CN116199946A

CN116199946A - Ultra-high hardness rubber composite material with shape memory function and preparation method and application thereof

Info

Publication number: CN116199946A
Application number: CN202111453972.2A
Authority: CN
Inventors: 张继川; 林金剑; 张立群; 李亮亮
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2023-06-02

Abstract

The invention provides an ultra-high hardness rubber composite material with a shape memory function, and a preparation method and application thereof. The high-hardness rubber composite material with the shape memory function is prepared from raw materials including crystalline rubber and plastic powder; the plastic powder is 1 to 50 parts by weight based on 100 parts by weight of the crystalline rubber. The invention blends the plastic powder and the crystalline rubber to prepare the composite material, which not only improves the hardness of the composite material, but also improves the rigidity of the material, so that the composite material is not easy to deform.

Description

Ultra-high hardness rubber composite material with shape memory function and preparation method and application thereof

Technical Field

The invention relates to the technical field of rubber, in particular to an ultra-high hardness rubber composite material with a shape memory function, and a preparation method and application thereof.

Background

Gutta-percha is a special biological-based polymer material in China, is widely distributed in various areas in China, and has the advantages of being unique, wherein gutta-percha resources in China account for about 99% of the world. Gutta-percha, balata, peach leaf euonymus gum, synthetic trans-1, 4-polyisoprene and other rubbers, the main components of which are trans-polyisoprene, the chemical composition of which is completely the same as that of natural rubber, are polyisoprene, but the molecular chain configurations of the two are different, and the two are isomers.

Shape memory materials refer to materials that have the function of "memorizing" macroscopic shapes, which can be edited or "set" into a particular shape under particular temperature or stress conditions, and then can be restored to their original state under thermal, electrical, or environmental stimuli, etc.

The rubber has the characteristic of the structural order of the trans-chain, so that the molecular chain order degree is higher, the molecular chain can be regularly arranged to form crystals without external force stretching induction at normal temperature, and the molecular chain of the rubber can not freely move after the crystals, so that the rubber is harder at normal temperature and presents a thermoplastic material state.

The method for improving the hardness of the rubber material mainly comprises the step of adding a filler into a rubber matrix. The rigidity of the rubber material can be effectively improved and the hardness can be increased by filling the rubber matrix with hard plasmid-like filler under the normal condition; the hardness of the rubber may be increased by increasing the density of the rubber base material by adding a heavy filler. In filler-rubber composites, there are many factors that affect the hardness of the composite, such as filler particle size, filler-polymer interactions, degree of filler dispersion, and the like. Because the resin and the rubber material are high polymer materials and the resin hardness is generally higher, researchers can adopt the high-hardness crystalline resin to blend with rubber to improve the hardness of a rubber matrix, but in the prior art, the TPV material is prepared by heating and melting and mixing plastic and rubber, the processing temperature is higher, and the hardness of the prepared TPV material is limited. Taking eucommia ulmoides rubber as an example, the original hardness of the eucommia ulmoides rubber is high due to the influence of the crystallization property of the eucommia ulmoides rubber, and the addition of hard plastic to prepare the TPV material can damage the crystallization of the eucommia ulmoides rubber to a certain extent, so that the hardness of the eucommia ulmoides rubber is reduced; and vulcanization also damages a part of the original crystal structure of the eucommia ulmoides rubber. Therefore, the selection of suitable fillers and processing techniques and the control of the proper degree of vulcanization are necessary to increase the hardness of such trans-structured rubbers.

The crystalline rubber can be used for preparing a shape memory characteristic material, the shape of the crystalline rubber can be conveniently adjusted according to the use condition of a person after processing and shaping, for example, a football leg guard board cannot be changed after ordinary material is molded, and the leg guard board cannot be completely attached to the leg due to different legs of each person, and if the crystalline rubber is used for preparing the crystalline rubber, a user can also automatically adjust the crystalline rubber according to the own leg shape, and the leg guard board completely attached to the leg can be obtained. However, the hardness of the material is very high, most of the surfaces of the current material are plastic materials, such as polypropylene, polystyrene, etc., and if the crystalline rubber is used for the material, the hardness of the material should reach at least about 80% of the hardness of the plastic, so that the hardness of the crystalline rubber composite material needs to be greatly improved to be practically used.

Therefore, a method for preparing a composite material by blending crystalline rubber and plastic needs to be studied, so that the hardness of the composite material can be greatly improved, the processing temperature is low, meanwhile, the rigidity of the material can be improved, and the composite material has a shape memory function, so that when the composite material is used for preparing equipment such as protective equipment, the composite material can be adjusted to the most suitable shape according to different requirements of different groups on the shape.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides an ultra-high hardness rubber composite material with a shape memory function, and a preparation method and application thereof.

The invention provides an ultra-high hardness rubber composite material with a shape memory function, which is prepared by blending plastic powder and crystalline rubber, and is different from the processing method commonly used in the prior art, namely, the TPV material is prepared by heating, melting and mixing resin and rubber, so that the hardness of the original matrix rubber material is improved, the rigidity of the material is improved, the material is not easy to deform, and the problem that the reinforcing effect of the general filler on the hardness of the crystalline rubber is not obvious is solved.

The crystallization of the crystalline rubber such as eucommia ulmoides rubber leads to higher hardness, but the hardness is still different from that of common plastics, and when the crystalline rubber is used for sports protection tools and the like, the composite material is required to have the properties of high impact resistance and ultra-high hardness, the pure crystalline rubber material cannot meet the requirements, and the crystalline rubber material is still deficient when used for protection tools and the hardness is required to be further improved. However, it is difficult to improve the hardness of the crystalline rubber again, and the hardness of the crystalline rubber cannot be improved due to the fact that the hard filler generally damages the crystals of the crystalline rubber, and the high-hardness rubber composite material with the shape memory function prepared by the method is more suitable for being applied to sports protection tools while improving the hardness and strength of the crystalline rubber and keeping the original shape memory property of the crystalline rubber.

The shape memory function of the present invention is embodied in: the prepared composite material is in a hard plastic state at normal temperature, and the shape of the composite material cannot be changed; however, when the temperature is increased to above 60 ℃, the crystallization of the material disappears and is obviously softened, the material is fixed to a specific shape, the crystallization reappears after the temperature is reduced, and the shape of the material is fixed to the specific shape; and then the temperature is raised again, the shape of the material returns to the original state.

In the concrete use, the shape memory function of the composite material is embodied in that the protective clothing or the auxiliary tool prepared by the material can be adjusted to the most suitable shape according to different requirements of different people on the shape, for example, a football leg guard plate, the shape cannot be changed after the common material is molded, and because the leg guard plate of each person is different in leg shape, the leg guard plate can not be completely attached to the leg, and if the composite material is used, a user can also automatically adjust according to the leg shape of the user, the leg guard plate completely attached to the leg can be obtained, and the composite material is in a hard plastic state at normal temperature and is convenient to use.

Compared with the prior art, the invention has the advantages that the processing temperature is lower, the melting point of the plastic is not reached, and the operation is simple and convenient; the plastic has wide selection range and controllable cost.

One of the purposes of the invention is to provide an ultra-high hardness rubber composite material with a shape memory function.

The high-hardness rubber composite material with the shape memory function is prepared from raw materials including crystalline rubber and plastic powder;

based on 100 parts by weight of the crystalline rubber,

100 parts by weight of a crystalline rubber;

1-50 parts by weight of plastic powder; preferably 5 to 30 parts by weight; more preferably 15 to 30 parts by weight.

In a preferred embodiment of the present invention,

the melting point of the crystalline rubber is lower than that of the plastic powder. Thus, the plastic can still keep a granular state in the rubber, and the rubber becomes soft after heating, but the plastic does not become soft. The melting point of the crystalline rubber is about 60 ℃, and the melting point of the selected plastic powder is higher than that of the crystalline rubber, so that the plastic powder can be selected.

The plastic powder with the melting point higher than 150 ℃ is preferable, and the plastic powder used in the invention has the melting point higher than 150 ℃ except the melting point of 130 ℃ of polyethylene, because the vulcanization temperature of crystalline rubber is usually 150 ℃ and the melting point higher than 150 ℃ can ensure that the plastic powder still keeps the state of hard plastic powder after being vulcanized at high temperature, and the effect is better, thus being preferable.

In a preferred embodiment of the present invention,

the crystalline rubber is at least one of eucommia ulmoides rubber, gutta-percha, balata gum, peach leaf euonymus gum and synthetic trans-1, 4-polyisoprene; the eucommia ulmoides rubber is natural eucommia ulmoides rubber obtained by extracting eucommia ulmoides seeds and eucommia ulmoides barks, has Mooney viscosity and number average molecular weight of about 23 ten thousand, is softened by heating above 60 ℃, and is crystallized and hardened after the temperature is lower than 60 ℃;

the plastic powder is at least one of polyoxymethylene powder, polytetrafluoroethylene powder, polyethylene powder, polystyrene, polyethylene terephthalate powder, polypropylene powder and polybutylene terephthalate powder; preferably, the softening point of the plastic powder should be above the vulcanization temperature of the crystalline rubber, i.e. typically above 150 ℃; preferably 50-300 μm in particle size; the plastic powder can be prepared by physically crushing the resin synthesized by the prior art, and can also be directly purchased as commercial resin powder.

In a preferred embodiment of the present invention,

the high-hardness rubber composite material with the shape memory function also comprises auxiliary agents commonly used in rubber materials, and preferably comprises an active agent, an anti-aging agent, an accelerator and a vulcanizing agent;

based on 100 parts by weight of the crystalline rubber,

in a preferred embodiment of the present invention,

the active agent is an active agent commonly used in rubber materials in the prior art, preferably at least one of zinc oxide, magnesium oxide and stearic acid; and/or the number of the groups of groups,

the anti-aging agent is commonly used in rubber materials in the prior art, and is preferably at least one of N-phenyl-N '-isopropyl p-phenylenediamine (anti-aging agent 4010 NA), 2, 4-trimethyl-1, 2-dihydroquinoline polymer (anti-aging agent RD), 6-ethoxy-2, 4-trimethyl-1, 2-dihydroquinoline (anti-aging agent AW), N- (1, 3-dimethylbutyl) -N' -phenyl-p-phenylenediamine (anti-aging agent 4020), N-phenyl-alpha-naphthylamine (anti-aging agent A), N-phenyl-beta-naphthylamine (anti-aging agent D), 2,4, 6-tris- (N-1, 4-dimethylpentyl-p-phenylenediamine) -1,3, 5-triazine (anti-aging agent TMPPD) and paraffin; further preferred are at least two, for example, two or three, of the above-mentioned antioxidants.

In a preferred embodiment of the present invention,

the vulcanizing agent is a vulcanizing agent commonly used in rubber materials in the prior art, and is preferably at least one of dicumyl peroxide, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane and sulfur; for example, one or two, etc.; and/or the number of the groups of groups,

the accelerator is accelerator commonly used in rubber materials in the prior art, and is preferably at least one of benzothiazole disulfide (accelerator DM), N-cyclohexyl-2-benzothiazole sulfenamide (accelerator CZ), N-tert-butylbenzothiazole sulfenamide (accelerator DZ), tetramethylthiuram disulfide (accelerator TMTD), tetramethylthiuram monosulfide (accelerator TMTM), dimorpholine disulfide (accelerator DTDM), N-oxydiethylene-2-benzothiazole sulfenamide (accelerator NOBS) and N, N-dicyclohexyl-2-benzothiazole sulfenamide (accelerator NS); further preferred are at least two of the above-mentioned accelerators, for example, two or three.

In the formula of the composite material, other conventional auxiliary agents in the field, such as: the amount of the toner, the filler reinforcing agent, the plasticizer, etc. is also a conventional amount, and the skilled person can determine according to the actual situation.

Shape memory material is a smart material that can spontaneously change from a temporary shape to an original shape upon external stimulus. Proper crosslinking can keep the good mechanical property of the composite material and obtain excellent shape memory property.

The main origins of the shape memory characteristic of the composite material are selected crystalline rubber such as gutta percha, balata gum and peach leaf euonymus alatus, and the molecular chain structure of the synthesized trans-1, 4-polyisoprene is a trans structure, and the molecular chain has double bonds, chain flexibility and order of the trans chain structure.

Double bonds represent that such rubber can be vulcanized; the flexibility of the chain is the basis on which the elastic chain can be constructed; the ordering of the trans-chain structure indicates that the material is prone to crystallization. Because the order degree of the molecular chains is high, the rubber can be regularly arranged to form crystals without external force stretching induction of the molecular chains at normal temperature, and the molecular chains of the rubber can not freely move after the crystals, so that the rubber presents a harder thermoplastic material state at normal temperature. The crystalline melting point of the rubber is about 60 ℃, and the shape memory property can be regulated and controlled through crystalline melting transition. When the temperature is increased, the crystallization of the rubber is destroyed, molecular chains are entangled and disentangled, the free movement capability of the chains is enhanced, and the material is in a softer rubber state; at this time, the rubber is shaped and cooled to recrystallize, the movement of the molecular chain is limited again, the macroscopic shape of the material is fixed, and at this time, if the rubber is warmed again to break the crystallization, the shape of the material is restored.

The second object of the invention is to provide a preparation method of the ultra-high hardness rubber composite material with the shape memory function, which comprises the following steps:

and mixing and vulcanizing the raw materials including the crystalline rubber and the plastic powder according to the dosage to obtain the high-hardness rubber composite material with the shape memory function.

The preparation method is that the crystalline rubber is firstly softened and plasticated on an open mill at 60-80 ℃, then the active agent and the anti-aging agent are added for mixing, then the plastic powder is added into the rubber for mixing, then the accelerator and the vulcanizing agent are added for mixing, the tablet is produced after mixing evenly, and finally the high-temperature vulcanization is carried out.

The vulcanization temperature is 140-150 ℃;

the vulcanization time is t90 of the rubber material measured on a rotor-free vulcanizing instrument, and the formula and the vulcanization time are different.

The invention further aims to provide the application of the ultra-high hardness rubber composite material with the shape memory function in sports equipment, disabled artificial limb sockets and medical correction appliances.

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

the invention greatly improves the hardness of the gutta-percha rubber under the condition of not affecting the shape memory property of the gutta-percha rubber. In the specific use of the shape memory function, the shape memory function is embodied in that the protective clothing or auxiliary tools prepared from the materials can be adjusted to the most suitable shape according to different requirements of different people on the shape, the composite material can be shaped randomly by crystallization and melting at the temperature of more than 60 ℃, the motion protective clothing capable of being shaped randomly is prepared by adopting the process of mixing and vulcanizing, and the prepared motion protective clothing can be adjusted to the shape most suitable for the users according to different users; the prepared composite material has the properties of high impact resistance and ultra-high hardness, and can meet the practical use requirements of protective equipment.

The invention has the advantages of lower processing temperature, simple and convenient operation and environmental protection. The processing temperature for preparing the TPV material by blending rubber and plastic is above the melting points of plastics and rubber, and the melting point of some plastics can reach 200-300 ℃, but the invention only needs about 150 ℃ because the plastics do not need to reach a molten state; and overcomes the defect that the shape memory property of the crystalline rubber is greatly damaged when the method for manufacturing the TPV by co-melting the plastic and the crystalline rubber is hardened, and the shape memory property of the crystalline rubber is not damaged.

The invention has wide selection range of plastic, controllable cost and addition of plastic powder, accelerates the crystallization speed of the crystalline rubber, reduces the curing time and is beneficial to practical application.

Compared with the prior art, the gutta percha material is a bio-based green renewable resource, the bio-based material can be developed to reduce the consumption of petrochemical resources, reduce environmental pollution and be beneficial to environmental protection.

Drawings

FIG. 1 is a schematic view of a Scanning Electron Microscope (SEM) of brittle fracture surface of a composite material prepared in comparative example 1;

FIG. 2 is a schematic view of a Scanning Electron Microscope (SEM) of brittle fracture surface of the composite material prepared in example 3;

FIG. 3 is an X-ray diffraction chart of the composite materials prepared in examples 1 to 3 and comparative example 1;

the small peaks in the figure are the crystallization peaks of the material;

FIG. 4 is a graph of the shape memory cycle of the composite material prepared in example 5.

Detailed Description

The present invention is described in detail below with reference to the specific drawings and examples, and it is necessary to point out that the following examples are given for further illustration of the present invention only and are not to be construed as limiting the scope of the present invention, since numerous insubstantial modifications and adaptations of the invention to those skilled in the art will still fall within the scope of the present invention.

The raw materials used in the examples and comparative examples are conventional commercially available raw materials;

the raw material information used in the examples and comparative examples is as follows:

eucommia ulmoides rubber with Mooney viscosity of 90+/-15 and number average molecular weight of 25-30 ten thousand;

trans-polyisoprene rubber having a Mooney viscosity of 30.+ -.10 and a number average molecular weight of about 50 ten thousand;

the polyformaldehyde powder is obtained by mechanically crushing 100P granules of DuPont company in the United states into powder (the particle size is 100-150 mu m);

the polyethylene terephthalate powder has the trademark PAPET COOL (particle size of 75-150 μm) of Korean LOTTE CHEMICAL company;

the brand of the polypropylene powder is CLARIANT company 3610 of Germany (the particle size is between 15 and 20 mu m);

the polystyrene powder is named as SM0425 (particle size of about 75 μm) from DuPont company of America;

the brand of polybutylene terephthalate powder is DuPont 6134 powder (particle size between 75 and 150 μm);

the brand of the polypropylene powder is microphone company P875064 (the number average molecular weight is 8000+/-500, the softening point is 150-160 ℃, and the grain diameter is 45-300 mu m);

the polytetrafluoroethylene powder was designated by the name of M29038 (particle size: 5 μm) from Meryer company.

The other raw material small materials are all common commercial products.

The testing method comprises the following steps:

the hardness of the prepared composite material is measured according to GB/T2411-2008 by adopting a Shore durometer type D (D2479-02 type of core silicon valley company);

XRD patterns of the composite material thus obtained were measured by an X-ray diffractometer (Smartlab 3, rigaku Co., japan).

Example 1

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 1 part by weight of polypropylene powder (melting point 160 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing technology comprises the following steps:

taking eucommia ulmoides rubber according to a formula, plasticating the eucommia ulmoides rubber at 70 ℃ by adopting a heatable double-roller open mill, and adding an active agent and an anti-aging agent for mixing after the rubber material is wrapped by rollers; after the mixing is completed, adding plastic powder for mixing in batches; mixing with rubber turning, adding accelerator and vulcanizing agent after mixing plastic powder and rubber uniformly, and making three triangular bags to obtain rubber compound. After the rubber compound is parked for more than 24 hours, the rubber compound is put into a mould to be subjected to compression vulcanization molding reaction, the vulcanization pressure is 3.5Mpa, the vulcanization temperature is 150 ℃, and the vulcanization time is 12 minutes. A rubber composite sheet of a predetermined shape and a thickness of 2mm was obtained.

Example 2

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 5 parts by weight of polypropylene powder (melting point 160 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 3

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 15 parts by weight of polypropylene powder (melting point 160 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 4

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polypropylene powder (melting point 160 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 5

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 50 parts by weight of polypropylene powder (melting point 160 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 6

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 1 part by weight of polyoxymethylene powder (melting point 180 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 7

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 5 parts by weight of polyoxymethylene powder (melting point 180 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 8

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 15 parts by weight of polyoxymethylene powder (melting point 180 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 9

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polyoxymethylene powder (melting point 180 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 10

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 50 parts by weight of polyoxymethylene powder (melting point 180 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 11

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polyethylene terephthalate powder (melting point 280 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 12

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polybutylene terephthalate powder (melting point 230 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 13

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polytetrafluoroethylene powder (melting point 327 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 14

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polyethylene powder (melting point 130 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 15

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polystyrene powder (melting point 243 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 16

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polybutylene terephthalate powder (melting point 230 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; age resister 4010NA 2 weight parts; 0.8 parts by weight of accelerator TMTD; 0.8 parts by weight of dicumyl peroxide.

The vulcanization time was 20 minutes, and the rest of the processing was the same as in example 1.

Example 17

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polypropylene powder (melting point 160 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 1.2 parts by weight of promoter CZ; 1.2 parts of sulfur.

The vulcanization time was 17 minutes and the rest of the processing was the same as in example 1.

Example 18

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 15 parts by weight of polypropylene powder (melting point 160 ℃); 15 parts by weight of polyethylene terephthalate powder (melting point 280 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; age resister 4010NA 2 weight parts; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 19

The formula comprises the following components: 100 parts by weight of trans-polyisoprene rubber (melting point 74 ℃); 30 parts by weight of polyoxymethylene powder (melting point 180 ℃); 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in example 1.

Example 20

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polypropylene powder (melting point 160 ℃); 1 part by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The vulcanization time was 15 minutes and the rest of the processing was the same as in example 1.

Example 21

The formula comprises the following components: 100 parts by weight of eucommia ulmoides rubber (melting point 60 ℃); 30 parts by weight of polypropylene powder (melting point 160 ℃); 2 parts by weight of zinc oxide; 2 parts by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The vulcanization time was 10 minutes, and the rest of the processing was the same as in example 1.

Comparative example 1

No stiffening filler is added.

The formula comprises the following components: 100 parts of eucommia ulmoides rubber; 2 parts by weight of zinc oxide; 1 part by weight of stearic acid; 1 part by weight of an anti-aging agent 4010 NA; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing technology comprises the following steps:

taking eucommia ulmoides rubber according to a formula, plasticating the eucommia ulmoides rubber at 70 ℃ by adopting a heatable double-roller open mill, and adding an active agent and an anti-aging agent for mixing after the rubber material is wrapped by rollers; adding accelerator and vulcanizing agent after mixing, mixing with rubber turning operation, and making into three triangular bags to obtain pure eucommia ulmoides rubber compound. After the rubber compound is parked for more than 24 hours, the rubber compound is put into a mould to be subjected to compression vulcanization molding reaction, the vulcanization pressure is 3.5Mpa, the vulcanization temperature is 150 ℃, and the vulcanization time is 12 minutes. To obtain a vulcanized eucommia ulmoides rubber sheet with a predetermined shape and a thickness of 2 mm.

Comparative example 2

The filler is 30 parts of talcum powder.

The formula comprises the following components: 100 parts of eucommia ulmoides rubber; 2 parts by weight of zinc oxide; 30 parts of talcum powder; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in comparative example 1.

Comparative example 3

The filler is 1 part of nucleating agent HX-3.

The formula comprises the following components: 100 parts of eucommia ulmoides rubber; 2 parts by weight of zinc oxide; nucleating agent HX-3 1 parts by weight; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in comparative example 1.

Comparative example 4

The filler is 15 parts of nucleating agent HX-3.

The formula comprises the following components: 100 parts of eucommia ulmoides rubber; 2 parts by weight of zinc oxide; nucleating agent HX-3 15 weight portions; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in comparative example 1.

Comparative example 5

The filler is 1 part of nucleating agent HX-3.

The formula comprises the following components: 100 parts of eucommia ulmoides rubber; 2 parts by weight of zinc oxide; nucleating agent HX-3 weight portions; 1 part by weight of stearic acid; anti-aging agent 4010NA1 weight portion; 0.8 parts by weight of promoter CZ; 0.8 parts of sulfur.

The processing procedure was the same as in comparative example 1.

As can be seen from fig. 1 and 2, in example 3, 30 parts of polypropylene powder is added into eucommia ulmoides rubber, the polypropylene powder has good dispersibility in the eucommia ulmoides rubber matrix, and no larger agglomerates appear, which indicates that the polypropylene powder has high feasibility for reinforcing the eucommia ulmoides rubber.

Fig. 3 is an X-ray diffraction chart of examples 1 to 3 and comparative example 1, and it can be seen from fig. 3 that with the addition of the polypropylene powder, diffraction peaks of the polypropylene powder appear on the chart, the intensity of the diffraction peaks become stronger with the increase of the use amount of the polypropylene powder, indicating that the addition of the plastic powder does not react with the rubber matrix, the hardness enhancement function is a physical effect, and that the powder is added into the gutta percha matrix and there is no adverse reaction with each other.

The Shore D hardness values at 25℃of examples 1 to 21 are shown in Table 1.

The Shore D hardness values at 25℃of comparative examples 1 to 5 are shown in Table 2.

Table 1 examples 1 to 21 have shore D hardness values at 25 °c

Examples numbering	1	2	3	4	5	6	7	8	9	10	11
												Shore D hardness	41	42	44	48	53	41	42	43	46	49	46
Examples numbering	11	12	13	14	15	16	17	18	19	20	21
												Shore D hardness	46	47	47	46	46	47	47	48	47	47	47

Table 2 comparative examples 1-5 Shore D hardness values at 25℃

Comparative example number	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5
						Shore D hardness	39	41	40	42	42

The plastic powders of example 1 and example 6 were used in an amount of 1 part by weight, and the hardness was higher than that of comparative example 1, and it was comparable to comparative example 2, indicating that the hardness of the material was increased by adding the resin powder, but the hardness was not significantly increased when the amount was small; the amounts of the plastic powders used in examples 6 and 10 were 50 parts by weight, and the hardness was remarkably improved, but the fillers were easily removed when the plastic powders were bent and torn, and the application was hindered, so that the amounts of the plastic powders were not too high.

The hardness of example 3 and example 8 (15 parts of plastic powder) is significantly higher than that of comparative example 4 (15 parts of nucleating agent); the plastic powders of examples 4, 9 and 11-21 were all 30 parts, the nucleating agent HX-3 of comparative example 5 was 30 parts, and the hardening effect of the examples was significantly better than that of the comparative examples.

Therefore, the hardness of the composite material can be effectively improved by adding the plastic powder, the hardness of the composite material is positively correlated with the dosage of the plastic powder, the reinforcing effect is achieved by adding 1 part of the plastic powder, the reinforcing effect is good when 5 parts of the plastic powder is added, the hardness of the composite material is improved by 14 compared with that of the composite material in comparative example 1 without the filler when 50 parts of the plastic powder is added, and the hardness improving effect is very obvious according to the evaluation of the industry standard. However, since the plastic is added into the rubber matrix in the form of powder and the processing temperature is below the melting point of the plastic, the plastic is still in a granular state in the rubber matrix; after the tensile test, when the addition amount of the plastic exceeds 30 parts, the matrix in the rubber is easy to fall off under the action of stretching, and the use experience is affected, so that the combination of the hardening effect and the use performance is preferable, and the addition amount of the resin is 5-30 parts.

When the plastic powder exceeds 50 parts, the filler in the composite material is easy to fall off when the material is subjected to large deformation such as 180 DEG bending and high-strength stretching tearing during use, so that the application and use are inconvenient, and in addition, the material is difficult to manufacture and the hardness is not greatly improved after the plastic powder exceeds 50 parts, so that the addition amount is controlled below 50 parts.

The addition of the inorganic filler is a common hardening method for rubber, and as can be seen from comparative examples 1 and 2, the hardening effect of the inorganic filler on the crystalline rubber is not very good, and the addition of the inorganic filler has a lower hardening degree on the eucommia ulmoides rubber than that of the plastic powder.

The addition of nucleating agents to promote increased crystallinity in crystalline materials is also a common and effective way of stiffening crystalline materials, as the degree of crystallinity increases, the intermolecular forces of the material increase, and macroscopic manifestations of the material become stiffer. As can be seen from comparison of example 1, example 6 with comparative example 3, example 8 and comparative example 4, the addition of the conventional nucleating agent does indeed increase the hardness of the crystalline rubber to some extent, but to a lesser extent than the addition of the same amount of the plastic powder, and it can be seen from comparative examples 3 to 5 that there is a significant limit in increasing the hardness by the addition of the nucleating agent because the crystallization degree of the crystalline rubber is increased to some extent, the crystallization degree of the re-addition of the nucleating agent is not changed any more, and the hardness of the material is not increased any more, compared with the stiffening effect of the plastic powder.

In addition, the composite materials prepared in examples 1 to 21 were used as a thermally-induced shape memory material, and were able to respond to temperature changes. The initial shape of the sample at room temperature without acting force is rectangular; the material can be shaped to a temporary shape at will at the moment when the material is placed in hot water at 65 ℃ for soaking for 2-3 minutes, and the temporary shape is fixed in the process of continuously cooling to room temperature; again, the pattern is placed in hot water and the shape of the sample reverts and this thermally induced shape memory behavior is repeatable.

FIG. 4 is a shape memory cycle curve of the high hardness rubber composite prepared in example 5, where the composite crystals disappeared and the material exhibited a rubbery state at 60 ℃; under the condition that 0.9MPa stress is applied, the composite material generates 50% strain; then cooling to crystallize the composite material, and removing stress at 20 ℃, wherein the composite material keeps the strain not reduced because the crystallization limits the movement of molecular chains; and then the temperature is increased, the composite material can return to the original state after the temperature reaches the shape memory transition temperature, and the strain is reduced to 0, so that the high-hardness rubber composite material prepared by the invention has a better shape memory function through the circulation.

According to the test, in the comparative example 1 without adding the plastic powder, the plastic powder is taken out after being soaked in hot water for shaping, the plastic powder is exposed to the environment temperature of 25 ℃ until the hardened shape of the material is completely fixed, 4 minutes are required, the time for completely curing the material is obviously shortened along with the increase of the plastic powder after the plastic powder is added, the curing time of the example 3 is about 3 minutes and 45 seconds, the curing time of the example 4 is about 3 minutes and 30 seconds, and the curing time of the example 5 is about 3 minutes. The addition of the plastic powder accelerates the crystallization speed of the crystalline rubber, reduces the curing time and is beneficial to practical application.

The hardening method of the invention has simple processing and easy raw material acquisition, does not destroy the shape memory property of the crystalline rubber, and overcomes the defect that the shape memory property of the crystalline rubber is greatly damaged when the method for preparing the TPV by co-melting the plastic and the crystalline rubber is hardened.

Claims

1. A high-hardness rubber composite material with a shape memory function is characterized in that:

based on 100 parts by weight of the crystalline rubber,

100 parts by weight of a crystalline rubber;

1-50 parts of plastic powder.

2. The shape memory high hardness rubber composite as claimed in claim 1, wherein:

100 parts by weight of a crystalline rubber;

5-30 parts of plastic powder; preferably 15 to 30 parts by weight.

3. The shape memory high hardness rubber composite as claimed in claim 1, wherein:

the melting point of the crystalline rubber is lower than that of the plastic powder.

4. The shape memory high hardness rubber composite as claimed in claim 1, wherein:

the crystalline rubber is at least one of eucommia ulmoides rubber, gutta-percha, balata gum, peach leaf euonymus gum and synthetic trans-1, 4-polyisoprene; and/or the number of the groups of groups,

the plastic powder is at least one of polyoxymethylene powder, polytetrafluoroethylene powder, polyethylene powder, polystyrene, polyethylene terephthalate powder, polypropylene powder and polybutylene terephthalate powder.

5. The shape memory high hardness rubber composite as claimed in claim 1, wherein:

the high-hardness rubber composite material with the shape memory function also comprises an active agent, an anti-aging agent, an accelerator and a vulcanizing agent;

based on 100 parts by weight of the crystalline rubber,

6. the shape memory high hardness rubber composite as claimed in claim 5, wherein:

7. the shape memory high hardness rubber composite as claimed in claim 5, wherein:

the active agent is at least one of zinc oxide, magnesium oxide and stearic acid; and/or the number of the groups of groups,

the anti-aging agent is at least one of N-phenyl-N '-isopropyl p-phenylenediamine, 2, 4-trimethyl-1, 2-dihydroquinoline polymer, 6-ethoxy-2, 4-trimethyl-1, 2-dihydroquinoline, N- (1, 3-dimethylbutyl) -N' -phenyl-p-phenylenediamine, N-phenyl-alpha-naphthylamine, N-phenyl-beta-naphthylamine, 2,4, 6-tris- (N-1, 4-dimethylpentyl-p-phenylenediamine) -1,3, 5-triazine and paraffin.

8. The shape memory high hardness rubber composite as claimed in claim 5, wherein:

the vulcanizing agent is at least one of dicumyl peroxide, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane and sulfur; and/or the number of the groups of groups,

the accelerator is at least one of benzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tertiary butyl benzothiazole sulfenamide, tetramethylthiuram disulfide, tetramethylthiuram monosulfide, dithiodimorpholine, N-oxydiethylene-2-benzothiazole sulfenamide and N, N-dicyclohexyl-2-2 benzothiazole sulfenamide.

9. A method for producing a high-hardness rubber composite material having a shape memory function as claimed in any one of claims 1 to 8, characterized in that the method comprises:

10. Use of a shape memory high-hardness rubber composite according to any one of claims 1 to 8 or a shape memory high-hardness rubber composite prepared by a method according to claim 9 in sports equipment, prosthetic sockets for disabled persons, medical corrective devices.