313 Example 14 4956 Example 15 4682 Example 16 3502 Comparative Example 1 957 Comparative Example 2 3511 Comparative Example 3 2869 Comparative Example 4 2390

EXPERIMENTAL EXAMPLE 3

[0091] In order to compare and illustrate the aging resistance of the modified WPU composite materials of the examples and comparative examples of the present disclosure, the aging resistance of the materials of Examples 8 to 16 and Comparative Examples 1 to 4 was tested, and test results are shown in Table 4.

[0092] A specific test method is as follows: a material obtained in each of Examples 8 to 16 and Comparative Examples 1 to 4 was cut into dumbbell-shaped stripes, and the dumbbell-shaped stripes were divided into two groups; and one group was placed in a yellowing-resistance tester and irradiated for 72 hours under simulated fluorescent light, and the other group was used as a control sample and placed in a dark place without light for 72 hours. Parameters of the yellowing-resistance tester were set as follows: a power of a bulb: 300 W; a wavelength of a light source: 280 nm to 400 nm; an intensity of ultraviolet (UV) rays: 25±0.4 W/m.sup.2; a rotational speed of a sample tray: 3±1 r/min; a distance of a bottom edge of the bulb to the tray: 250±2 mm; and a temperature inside a box: 50±2° C. Then, the tensile strength and elongation at break were measured according to the ASTM D412 standard. Each sample was measured five times, and then an average value was taken.

TABLE-US-00004 TABLE 4 Aging resistance test results of different WPU materials Tensile strength Tensile strength before light after light Example No. exposure/Mpa exposure/Mpa Example 8 8.34 8.11 Example 9 5.35 4.75 Example 10 6.87 5.97 Example 11 7.52 7.24 Example 12 5.17 4.53 Example 13 4.59 4.16 Example 14 7.91 7.52 Example 15 7.20 6.89 Example 16 6.95 6.68 Comparative Example 1 4.28 3.01 Comparative Example 2 5.01 4.23 Comparative Example 3 3.69 1.65 Comparative Example 4 2.56 1.16

EXPERIMENTAL EXAMPLE 4

[0093] In order to compare and illustrate the flame resistance of the modified WPU composite materials of the examples and comparative examples of the present disclosure, the flame resistance of the materials of Examples 8 to 16 and Comparative Examples 1 to 4 was tested with reference to the ASTM D2863-77 standard, and test results are shown in Table 5.

TABLE-US-00005 TABLE 5 Flame resistance test results of different WPU materials Example No. LOI Example 8 24% Example 9 20% Example 10 21% Example 11 22% Example 12 20% Example 13 19% Example 14 23% Example 15 22% Example 16 21% Comparative Example 1 19% Comparative Example 2 20% Comparative Example 3 19% Comparative Example 4 18%

[0094] According to the above test results, compared with the composite material introduced with an unmodified collagen fiber, the tensile strength of the composite material of the present disclosure is increased by about 66.5%, the water vapor permeability is increased by about 55.4%, the aging resistance is significantly improved, and the change rate in tensile strength before and after light exposure is reduced by about 82.3%; compared with the composite material with the aziridine cross-linking agent, the tensile strength of the composite material of the present disclosure is increased by about 225.8%, the water vapor permeability is increased by about 128.3%, the aging resistance is significantly improved, and the change rate in tensile strength before and after light exposure is reduced by about 94.9%; compared with the composite material prepared from the modified collagen fiber with a pH of 4, the tensile strength of the composite material prepared from the modified collagen fiber with a pH adjusted to 6.5 to 7 is increased by about 126.1%, the water vapor permeability is increased by about 90.1%, the aging resistance is significantly improved, and the change rate in tensile strength before and after light exposure is reduced by about 95.0%. It indicates that, when the tannin, the collagen fiber, and the WPU have an appropriate mass ratio, the modified WPU composite material obtained by mixing the modified collagen fiber and the WPU according to the present disclosure shows significantly-improved mechanical properties, water vapor permeability, aging resistance, and flame resistance.

[0095] Finally, it should be noted that the above examples are merely intended to describe the technical solutions of the present disclosure, rather than to limit the present disclosure. Although the present disclosure is described in detail with reference to the above examples, persons of ordinary skill in the art should understand that modifications may be made to the technical solutions described in the above examples or equivalent replacements may be made to some or all technical features thereof, which do not make the essence of corresponding technical solutions depart from the scope of the technical solutions in the examples of the present disclosure.