CN114085446A

CN114085446A - Creep-resistant composite material and preparation method thereof

Info

Publication number: CN114085446A
Application number: CN202111494567.5A
Authority: CN
Inventors: 许维星; 雷超; 曾运航; 石碧
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2021-12-08
Filing date: 2021-12-08
Publication date: 2022-02-25

Abstract

The invention belongs to the technical field of composite materials, and discloses a creep-resistant composite material and a preparation method thereof. The creep-resistant composite material comprises thermoplastic high polymer and modified collagen fiber which are mixed according to the weight ratio of 100 (1-100). The creep-resistant composite material can be obtained by blending and molding the modified collagen fiber and the high polymer, and the creep resistance of the high polymer can be improved without reducing or even increasing the resilience of the high polymer. The collagen fiber adopted by the invention is renewable natural fiber, has wide source and low price, and compared with the existing modification method, the method for preparing the creep-resistant composite material by using the collagen fiber has lower cost.

Description

Creep-resistant composite material and preparation method thereof

Technical Field

The invention relates to the technical field of composite materials, in particular to a collagen fiber modified creep-resistant composite material and a preparation method thereof.

Background

The high polymer material has a macromolecular chain structure and characteristic thermal motion, which determines that the high polymer material has different physical properties from the low molecular material. The mechanical property of the high polymer material is characterized in that the high polymer material has high elasticity and viscoelasticity. The viscoelasticity of high polymers can be divided into static viscoelasticity and dynamic viscoelasticity. Among these, creep is one of the properties reflecting static viscoelasticity. Creep refers to the phenomenon in which the degree of deformation of a material increases with time under a force. Creep is reflected by the rheological properties of a material under load, i.e. the flow after loading; the intrinsic viscoelasticity of plastics and other high molecular materials is reflected. Creep resistance is the ability of a material to resist this deformation process. The resilience refers to the ability of an object to quickly recover its original shape after the external force causing the deformation of the object is removed.

In the prior art, the following methods are generally adopted to improve the creep resistance and rebound resilience of high polymers: (1) changing synthetic monomers from a molecular angle to perform multi-component copolymerization, such as ABS (terpolymer of acrylonitrile (A), butadiene (B) and styrene (S)) plastic; functional Polyurethane (PU); modifying the latex. However, this method must be based on the raw material composition layer and is not suitable for conventional materials. (2) Adding a component with creep resistance or rebound resilience into a high polymer, such as a stone-plastic polyvinyl chloride (PVC) plate, and using the hardness of stone powder to make the material not easy to deform, but the same stone-plastic plate has much lower rebound resilience than a pure PVC plate; for another example, foamed PVC increases the resilience of the material, but the creep resistance is not so strong, and the material obtained by the method cannot improve the creep resistance and the resilience of the material at the same time.

Disclosure of Invention

To solve the problems of the background art, a first object of the present invention is to provide a creep-resistant composite material whose creep resistance is significantly improved without a decrease in resilience.

The second purpose of the invention is to provide a preparation method of the creep-resistant composite material, and the creep resistance and resilience of the composite material prepared by the method can be synchronously improved.

In order to achieve the above object, the first technical solution adopted by the present invention is:

the creep-resistant composite material comprises a thermoplastic polymer and modified collagen fibers which are mixed according to the weight ratio of 100 (1-100);

preferably, the modified collagen fiber comprises 100 (5-50) parts by weight of thermoplastic high polymer and modified collagen fiber.

Preferably, the thermoplastic polymer is a polymer material which can be processed by melt thermoplastic processing and has a processing temperature not higher than the dry heat denaturation temperature of the collagen fibers, and the thermoplastic polymer can reduce the processing temperature to below the dry heat deformation temperature of the collagen fibers by plasticizing and the like.

More preferably, the thermoplastic polymer includes, but is not limited to, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyacetal, polyether, acrylate polymer, thermoplastic polyester, thermoplastic polyurethane, hexamethylolmelamine.

Preferably, the modified collagen fibers are obtained by crushing or mechanochemical activation treatment of pretreated collagen fibers to 2-2500 meshes;

more preferably, the pulverization or mechanochemical activation treatment is 32 to 300 mesh.

Preferably, the pretreated collagen fibers are washed and dried collagen fibers;

the raw material of the collagen fiber is selected from any one or more of leather scraps and tanning.

The second technical scheme adopted by the invention is as follows:

a method for preparing a creep-resistant composite material comprises the step of blending and forming modified collagen fibers and a thermoplastic high polymer.

Preferably, the modification treatment comprises: crushing or performing mechanochemical activation treatment on the pretreated collagen fibers to 2-2500 meshes, and preferably to 32-300 meshes;

preferably, the pretreatment comprises washing collagen fibers with water and drying.

Preferably, the modification treatment further comprises a micro-modification treatment and/or a coupling agent modification treatment after the pulverization or mechanochemical activation treatment.

Preferably, the micro-modification treatment is to place the collagen fibers in an air or solvent environment and heat the collagen fibers at 20-240 ℃ for 5 minutes-30 days;

more preferably, the heating is carried out for 15 to 90 minutes at the temperature of 75 to 160 ℃;

preferably, the heating is microwave heating or direct heating.

Preferably, the coupling agent used for modifying the coupling agent comprises any one or more of silanes, titanates, aluminates, organochromium complexes, borides, phosphates, zirconates, stannates and epoxidized soybean oil.

Preferably, the dosage of the coupling agent is 0.5-20% of the dosage of the collagen fiber, and preferably 3-10%.

Compared with the prior art, the invention has the beneficial effects that:

the creep resistance of the composite material obtained by blending the modified collagen fiber and the thermoplastic polymer is obviously better than that of the thermoplastic polymer, and meanwhile, the rebound resilience of the thermoplastic polymer can not be reduced or even increased.

The collagen fiber adopted by the invention is used as a renewable natural fiber, has wide source and low price, and has lower cost compared with the existing modification method.

The composite material obtained by the invention is not easy to deform and has better durability on the premise of basically keeping the performance of the original high polymer.

Drawings

FIG. 1 is a graph showing creep and recovery curves of the materials of examples 5 to 6 and comparative examples 5 to 8.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The invention provides a creep-resistant composite material, which comprises thermoplastic high polymer and modified collagen fiber mixed according to the weight ratio of 100 (1-100); preferably, the modified collagen fiber comprises 100 (5-50) parts by weight of thermoplastic high polymer and modified collagen fiber.

The collagen fiber is a natural macromolecule, has good size stability, and is not easy to creep. Therefore, the composite material can play a better role in fixing and supporting after being compounded with the thermoplastic high polymer base material, thereby improving the overall creep resistance of the composite material. The special multi-level structure of the composite material has the effect similar to a pore structure in a porous wood-plastic plate, and the creep resistance and the resilience of the composite material are synchronously improved. And the modification effect of the collagen fiber on the high polymer substrate can be further strengthened by adopting a proper interface modification method.

Just as with natural leather, the resilience of collagen fibers is also incomparable with other synthetic materials. After being blended with a thermoplastic high polymer substrate, the rebound property of the thermoplastic high polymer substrate can assist the rebound of the high polymer substrate. In addition, because the collagen fibers are a material with flexibility and toughness, when the material is stressed and deformed, the collagen fibers can deform and orient along with stress. These deformations, orientations, are recovered by the effect of the resilient return of the toughness after the stress is removed, so that the material exhibits better resilience.

In some embodiments, the raw material of the collagen fibers is selected from any one or more of a leather crumb and a tanned leather. Wherein, the leather scraps refer to leather making leftover wastes generated by operations such as chipping, buffing, cutting and the like in the leather making process; tanning refers to the semi-finished product in the leather production process. The tanned leather is selected from any one or more of chrome tanned leather, aldehyde tanned leather, vegetable tanned leather, non-chrome metal tanned leather, organic tanned leather, combined tanned leather and the like.

The thermoplastic polymer of the present invention is a polymer material that can be processed by melt thermoplastic processing at a temperature not higher than the dry heat denaturation temperature of collagen fibers. The high polymer of the present invention can be used for preparing a high polymer, wherein part of the high polymer has a self-processing temperature higher than the dry heat denaturation temperature of the collagen fibers, and the processing temperature of the high polymer can be reduced to be below the dry heat denaturation temperature of the collagen fibers by using a proper plasticizing method.

In some preferred embodiments, the thermoplastic polymer includes, but is not limited to, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyacetal, polyether, acrylate polymer, thermoplastic polyester, thermoplastic polyurethane, hexamethylolmelamine, and the like.

The modification treatment of the collagen fiber can be selected from pulverization or mechanochemical activation treatment. Wherein the pulverization is ordinary pulverization; mechanochemical activation is a technical means for increasing the defibration rate and activating fibers. The mesh number of the collagen fiber pulverization or mechanochemical activation treatment is determined according to the structure of the treated collagen fiber. The purpose of crushing is to break the collagen fibers; mechanochemical activation, apart from being interrupted, can also break up; the collagen fiber powder is guaranteed to have a multi-branch structure, so that the material is supported better, and the material creep is prevented. If the activation is excessive, the multi-branched structure is completely cut off, resulting in loss of the modifying effect of the material. The degree of activation was comprehensively evaluated by mesh number, defibration rate and water absorption. The higher the activation degree, the smaller the mesh number and the higher the defibration rate; the water absorption rate is changed by increasing and then decreasing, and the water absorption is properly activated to be enhanced; excessive activation, mechanical forces and concomitant heating phenomena can lead to the removal of hydrophilic groups (amino, carboxyl, hydroxyl, etc.) on the collagen molecules, which in turn reduces water absorption. For ordinary crushing, the defibration rate of collagen fibers is about 30%, and after air conditioning is carried out for 48 hours in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50%), the water absorption rate is 8-20%; the defibration rate of the activated collagen fibers is greater than 50%, and the water absorption rate is 12% -50% after air conditioning is carried out for 48 hours in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50%). The overlapping of the variation ranges of the water absorption rates of the ordinary crushed and mechanochemical activated collagen fibers is caused by different types of the collagen fibers, and the water absorption rate of the same type of collagen fibers after mechanochemical activation is higher than that of the collagen fibers obtained by the ordinary crushing method.

The pretreatment of the collagen fibers includes washing the collagen fibers with water and drying the collagen fibers. When the collagen fiber raw material is derived from leather scraps, the collagen fiber raw material can be directly washed with water and dried, and then the subsequent treatment step is carried out; when the collagen fiber raw material is used for tanning, the raw material is firstly coarsely crushed and then washed by water and dried. Wherein the coarse grinding is to grind the tanned leather to a particle size of less than 2 cm by using conventional grinding equipment such as a crusher, a cutting machine, a grinder, a leather grinder and the like. The water washing is to wash the collagen fiber raw material with an aqueous solution containing a surfactant, and remove impurities such as oil and fat, inorganic salts and the like in the raw material by a water washing mode. The surfactant can be any common surfactant product on the market. Drying is carried out by conventional drying means.

The second embodiment of the invention provides a preparation method of the creep-resistant composite material, which comprises the step of blending and forming the modified collagen fibers and the thermoplastic high polymer.

In some embodiments, the high polymer is mixed with the modified collagen fiber by using one of conventional mixing devices such as a screw mixer, a ribbon mixer, a three-dimensional motion mixer, a blender, an open mill, an internal mixer, a twin-screw extruder, and the like; the polymer and the modified collagen fiber, which are uniformly mixed, are subjected to material molding using any one of conventional molding apparatuses such as an extruder, an injection machine, a press vulcanizer, and a calender. The mixing and forming process of the high polymer substrate and the collagen fiber can refer to the forming process of the conventional high polymer substrate, and the specific process parameters such as equipment, temperature and the like depend on the type of the high polymer substrate. In the blending process, a foaming agent, a plasticizer and the like can be added if necessary to enhance the modification effect.

The modification treatment comprises: and crushing or performing mechanochemical activation treatment on the pretreated collagen fibers to 2-2500 meshes, preferably 32-300 meshes.

In order to further improve the performance of the collagen fiber and enhance the modification effect, the collagen fiber can also comprise micro-modification treatment and/or coupling agent modification treatment after pulverization or mechanochemical activation treatment. The micro-modification treatment is to modify collagen fibers by microwave heating or direct heating in air or solvent environment, so that the phase structure is changed, the flexibility is increased, the resilience is improved, the creep resistance is poor, and an ultrasonic treatment means is added if necessary.

When the micro-denaturing treatment and the coupling agent modification are simultaneously required, the micro-denaturing treatment must be performed prior to the coupling agent modification. In addition, after the micro-modification treatment and the modification of the coupling agent, due to the capillary action in the solvent removal process, the collagen fibers can be partially bonded, which is not beneficial to the modification of the high polymer. Therefore, the operations of washing, drying and pulverizing are performed again to re-uniformly disperse the bonded collagen fibers.

In some preferred embodiments, the heating is at 20 to 240 ℃ for 5 minutes to 30 days; more preferably, the heating is carried out at 75-160 ℃ for 15-90 minutes. The heating is microwave heating or direct heating.

Preferably, the collagen fibers can be further activated by using ultrasonic assistance in the heating process, the ultrasonic frequency is 20-200 kHz, and the ultrasonic power is 10-1500W; preferably, the ultrasonic frequency is 60-100 kHz, and the ultrasonic power is 100-400W.

In some preferred embodiments, the solvent comprises any one or more of water, ethanol, acetone, dodecane, glycerol, petroleum ether, and dimethicone.

The coupling agent used for modifying the coupling agent comprises any one or more of silanes, titanates, aluminates, organic chromium complexes, borides, phosphates, zirconates, stannates and epoxidized soybean oil. The dosage of the coupling agent is 0.5-20% of the dosage of the collagen fiber, and preferably 3-10%. The coupling agent application process (temperature, pH, solvent, time) and the like are determined according to the type of the coupling agent selected, and the process conditions refer to the conventional application process.

In order to better understand the technical solution provided by the present invention, the following description will respectively illustrate the preparation method and performance test of the collagen fiber modified creep-resistant composite material provided by the above embodiments of the present invention with a plurality of specific examples.

Some of the material information used in the embodiments of the present invention may be as follows:

non-chrome metal tanned leather is from Hebei Xinji Dongming leather Co., Ltd;

chrome tanned leather and leather scraps come from Haining Rexingxin leather Co., Ltd, and the leather scraps are leather making corner wastes generated by chipping, grinding and cutting operations in the leather making process of the chrome tanned leather;

aminopropyltriethoxysilane (KH 550), technical grade, manufactured by Dinghai plastics chemical Co., Ltd, Dongguan;

tetrabutylammonium bromide, technical grade, manufactured by chemical limited of the creation of the country of Jinan;

polyvinyl chloride (PVC) manufactured by Xinjiang Zhongtai chemical Co., Ltd, and having a model of PVC-SG 5;

polyethylene (PE) of model DMDA-8008, manufactured by Leisha petrochemicals, Inc., of Sinkiang;

polystyrene (PS), manufactured by Zhenjiangqi beautifier ltd, model PG-33;

thermoplastic styrene butadiene rubber (SBS) manufactured by Zhongpetrochemical Balng petrochemical Co., Ltd., model YH-792(SBS 1401);

hexamethylol Melamine (HM), technical grade, manufactured by chongqing kurtosis chemical company limited;

dioctyl phthalate (DOP) plasticizer, the manufacturer is Jiangsu Chuangteng New Material science and technology limited company, the model is 117-81-7;

the mineral white oil plasticizer is manufactured by Shenzhen Mizhongtonghu chemical Co., Ltd, and has the model number of 68 #;

azodicarbonamide (AC) foaming agent, the manufacturer is Jiheng New Material Co., Ltd, of Foshan city, model number is AG-250;

the wood powder is produced by Hebei Jinghang mineral products, Inc., the model is wood-plastic poplar wood powder 2018-80, and the fineness is 100 meshes;

the stone powder is a stone-plastic marble-imitated calcium powder manufactured by Zhejiang Sungfeng calcium industry Co., Ltd, and has a whiteness of 95 and a fineness of 1250 meshes.

Example 1

(1) Pretreatment of collagen fibers: the method comprises the steps of mechanically stirring and mixing 100 parts of leather scraps, 400 parts of water and 2 parts of white cat lemon black tea detergent for 2 hours at 25 ℃, filtering water, mechanically stirring and mixing 400 parts of water for 2 hours at 25 ℃, filtering water, fully drying. In the step, water is filtered after being mixed with water and/or a surfactant for many times, so that the leather scraps are cleaned, and the use amounts of the water and the surfactant are not limited to the above, and can be adjusted according to actual conditions.

(2) And (2) crushing the pretreated collagen fibers in the step (1), crushing by using a traditional rotary cutter type crusher at the rotating speed of 2400 rpm for 8 minutes, wherein the mesh number of the crushed collagen fibers is about 18 meshes, the defibration rate is about 28.60%, and the equilibrium water absorption rate is 8.41% after air conditioning in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50%) for 48 hours.

(3) And (3) extruding and molding 10 parts of the collagen fiber in the step (2) and 100 parts of PE in a double-screw extruder to obtain the PE composite material modified by the collagen fiber.

Example 2

(1) Pretreatment of collagen fibers: non-chrome metal tanned leather is taken as a collagen fiber raw material, and is washed and dried by water after being coarsely crushed according to the pretreatment method in the example 1.

(2) The pretreated collagen fibers in the step (1) are crushed, a millstone type mechanochemical reactor is used, the rotating speed is 60 rpm, the crushing times are 16 times, the mesh number of the activated collagen fibers is about 200, the defibration rate is about 53.24 percent, and after the collagen fibers are subjected to air conditioning in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50 percent) for 48 hours, the equilibrium water absorption rate is 49.41 percent.

(3) Soaking the collagen fibers in the step (2) in water at 75 ℃ for 60 minutes, and draining.

(4) Dissolving 15 parts of KH550 in 1500 parts of isopropanol-water (9: 1) mixed solvent, then putting 100 parts of the collagen fibers in the solution (3), stirring for 6 hours at room temperature, and adjusting the pH value with 0.1 mol/formic acid during stirring to stabilize the pH value of the suspension to 6.0-7.0; then the pH value is adjusted to 4.0, and the mixture is continuously stirred for 2 hours at normal temperature and then filtered out.

(5) And (3) placing the filtrate obtained in the step (4) in a 120 ℃ oven for heating reaction for 18 hours, washing by using 95% ethanol to remove unbound KH550, drying again, and crushing by using a traditional rotary cutter type crusher at the rotation speed of 1200 rpm for 2 minutes.

(6) And (3) banburying 100 parts of PS and 5 parts of white oil at 200 ℃ for 15 minutes, then cooling to 150 ℃, adding 30 parts of the collagen fiber obtained in the step (5), continuously banburying for 30 minutes, and then performing injection molding to obtain the collagen fiber modified PS composite material.

Example 3

(1) Pretreatment of collagen fibers: the chrome tanned leather is taken as a collagen fiber raw material, is roughly crushed and then is washed and dried by water according to the pretreatment method in the example 1.

(2) The pretreated collagen fibers in the step (1) are crushed, a centrifugal force chemical reactor is used, the rotating speed is 12000 rpm, the aperture of a net knife is 0.25 mm, the rotary knife is a 16-tooth parallel rotary knife, the mesh number of the activated collagen fibers is about 270 meshes, the defibration rate is about 69.65%, and after the air conditioning is carried out in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50%) for 48 hours, the equilibrium water absorption rate is 23.56%.

(3) 100 parts of methacrylic acid were adjusted to pH-1 using NaOH, and 400 parts of a basic chromium sulfate solution (50% strength) having been adjusted to pH 1.0 were then slowly added. Then MgO is used for adjusting the pH value to 3.5, and 0.5 part of hydroquinone is added and mixed evenly to obtain the chromium sulfate methacrylate solution.

(4) Soaking 100 parts of the collagen fiber obtained in (2) in 500 parts of 25 ℃ water, adding 15 parts of the chromium methacrylate sulfate solution obtained in (3), stirring for 2 hours, adjusting the time to 4.0 hours by using a 10% sodium bicarbonate solution, continuing stirring for 1.5 hours, and filtering.

(5) And (3) sealing the filtrate obtained in the step (4), placing the filtrate in a 40 ℃ oven, heating for reaction for 48 hours, washing with water to remove unbound chromium methacrylate chloride, drying again, and crushing with a traditional rotary cutter type crusher at the rotation speed of 800 rpm for 1 minute.

(6) And (3) mixing 100 parts of SBS, 5 parts of AC, 3 parts of sulfur and 50 parts of the collagen fiber obtained in the step (5) at 140 ℃ for 10 minutes, vulcanizing and foaming on a flat vulcanizing machine for 30 minutes at the vulcanization temperature of 180 ℃, and finishing vulcanization to obtain the collagen fiber modified foamed SBS composite material.

Example 4

(2) And (2) crushing the pretreated collagen fibers in the step (1), using a multi-roller meshing type mechanochemical reactor, rotating at 30 rpm for 5 times, wherein the mesh number of the activated collagen fibers is about 180 meshes, the defibration rate is about 54.33%, and after air conditioning in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50%) for 48 hours, the equilibrium water absorption rate is 21.48%.

(3) Soaking the collagen fibers in the step (2) in glycerol, heating to 120 ℃ by using microwaves for 20 minutes, draining the solvent, repeatedly washing by using water to remove residual glycerol, drying, and crushing by using a traditional rotary cutter type crusher again at the rotation speed of 1000 rpm for 3 minutes.

(4) And (3) uniformly mixing 100 parts of hour M and 5 parts of the collagen fiber obtained in the step (3) in a three-dimensional mixer, and hot-pressing for 15 minutes by using a hot press at 180 ℃ and 15MPa to obtain the collagen fiber modified Melamine Formaldehyde (MF) resin composite material.

Example 5

(1) Pretreatment of collagen fibers: the leather scraps were used as a raw material of collagen fibers, and were washed with water and dried by the pretreatment method described in reference example 1.

(2) Crushing the pretreated collagen fibers in the step (1), using a cutting type mechanochemical reactor, rotating at 6000 rpm, and sieving with a screen mesh diameter of 0.12mm, wherein the mesh number of the activated collagen fibers is about 140 meshes, the defibration rate is about 71.19%, and after air conditioning in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50%) for 48 hours, the equilibrium water absorption rate is 24.40%.

(3) Soaking the collagen fibers in the step (2) in ethanol-acetone (1: 1) mixed solvent at 55 ℃ for 45 minutes, performing ultrasonic treatment at 100kHz and 300W simultaneously during soaking, and draining the solvent after soaking.

(4) 50 parts of epoxidized soybean oil and 5 parts of tetrabutylammonium bromide were dissolved in 800 parts of isopropanol, then 100 parts of (3) was added to obtain collagen fibers, and the solvent was filtered off after stirring at 80 ℃ for 8 hours.

(5) And (3) continuously reacting the collagen fibers obtained in the step (4) in a 90 ℃ oven for 10 hours, cleaning the collagen fibers by using isopropanol to remove unreacted epoxidized soybean oil, drying the collagen fibers again, and crushing the collagen fibers by using a traditional rotary cutter type crusher at the rotating speed of 1600 rpm for 6 minutes.

(6) And (3) banburying 100 parts of PVC, 20 parts of DOP and 25 parts of the collagen fiber obtained in the step (5) at 150 ℃ for 10 minutes, and then performing calendaring molding on a calendar at 160 ℃ to obtain the collagen fiber modified PVC composite material.

Example 6

This example refers to the preparation of example 5, with the only difference that: and 6, banburying 100 parts of PVC, 20 parts of DOP, 5 parts of AC and 25 parts of collagen fibers obtained in the step (5) at 150 ℃ for 10 minutes, performing calendaring molding on a calendar at 160 ℃, and heating to 180 ℃ for foaming to obtain the collagen fiber modified foamed PVC composite material.

Example 7

This example refers to the preparation of example 5, with the only difference that: and 2, crushing by using a traditional rotary cutter type crusher at the rotation speed of 5000 rpm for 10 minutes in the operation of step 2, wherein the mesh number of the obtained collagen fibers after crushing is about 80 meshes, the defibration rate is about 36.7 percent, and the equilibrium water absorption rate is 11.37 percent after air conditioning in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50 percent) for 48 hours.

Example 8

This example refers to the preparation of example 5, with the only difference that: the third step of micro-denaturation was not performed.

Comparative example 1

Comparative example 1 provides a blank PE: and extruding and molding the PE in a double-screw extruder.

Comparative example 2

Comparative example 2 provides a blank PS: 100 parts of PS and 5 parts of white oil are mixed at 200 ℃ for 15 minutes and then injection molded.

Comparative example 3

Comparative example 3 provides a blank foamed SBS: 100 parts SBS, 5 parts AC and 3 parts sulphur were open-milled at 140 ℃ for 10 minutes and then vulcanized and foamed on a press for 30 minutes at 180 ℃.

Comparative example 4

Comparative example 4 provides a blank MF powder hot pressed at 180 ℃ under 15MPa for 15 minutes.

Comparative example 5

Comparative example 5 provides a blank PVC: 100 parts of PVC and 20 parts of DOP are banburying at 150 ℃ for 5 minutes, and then are calendered and formed on a calender at 160 ℃.

Comparative example 6

Comparative example 6 provides a blank foamed PVC: 100 parts of PVC, 20 parts of DOP and 5 parts of AC are banburied for 5 minutes at 150 ℃, and are subjected to calendaring molding on a calendar at 160 ℃ and then are heated to 180 ℃ for foaming.

Comparative example 7

Comparative example 7 provides wood flour modified PVC: 100 parts of PVC, 20 parts of DOP and 25 parts of wood flour are banburied for 10 minutes at 150 ℃, and then are subjected to calendering molding on a calender at 160 ℃ to obtain the wood flour modified PVC composite material.

Comparative example 8

Comparative example 8 provides stone dust modified PE: the preparation process is referred to comparative example 7, differing only in that: replacing wood powder with stone powder to obtain the stone powder modified PVC composite material.

Comparative example 9

This example refers to the preparation of example 5, with the only difference that: in the operation of the step 2, the collagen fiber is treated by an excessive force chemical activation means, a cutting type force chemical reactor is used, the rotating speed is 30000 rpm, the aperture of a screen mesh is 0.01 mm, the mesh number of the activated collagen fiber is about 3000 meshes, the defibration rate is about 86.45%, and the water absorption rate is 16.73% after the collagen fiber is subjected to air conditioning in a standard temperature and humidity atmosphere (the temperature is 25 ℃ and the humidity is 50%) for 48 hours.

Examples of the experiments

The composite materials prepared in the above examples and comparative examples were cut into wafers of phi 5cm, and compression experiments were performed in an instron universal material testing machine (5984) under a pressure of 4MPa for a compression time of 1800s and a relaxation time of 1800s, and the change of the deformation rate of the material with time was recorded. The results are shown in Table 1. The deformation curves of the materials of examples 5-6 and comparative examples 5-8 are shown in FIG. 1.

TABLE 1

。

As can be seen by combining the table 1 and the figure 1, the irreversible deformation of the composite material obtained by blending the modified collagen fibers and the high polymer is effectively reduced, the reversible deformation ratio is effectively improved, and the creep resistance and the rebound resilience of the composite material are improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The creep-resistant composite material is characterized by comprising thermoplastic high polymer and modified collagen fiber which are mixed according to the weight ratio of 100 (1-100);

2. The creep-resistant composite material of claim 1, wherein the thermoplastic polymer is a polymeric material that can be processed by melt thermoplasticity and has a processing temperature not higher than the dry heat denaturation temperature of the collagen fibers;

preferably, the thermoplastic polymer includes, but is not limited to, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyacetal, polyether, acrylate polymer, thermoplastic polyester, thermoplastic polyurethane, hexamethylolmelamine.

3. The creep-resistant composite material of claim 1, wherein the modified collagen fibers are prepared by crushing or mechanochemical activating pretreated collagen fibers to 2-2500 meshes;

preferably, the pulverization or mechanochemical activation treatment is 32-300 mesh.

4. The creep-resistant composite of claim 3, wherein the pretreated collagen fibers are water-washed, dried collagen fibers;

5. A method for preparing a creep-resistant composite material as claimed in any one of claims 1 to 4, comprising blending the modified collagen fibres with a thermoplastic polymer.

6. The method of claim 5, wherein the modification treatment comprises: crushing or performing mechanochemical activation treatment on the pretreated collagen fibers to 2-2500 meshes, preferably 32-300 meshes;

the pretreatment comprises washing and drying the collagen fibers.

7. The method according to claim 6, wherein the modification treatment further comprises a micro-denaturation treatment and/or a coupling agent modification treatment after the pulverization or mechanochemical activation treatment.

8. The method of claim 7, wherein the micro-denaturing treatment is to place the collagen fibers in an air or solvent environment and heat at 20-240 ℃ for 5 minutes-30 days;

preferably, the heating is carried out for 15-90 minutes at 75-160 ℃;

preferably, the heating is microwave heating or direct heating.

9. The method of claim 8, wherein the coupling agent used for the coupling agent modification comprises any one or more of silanes, titanates, aluminates, organochromium complexes, borides, phosphates, zirconates, stannates, epoxidized soybean oil.

10. The method according to claim 9, wherein the amount of the coupling agent is 0.5% to 20%, preferably 3% to 10%, of the amount of the collagen fiber.