阅读说明：本技术 一种石墨烯橡胶高分子阻燃复合发泡材料及其制备方法 (Graphene rubber high-molecular flame-retardant composite foam material and preparation method thereof ) 是由 丁天宁 丁德材 丁幼丝 陈丹青 于 2019-12-10 设计创作，主要内容包括：本发明公开一种石墨烯橡胶高分子阻燃复合发泡材料及其制备方法,由包括以下重量份的原料制成：天然橡胶50～60份、顺丁橡胶13～17份、三元乙丙橡胶4～6份、白炭黑4～6份、阻燃剂14～17份、石墨烯1.8～2.4份、纳米介质4～6份、氧化锌2～3份、热稳定剂2.5～4份、交联剂2～2.4份、流动助剂3～4份、发泡剂2～2.4份；阻燃剂为二乙基次膦酸锌、磷酸三苯酯的混合物。该石墨烯橡胶高分子阻燃复合发泡材料的阻燃测试达UL-94V0级,且氧指数远高于普通天然橡胶发泡材料；密度低于普通天然橡胶发泡材料,具有超轻性；拉伸强度大幅优于普通天然橡胶发泡材料,力学性能好,很好地兼顾了超轻性和优良的力学性能。(The invention discloses a graphene rubber high-molecular flame-retardant composite foam material and a preparation method thereof, wherein the graphene rubber high-molecular flame-retardant composite foam material is prepared from the following raw materials in parts by weight: 50-60 parts of natural rubber, 13-17 parts of butadiene rubber, 4-6 parts of ethylene propylene diene monomer, 4-6 parts of white carbon black, 14-17 parts of a flame retardant, 1.8-2.4 parts of graphene, 4-6 parts of a nano medium, 2-3 parts of zinc oxide, 2.5-4 parts of a heat stabilizer, 2-2.4 parts of a cross-linking agent, 3-4 parts of a flow assistant and 2-2.4 parts of a foaming agent; the flame retardant is a mixture of zinc diethylphosphinate and triphenyl phosphate. The flame retardant test of the graphene rubber high-molecular flame retardant composite foaming material reaches UL-94V0 level, and the oxygen index is far higher than that of a common natural rubber foaming material; the density is lower than that of the common natural rubber foaming material, and the material has ultra-light weight; the tensile strength is greatly superior to that of the common natural rubber foaming material, the mechanical property is good, and the ultralight property and the excellent mechanical property are well considered.)

1. The graphene rubber high-molecular flame-retardant composite foam material is characterized by being prepared from the following raw materials in parts by weight:

50-60 parts of natural rubber, 13-17 parts of butadiene rubber, 4-6 parts of ethylene propylene diene monomer, 4-6 parts of white carbon black, 14-17 parts of a flame retardant, 1.8-2.4 parts of graphene, 4-6 parts of a nano medium, 2-3 parts of zinc oxide, 2.5-4 parts of a heat stabilizer, 2-2.4 parts of a cross-linking agent, 3-4 parts of a flow assistant and 2-2.4 parts of a foaming agent;

the flame retardant is a mixture of zinc diethylphosphinate and triphenyl phosphate.

2. The graphene rubber high-molecular flame-retardant composite foam material according to claim 1, wherein the graphene rubber high-molecular flame-retardant composite foam material is prepared from the following raw materials in parts by weight:

55 parts of natural rubber, 15 parts of butadiene rubber, 5 parts of ethylene propylene diene monomer, 5 parts of white carbon black, 15 parts of flame retardant, 2 parts of graphene, 5 parts of nano medium, 2.5 parts of zinc oxide, 3.3 parts of heat stabilizer, 2.2 parts of cross-linking agent, 3.5 parts of flow promoter and 2.2 parts of foaming agent; the flame retardant is a mixture of zinc diethylphosphinate and triphenyl phosphate.

3. The graphene rubber high-molecular flame-retardant composite foam material as claimed in claim 1, wherein the mass ratio of zinc diethylphosphinate to triphenyl phosphate in the mixture of zinc diethylphosphinate and triphenyl phosphate is 10: (23-27).

4. The graphene rubber high-molecular flame-retardant composite foam material as claimed in claim 1, wherein the graphene is reduced graphene oxide.

5. The graphene rubber high-molecular flame-retardant composite foam material as claimed in claim 1, wherein the nano medium is nano calcium carbonate.

6. The graphene rubber high-molecular flame-retardant composite foam material as claimed in claim 1, wherein the heat stabilizer is a mixture of zinc stearate and stearic acid; the mass ratio of the zinc stearate to the stearic acid in the mixture of the zinc stearate and the stearic acid is 10: (7-8.5).

7. The graphene rubber high-molecular flame-retardant composite foaming material of claim 1, wherein the crosslinking agent is a rubber crosslinking agent VP-4L.

8. The graphene rubber high-molecular flame-retardant composite foam material as claimed in claim 1, wherein the flow assistant is ethylene bis stearamide.

9. The graphene rubber high-molecular flame-retardant composite foam material as claimed in claim 1, wherein the foaming agent is an AC foaming agent.

10. The preparation method of the graphene rubber high-molecular flame-retardant composite foam material as claimed in any one of claims 1 to 9, which is characterized by comprising the following steps:

A. respectively weighing natural rubber, butadiene rubber, ethylene propylene diene monomer, white carbon black, a flame retardant, graphene, a nano medium, zinc oxide, a heat stabilizer, a cross-linking agent, a flow assistant and a foaming agent according to parts by weight;

B. feeding natural rubber into an internal mixer, masticating for 13-15 min at the temperature of 142-146 ℃, and discharging; storing the masticated natural rubber at room temperature for more than 50h for later use;

C. b, feeding the natural rubber subjected to the mastication treatment in the step B, butadiene rubber, ethylene propylene diene monomer, white carbon black, a flame retardant, graphene, a nano medium, zinc oxide, a heat stabilizer and a flow aid into an internal mixer, and internally mixing for 12-15 min at the temperature of 85-90 ℃; then banburying for 9-12 min at the temperature of 104-108 ℃; then adding a cross-linking agent and a foaming agent, banburying at the temperature of 115-120 ℃ for 8-10 min, and discharging to obtain a banburying rubber mixture;

D. c, conveying the banburying rubber mixture obtained in the step C into an open mill, thinning for 2-4 times on the open mill, and discharging to obtain an open mill rubber mixture;

and finally, feeding the open-mill rubber mixture into a mold for hot-pressing foaming, cooling and molding, and cutting a sample to obtain the graphene rubber high-molecular flame-retardant composite foam material.

Technical Field

The invention relates to the technical field of rubber products, in particular to a graphene rubber high-molecular flame-retardant composite foam material and a preparation method thereof.

Background

Natural Rubber (NR) is a natural polymer compound containing cis-1, 4-polyisoprene as a main component, 91 to 94% of which is rubber hydrocarbon (cis-1, 4-polyisoprene), and the balance of which is non-rubber substances such as protein, fatty acid, ash, saccharides and the like. The material is generally a flaky solid, has the relative density of 0.94, the refractive index of 1.522 and the elastic modulus of 2-4 MPa, is softened at 130-140 ℃, is sticky and soft at 150-160 ℃, and begins to degrade at 200 ℃. Has high elasticity and slight plasticity at normal temperature and is crystallized and hardened at low temperature. Has better alkali resistance but does not resist strong acid. Is insoluble in water, lower ketones and alcohols, and can swell in nonpolar solvents such as chloroform, carbon tetrachloride, etc.

The natural rubber mainly has a macromolecular chain structure, the molecular weight, the distribution and aggregation structure of the molecular weight, the macromolecular chain structural unit of the natural rubber is isoprene, the macromolecular chain is mainly composed of polyisoolefine, the content of the rubber accounts for more than ninety-seven percent, aldehyde groups are arranged on the molecular chain, one aldehyde group is arranged on each macromolecular chain on average, just condensation or reaction with a protein decomposition product is carried out on the aldehyde groups to form branching and crosslinking, so that the viscosity of the rubber in storage is increased, and epoxy groups are arranged on the macromolecular chains of the natural rubber and are more active. The macromolecule end of the natural rubber is generally inferred to be dimethylallyl, the other end of the natural rubber is pyrophosphate, a terminal group, aldehyde group of a molecular chain and polymeric elements are few, the molecular weight range of the natural rubber is wide in the aspects of the molecular weight and the distribution of the molecular weight, the vast majority of the molecular weight is about thirty thousand according to the report from abroad, the strength of the natural raw rubber, the rubber compound and the vulcanized rubber is higher, and the strength of the general natural rubber can reach three megapascals. The main reason for the high mechanical strength of natural rubber is that it is a self-reinforcing rubber series, which, when stretched, orients the macromolecular chains in the direction of stress to form crystals, which act as reinforcement in the amorphous macromolecular fraction, and the same high strength as that without expansion is due to the close agglomeration of the tiny particles in its internal structure.

Natural rubber is a variety with the best coordination between physical and mechanical properties and processing properties in rubber materials, and is widely applied to the fields of daily life, medical treatment and health, transportation, agriculture, scientific experiments, national defense and the like. With the development of society, people put higher demands on the performance of products, such as: the traditional rubber foaming sole has heavy weight, the wear resistance can not meet the requirement, the heat shrinkage resistance is poor, and the rubber foaming sole is often required to be modified.

The graphene has excellent optical, electrical and mechanical properties, has important application prospects in the aspects of materials science, micro-nano processing, energy, biomedicine, drug delivery and the like, and is considered to be a revolutionary material in the future. In recent years, many studies have been made on modification of rubber materials with graphene, and excellent effects have been obtained. However, in the application process of graphene, the graphene lamellar structure has strong van der waals force or hydrogen bond lamp interaction, so that the graphene lamellar structure is easy to agglomerate and cannot be uniformly and stably dispersed. In general, organic functional groups such as carboxyl, hydroxyl, amino and the like are modified on the surface of the street graphene through chemical grafting, so that the dispersibility of the graphene in a high molecular polymer is improved. However, the method destroys the crystal structure of the graphene, and greatly influences the performance of the graphene.

In addition, the natural rubber foam materials used at present have the following problems:

1. the flame retardance is poor, the requirement of certain application fields on the flame retardance can not be met, or the halogen-containing flame retardant is adopted, so that the environment is not protected, and the flame retardant effect is poor;

2. or the weight is not light enough, the device is heavy and cannot meet the use requirement of ultralight; or the mechanical properties such as tensile strength and elongation at break after foaming are poor.

In short, both ultra-light weight and excellent mechanical properties cannot be achieved.

Disclosure of Invention

Based on the above situation, the invention aims to provide a graphene rubber high-molecular flame-retardant composite foam material and a preparation method thereof, which can effectively solve the above problems.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the graphene rubber high-molecular flame-retardant composite foam material is prepared from the following raw materials in parts by weight:

50-60 parts of natural rubber, 13-17 parts of butadiene rubber, 4-6 parts of ethylene propylene diene monomer, 4-6 parts of white carbon black, 14-17 parts of a flame retardant, 1.8-2.4 parts of graphene, 4-6 parts of a nano medium, 2-3 parts of zinc oxide, 2.5-4 parts of a heat stabilizer, 2-2.4 parts of a cross-linking agent, 3-4 parts of a flow assistant and 2-2.4 parts of a foaming agent;

the flame retardant is a mixture of zinc diethylphosphinate and triphenyl phosphate.

Preferably, the graphene rubber high-molecular flame-retardant composite foam material is prepared from the following raw materials in parts by weight:

55 parts of natural rubber, 15 parts of butadiene rubber, 5 parts of ethylene propylene diene monomer, 5 parts of white carbon black, 15 parts of flame retardant, 2 parts of graphene, 5 parts of nano medium, 2.5 parts of zinc oxide, 3.3 parts of heat stabilizer, 2.2 parts of cross-linking agent, 3.5 parts of flow promoter and 2.2 parts of foaming agent; the flame retardant is a mixture of zinc diethylphosphinate and triphenyl phosphate.

Preferably, the mass ratio of the zinc diethylphosphinate to the triphenyl phosphate in the mixture of the zinc diethylphosphinate and the triphenyl phosphate is 10: (23-27).

Preferably, the graphene is reduced graphene oxide.

Preferably, the nano medium is nano calcium carbonate.

Preferably, the heat stabilizer is a mixture of zinc stearate and stearic acid; the mass ratio of the zinc stearate to the stearic acid in the mixture of the zinc stearate and the stearic acid is 10: (7-8.5).

Preferably, the crosslinking agent is a rubber crosslinking agent VP-4L.

Preferably, the flow aid is ethylene bis stearamide.

Preferably, the blowing agent is an AC blowing agent.

The invention also provides a preparation method of the graphene rubber high-molecular flame-retardant composite foam material, which comprises the following steps:

A. respectively weighing natural rubber, butadiene rubber, ethylene propylene diene monomer, white carbon black, a flame retardant, graphene, a nano medium, zinc oxide, a heat stabilizer, a cross-linking agent, a flow assistant and a foaming agent according to parts by weight;

B. feeding natural rubber into an internal mixer, masticating for 13-15 min at the temperature of 142-146 ℃, and discharging; storing the masticated natural rubber at room temperature for more than 50h for later use;

C. b, feeding the natural rubber subjected to the mastication treatment in the step B, butadiene rubber, ethylene propylene diene monomer, white carbon black, a flame retardant, graphene, a nano medium, zinc oxide, a heat stabilizer and a flow aid into an internal mixer, and internally mixing for 12-15 min at the temperature of 85-90 ℃; then banburying for 9-12 min at the temperature of 104-108 ℃; then adding a cross-linking agent and a foaming agent, banburying at the temperature of 115-120 ℃ for 8-10 min, and discharging to obtain a banburying rubber mixture;

D. c, conveying the banburying rubber mixture obtained in the step C into an open mill, thinning for 2-4 times on the open mill, and discharging to obtain an open mill rubber mixture;

E. and finally, feeding the open-mill rubber mixture into a mold for hot-pressing foaming, cooling and molding, and cutting a sample to obtain the graphene rubber high-molecular flame-retardant composite foam material.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the graphene rubber high-molecular flame-retardant composite foaming material disclosed by the invention is prepared by selecting raw materials, optimizing the content of each raw material, and selecting natural rubber, butadiene rubber, ethylene propylene diene monomer, white carbon black, a flame retardant, graphene, a nano medium, zinc oxide, a heat stabilizer, a cross-linking agent, a flow assistant and a foaming agent in a proper ratio, so that the advantages of the raw materials are fully exerted, the raw materials complement each other, the heat stabilizer and the cross-linking agent are mutually promoted, the quality stability of a product is improved, the flame-retardant test of the prepared graphene rubber high-molecular flame-retardant composite foaming material reaches UL-94V0 level, and the oxygen index is far higher than that of a common natural rubber; the density is lower than that of the common natural rubber foaming material, and the material has ultra-light weight; the tensile strength is greatly superior to that of the common natural rubber foaming material, the mechanical property is good, and the ultralight property and the excellent mechanical property are well considered.

The graphene rubber high-molecular flame-retardant composite foaming material disclosed by the invention adopts natural rubber, butadiene rubber and ethylene propylene diene monomer as base materials, so that the mechanical properties such as tensile strength and the like of the graphene rubber high-molecular flame-retardant composite foaming material are well ensured, and the ultralight property and excellent mechanical properties are well considered after foaming.

The appropriate amount of white carbon black is added as a reinforcing agent, the compatibility is good in the raw material system of the invention, the white carbon black is matched with other components to play a good synergistic effect, the tensile strength of the graphene rubber high-molecular flame-retardant composite foaming material can be greatly improved, and the mechanical property is improved.

A proper amount of nano medium, preferably nano calcium carbonate, is added into the raw material system, so that the compatibility is good, the nano medium is matched with other components, a good synergistic effect is achieved, the tensile strength of the graphene rubber high-molecular flame-retardant composite foaming material is further improved, and the mechanical property is improved.

A proper amount of flame retardant is added, preferably a mixture of zinc diethylphosphinate and triphenyl phosphate, in the raw material system, the compatibility with natural rubber, butadiene rubber, ethylene propylene diene monomer and the like is good (good mechanical properties are ensured), the flame retardant property of the graphene rubber high-molecular flame-retardant composite foaming material is greatly improved, and the graphene rubber high-molecular flame-retardant composite foaming material does not contain halogen and is environment-friendly.

The graphene rubber high-molecular flame-retardant composite foaming material has better uniformity and easier uniform dispersion by adding a proper amount of graphene, preferably reduced graphene oxide, can obviously improve the mechanical properties such as strength and the like of the graphene rubber high-molecular flame-retardant composite foaming material, and can greatly improve the wear resistance.

Proper amount of ethylene bis stearamide is added as a flow aid, so that the lubricating oil mainly plays a role in good lubrication, increases the processing fluidity, and improves the processing performance and the apparent performance of products; the compatibility of each component in the raw material system is increased, and the mechanical properties of the material and the like are ensured.

A proper amount of cross-linking agent is added, and the preferable rubber cross-linking agent is VP-4L, so that the graphene rubber high-molecular flame-retardant composite foaming material disclosed by the invention is quickly cross-linked, is moderate in cross-linking, is uniform in cross-linking area distribution, ensures good mechanical properties such as tensile strength and elongation at break of the foamed graphene rubber high-molecular flame-retardant composite foaming material, and well considers ultralight property and excellent mechanical properties.

The preparation method has simple process and simple and convenient operation, and saves manpower and equipment cost.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the following description of the preferred embodiments of the present invention is provided in connection with specific examples, which should not be construed as limiting the present patent.

The test methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials, unless otherwise indicated, are conventionally obtained commercially or prepared by conventional methods.