Polyolefin elastomer toughened halogen-free heat-resistant material and method for producing the same

Abstract

This invention relates to the field of polymer materials technology, specifically to a toughened halogen-free heat-resistant polyolefin elastomer material and its preparation method. The invention involves mixing ethylene-vinyl acetate copolymer, polyolefin elastomer, polyethylene, compatibilizer, halogen-free flame retardant, flame retardant synergist, antioxidant, and lubricant in a mixer for 10-15 minutes to obtain a mixture. This mixture is then extruded and granulated using a twin-screw extruder and dried to obtain a toughened halogen-free heat-resistant polyolefin elastomer material. This material not only possesses excellent mechanical and flame-retardant properties but also exhibits good heat resistance, allowing it to maintain its mechanical properties even at high temperatures, making it suitable for a wider range of applications.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to halogen-free heat-resistant materials toughened with polyolefin elastomers and their preparation methods. Background Technology

[0002] Polyolefin elastomers (POEs) are high-performance thermoplastic elastomers with advantages such as high elasticity, high strength, high elongation, good low-temperature performance, heat aging resistance, and UV resistance. They can be blended with various polymers to form high-performance composite materials. In the field of halogen-free heat-resistant materials, the toughening effect of POE can improve the toughness of the material, making it less prone to fracture under external impact, while its inherent heat resistance can meet the requirements for use in high-temperature environments.

[0003] Although POE possesses certain heat resistance, its performance may gradually decline under high-temperature conditions, affecting the material's long-term stability and service life. Furthermore, the processing temperature and flowability of POE can influence its performance during processing, leading to difficulties or uneven molding. On the other hand, even with the introduction of flame retardants, the reduced degree of crosslinking prevents the maximization of flame retardant properties. Therefore, addressing these issues by developing a toughened, halogen-free, heat-resistant polyolefin elastomer material is of significant importance. Summary of the Invention

[0004] The purpose of this invention is to provide a toughened halogen-free heat-resistant polyolefin elastomer material and its preparation method, so as to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing a halogen-free heat-resistant material toughened with polyolefin elastomer includes the following steps:

[0007] Ethylene-vinyl acetate copolymer, polyolefin elastomer, polyethylene, compatibilizer, halogen-free flame retardant, flame retardant synergist, antioxidant and lubricant are put into a mixer and mixed for 10-15 minutes to obtain a mixture. The mixture is then extruded and granulated through a twin-screw extruder and dried to obtain a toughened halogen-free heat-resistant polyolefin elastomer material.

[0008] Furthermore, the polyolefin elastomer-toughened halogen-free heat-resistant material comprises the following components by weight: 40-50 parts of ethylene-vinyl acetate copolymer, 15-30 parts of polyolefin elastomer, 30-40 parts of polyethylene, 10-20 parts of compatibilizer, 50-60 parts of halogen-free flame retardant, 10-20 parts of flame retardant synergist, 1-3 parts of lubricant, and 1-2 parts of antioxidant.

[0009] Furthermore, the compatibilizer is one or more of the following: maleic anhydride-grafted polyethylene, maleic anhydride-grafted ethylene vinyl acetate, maleic anhydride-grafted ethylene octene copolymer, and ethylene acrylate-maleic anhydride terpolymer.

[0010] Furthermore, the halogen-free flame retardant is a blend of organosilicon flame retardant and aluminum hydroxide in a mass ratio of 1:(3-5).

[0011] Furthermore, the preparation method of the organosilicon flame retardant is as follows:

[0012] Step 1: Under nitrogen protection, the phosphorus-containing diamine monomer, 2-chloro-4,6-diamino-1,3,5-triazine, triethylamine and chloroform are mixed evenly and reacted in an ice-water bath for 1-3 hours. Then, the mixture is heated to reflux for 3-5 hours. After filtration, washing and drying, the phosphorus-containing triazine intermediate is obtained.

[0013] Step 2: Under nitrogen protection, diphenylsilanediol, vinyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and toluene are mixed evenly, barium hydroxide monohydrate is added, the temperature is raised to 65-75℃ and reacted for 3-5 hours, then the temperature is raised to 80-85℃ and reacted for 4-6 hours, cooled to room temperature, and distilled under reduced pressure to obtain epoxy vinyl organosilicon;

[0014] Step 3: Mix the triazine phosphorus intermediate, epoxy vinyl organosilicon and dimethyl sulfoxide evenly, react at 40-50℃ for 4-6 hours, introduce nitrogen gas, add boric acid solution dropwise over 1-2 hours, raise the temperature to 70-80℃ and react for 8-10 hours. After the reaction is complete, rotary evaporate and vacuum dry to obtain the organosilicon flame retardant.

[0015] Further, in step one, the mass ratio of the phosphorus-containing diamine monomer, 2-chloro-4,6-diamino-1,3,5-triazine, triethylamine and chloroform is 1:(0.4-0.6):(0.3-0.5):(2-4).

[0016] Further, in step two, the mass ratio of diphenylsilanediol, vinyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and toluene is 1:(0.4-0.5):(0.15-0.20):(0.4-0.6).

[0017] Furthermore, in step two, the mass of the barium hydroxide monohydrate is 0.1-0.3% of the mass of diphenylsilanediol.

[0018] Furthermore, in step three, the mass ratio of the phosphorus-containing triazine intermediate, epoxy vinyl organosilicon, and dimethyl sulfoxide is 1:(0.5-1.5):(2-4).

[0019] Furthermore, the concentration of the boric acid solution is 3-5 wt%, and the amount used is 30-40% of the mass of the epoxy vinyl silicone.

[0020] Furthermore, the preparation method of the phosphorus-containing diamine monomer is as follows: under nitrogen protection, p-phenylenediamine, triethylamine and chloroform are mixed evenly, and a mixed solution of phenylphosphodichloride and chloroform is added dropwise in an ice-water bath over 1-2 hours. The mixture is then heated and refluxed for 6-8 hours. After filtration, washing and drying, the phosphorus-containing diamine monomer is obtained.

[0021] Furthermore, the mass ratio of p-phenylenediamine, triethylamine, and chloroform is 1:(1.8-2.0):(5-7).

[0022] Furthermore, the mass ratio of phenylphosphodichloro to trichloromethane is 1:(2-3).

[0023] Further, the mass of the phenylphosphodichloro is 0.75-0.85 of the mass of p-phenylenediamine.

[0024] Furthermore, the flame retardant synergist is a high-viscosity organosilicon mixture.

[0025] Furthermore, the lubricant is one or a mixture of zinc stearate, calcium stearate, and polyethylene wax.

[0026] Furthermore, the antioxidant is antioxidant 1010.

[0027] Furthermore, the mixing temperature is 150-160℃.

[0028] Furthermore, the seven temperature ranges of the twin-screw extruder are 130℃, 145℃, 155℃, 160℃, 165℃, 160℃, and 155℃.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] This invention discloses a toughened, halogen-free, heat-resistant polyolefin elastomer material and its preparation method. A flame retardant with a PN-bonded expansion structure and active dual-terminated amino groups, namely a phosphorus-containing diamine monomer, is synthesized by reacting p-phenylenediamine with phenylphosphine dichloride. This structure effectively improves the flame retardant properties of the material because phosphorus can form phosphates at high temperatures, preventing flame propagation, and nitrogen can release nitrogen gas, diluting combustion gases and reducing the combustion rate. Furthermore, the phosphorus-containing diamine monomer is reacted with 2-chloro-4,6-diamino-1,3,5-triazine to introduce multiple amino groups and a triazine ring skeleton, yielding a phosphorus-containing triazine intermediate. The triazine ring, as a structure with good thermal stability, can improve the thermal stability and flame retardant properties of the material. The method utilizes 3-(2,3-epoxypropoxy) A phenyl organosilicon resin containing epoxy groups, namely epoxy vinyl organosilicon, was prepared by using propyltrimethoxysilane (KH560), diphenylsilanediol, and vinyltrimethoxysilane as raw materials under the catalysis of barium hydroxide monohydrate. Finally, the vinyl group was introduced into the epoxy vinyl organosilicon by reacting the amino group of the triazine phosphorus intermediate with the resin, which enhanced the compatibility of the material and made the final product more dispersed and uniform in the polyolefin matrix, thereby improving the overall performance. In addition, the addition of boric acid to introduce boron element can further enhance the flame retardant properties of the material. Boron compounds can form a protective glass transition layer during combustion, preventing the transfer of heat and oxygen, thereby improving the flame retardant effect. Finally, an organosilicon flame retardant containing N, P, and B flame retardant elements was obtained.

[0031] This invention employs a compound of organosilicon flame retardant and aluminum hydroxide, with the addition of a high-viscosity organosilicon mixture as a flame retardant synergist. This synergist exhibits good compatibility with the organosilicon flame retardant and can work in conjunction with other flame-retardant components to further enhance the flame-retardant performance of the material. This approach allows for the achievement of good flame-retardant effects with a smaller weight of the flame retardant, while significantly improving the material's heat resistance life. Furthermore, the high-viscosity organosilicon mixture can form a continuous phase within the material, contributing to improved processability, flowability, and stability under high-temperature conditions. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] All parts in the following examples are by weight. It should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include (in this example) ethylene-vinyl acetate copolymer: Hanwha Chemical 1828; polyethylene: high-density polyethylene, Lotte Chemical 2600F; polyolefin elastomer: VERSIFYPOE 2300, Dow Chemical; compatibilizer: maleic anhydride grafted polyethylene, DuPont E528; aluminum hydroxide: Chalco H-WF-8; lubricant: Honeywell polyethylene wax AC-6; antioxidant: antioxidant 1010; flame retardant synergist: SFR100 high-viscosity silicone mixture produced by GE Toshiba Silicones Co., Ltd.

[0034] Example 1: A method for preparing a halogen-free heat-resistant material toughened with polyolefin elastomer, comprising the following processes:

[0035] 40 parts of ethylene-vinyl acetate copolymer, 15 parts of polyolefin elastomer, 30 parts of polyethylene, 10 parts of compatibilizer, 50 parts of halogen-free flame retardant (halogen-free flame retardant is a blend of organosilicon flame retardant and aluminum hydroxide in a mass ratio of 1:3), 10 parts of flame retardant synergist, 1 part of antioxidant, and 1 part of lubricant were added to a mixer and mixed at 150°C for 10 minutes to obtain a mixture. The mixture was then extruded and granulated using a twin-screw extruder and dried to obtain a toughened halogen-free heat-resistant polyolefin elastomer material. The seven temperature ranges of the twin-screw extruder were 130°C, 145°C, 155°C, 160°C, 165°C, 160°C, and 155°C.

[0036] The preparation method of organosilicon flame retardant is as follows:

[0037] Step 1: Under nitrogen protection, 15 parts of p-phenylenediamine, 27 parts of triethylamine and 75 parts of chloroform were mixed evenly. Under ice-water bath, a mixed solution of 11.25 parts of phenylphosphodichloro and 22.5 parts of chloroform was added dropwise over 1 hour. The mixture was then heated to reflux for 6 hours. After filtration, washing and drying, the phosphorus-containing diamine monomer was obtained.

[0038] Under nitrogen protection, 15 parts of phosphorus-containing diamine monomer, 6 parts of 2-chloro-4,6-diamino-1,3,5-triazine, 4.5 parts of triethylamine and 30 parts of chloroform were mixed evenly and reacted in an ice-water bath for 1 hour. Then the mixture was heated to reflux for 3 hours. After filtration, washing and drying, phosphorus-containing triazine intermediate was obtained.

[0039] Step 2: Under nitrogen protection, 8 parts of diphenylsilanediol, 3.2 parts of vinyltrimethoxysilane, 1.2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 3.2 parts of toluene were mixed evenly, and 0.008 parts of barium hydroxide monohydrate were added. The mixture was heated to 65°C and reacted for 3 hours, then heated to 80°C and reacted for 4 hours. After cooling to room temperature, the mixture was distilled under reduced pressure to obtain epoxy vinyl organosilicon.

[0040] Step 3: Mix 15 parts of phosphorus triazine intermediate, 7.5 parts of epoxy vinyl organosilicon and 30 parts of dimethyl sulfoxide evenly, react at 40°C for 4 hours, introduce nitrogen gas, add 3wt% boric acid solution dropwise over 1 hour, raise the temperature to 70°C and react for 8 hours. After the reaction is completed, evaporate by rotary evaporation and dry under vacuum to obtain organosilicon flame retardant.

[0041] Example 2: A method for preparing a halogen-free heat-resistant material toughened with polyolefin elastomer, comprising the following processes:

[0042] 45 parts of ethylene-vinyl acetate copolymer, 20 parts of polyolefin elastomer, 35 parts of polyethylene, 15 parts of compatibilizer, 55 parts of halogen-free flame retardant (halogen-free flame retardant is a blend of organosilicon flame retardant and aluminum hydroxide at a mass ratio of 1:4), 15 parts of flame retardant synergist, 1.5 parts of antioxidant, and 2 parts of lubricant were added to a mixer and mixed at 155°C for 12 minutes to obtain a mixture. The mixture was then extruded and granulated using a twin-screw extruder and dried to obtain a toughened halogen-free heat-resistant polyolefin elastomer material. The seven temperature ranges of the twin-screw extruder were 130°C, 145°C, 155°C, 160°C, 165°C, 160°C, and 155°C.

[0043] The preparation method of organosilicon flame retardant is as follows:

[0044] Step 1: Under nitrogen protection, 11 parts of p-phenylenediamine, 20 parts of triethylamine and 66 parts of chloroform were mixed evenly. Under ice-water bath, a mixed solution of 8.8 parts of phenylphosphodichloride and 22 parts of chloroform was added dropwise over 1.5 hours. The mixture was then heated to reflux for 7 hours. After filtration, washing and drying, the phosphorus-containing diamine monomer was obtained.

[0045] Under nitrogen protection, 11 parts of phosphorus-containing diamine monomer, 5.5 parts of 2-chloro-4,6-diamino-1,3,5-triazine, 4.4 parts of triethylamine and 33 parts of chloroform were mixed evenly and reacted in an ice-water bath for 2 h. Then the mixture was heated to reflux for 4 h. After filtration, washing and drying, phosphorus-containing triazine intermediate was obtained.

[0046] Step 2: Under nitrogen protection, 11 parts of diphenylsilanediol, 5 parts of vinyltrimethoxysilane, 2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 5.5 parts of toluene were mixed evenly, and 0.022 parts of barium hydroxide monohydrate were added. The mixture was heated to 70°C and reacted for 4 hours, then heated to 82°C and reacted for 5 hours. After cooling to room temperature, the mixture was distilled under reduced pressure to obtain epoxy vinyl organosilicon.

[0047] Step 3: Mix 11 parts of phosphorus triazine intermediate, 11 parts of epoxy vinyl organosilicon and 33 parts of dimethyl sulfoxide evenly, react at 45°C for 5 hours, introduce nitrogen gas, add 3.8 parts of 4wt% boric acid solution dropwise over 1.5 hours, raise the temperature to 75°C and react for 9 hours. After the reaction is completed, rotary evaporate and vacuum dry to obtain organosilicon flame retardant.

[0048] Example 3: A method for preparing a halogen-free heat-resistant material toughened with polyolefin elastomer, comprising the following processes:

[0049] 50 parts of ethylene-vinyl acetate copolymer, 30 parts of polyolefin elastomer, 40 parts of polyethylene, 20 parts of compatibilizer, 60 parts of halogen-free flame retardant (halogen-free flame retardant is a blend of organosilicon flame retardant and aluminum hydroxide at a mass ratio of 1:5), 20 parts of flame retardant synergist, 2 parts of antioxidant, and 3 parts of lubricant were added to a mixer and mixed at 160°C for 15 minutes to obtain a mixture. The mixture was then extruded and granulated using a twin-screw extruder and dried to obtain a toughened halogen-free heat-resistant polyolefin elastomer material. The seven temperature ranges of the twin-screw extruder were 130°C, 145°C, 155°C, 160°C, 165°C, 160°C, and 155°C.

[0050] The preparation method of organosilicon flame retardant is as follows:

[0051] Step 1: Under nitrogen protection, 10 parts of p-phenylenediamine, 20 parts of triethylamine and 70 parts of chloroform are mixed evenly. Under ice-water bath, a mixed solution of 8.5 parts of phenylphosphodichloro and 25.5 parts of chloroform is added dropwise over 2 hours. The mixture is then heated to reflux for 8 hours. After filtration, washing and drying, a phosphorus-containing diamine monomer is obtained.

[0052] Under nitrogen protection, 10 parts of phosphorus-containing diamine monomer, 6 parts of 2-chloro-4,6-diamino-1,3,5-triazine, 5 parts of triethylamine and chloroform were mixed evenly and reacted in an ice-water bath for 1-3 hours. Then the mixture was heated to reflux for 3-5 hours. After filtration, washing and drying, the phosphorus-containing triazine intermediate was obtained.

[0053] Step 2: Under nitrogen protection, 15 parts of diphenylsilanediol, 7.5 parts of vinyltrimethoxysilane, 3 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 9 parts of toluene were mixed evenly, and 0.045 parts of barium hydroxide monohydrate were added. The mixture was heated to 75°C and reacted for 5 hours, then heated to 85°C and reacted for 6 hours. After cooling to room temperature, the mixture was distilled under reduced pressure to obtain epoxy vinyl organosilicon.

[0054] Step 3: Mix 10 parts of phosphorus triazine intermediate, 15 parts of epoxy vinyl organosilicon and 40 parts of dimethyl sulfoxide evenly, react at 50°C for 6 hours, introduce nitrogen gas, add 6 parts of 5wt% boric acid solution dropwise over 2 hours, raise the temperature to 80°C and react for 10 hours. After the reaction is completed, evaporate by rotary evaporation and dry under vacuum to obtain organosilicon flame retardant.

[0055] Comparative Example 1: Comparative Example 1 is based on Example 2, except that the silicone flame retardant is replaced with the same mass of aluminum hydroxide, and the remaining process steps and reaction parameters are the same as in Example 2.

[0056] A method for preparing halogen-free heat-resistant materials toughened with polyolefin elastomers includes the following processes:

[0057] 45 parts of ethylene-vinyl acetate copolymer, 20 parts of polyolefin elastomer, 35 parts of polyethylene, 15 parts of compatibilizer, 55 parts of halogen-free flame retardant (the halogen-free flame retardant is aluminum hydroxide), 15 parts of flame retardant synergist, 1.5 parts of antioxidant, and 2 parts of lubricant were added to a mixer and mixed at 155°C for 12 minutes to obtain a mixture. The mixture was then extruded and granulated using a twin-screw extruder and dried to obtain a toughened halogen-free heat-resistant polyolefin elastomer material. The seven temperature ranges of the twin-screw extruder were 130°C, 145°C, 155°C, 160°C, 165°C, 160°C, and 155°C.

[0058] Comparative Example 2: Comparative Example 2 is based on Example 2. In Comparative Example 1, the organosilicon flame retardant was replaced with the same mass of phosphorus triazine intermediate. Epoxy vinyl organosilicon and boric acid solution were not introduced. The remaining process steps and reaction parameters were the same as in Example 2.

[0059] The preparation method of the phosphorus triazine intermediate is as follows:

[0060] Under nitrogen protection, 11 parts of p-phenylenediamine, 20 parts of triethylamine and 66 parts of chloroform were mixed evenly. Under ice-water bath, a mixed solution of 8.8 parts of phenylphosphodichloride and 22 parts of chloroform was added dropwise over 1.5 hours. The mixture was then heated to reflux for 7 hours. After filtration, washing and drying, a phosphorus-containing diamine monomer was obtained.

[0061] Under nitrogen protection, 11 parts of phosphorus-containing diamine monomer, 5.5 parts of 2-chloro-4,6-diamino-1,3,5-triazine, 4.4 parts of triethylamine and 33 parts of chloroform were mixed evenly and reacted in an ice-water bath for 2 h. Then the mixture was heated to reflux for 4 h. After filtration, washing and drying, phosphorus-containing triazine intermediate was obtained.

[0062] Comparative Example 3: Comparative Example 3 is based on Example 2, except that the phosphorus triazine intermediate is replaced with the same mass of p-phenylenediamine, and the remaining process steps and reaction parameters are the same as in Example 2.

[0063] The preparation method of organosilicon flame retardant is as follows:

[0064] Step 1: Under nitrogen protection, 11 parts of diphenylsilanediol, 5 parts of vinyltrimethoxysilane, 2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 5.5 parts of toluene were mixed evenly, and 0.022 parts of barium hydroxide monohydrate were added. The mixture was heated to 70°C and reacted for 4 hours, then heated to 82°C and reacted for 5 hours. After cooling to room temperature, the mixture was distilled under reduced pressure to obtain epoxy vinyl organosilicon.

[0065] Step 2: Mix 11 parts of p-phenylenediamine, 11 parts of epoxy vinyl organosilicon and 33 parts of dimethyl sulfoxide evenly, react at 45°C for 5 hours, introduce nitrogen gas, add 3.8 parts of 4wt% boric acid solution dropwise over 1.5 hours, raise the temperature to 75°C and react for 9 hours. After the reaction is complete, rotary evaporate and vacuum dry to obtain organosilicon flame retardant.

[0066] Comparative Example 4: Comparative Example 4 is based on Example 2. In Comparative Example 4, the mass ratio of the phosphorus-containing triazine intermediate to the epoxy vinyl organosilicon is 1:0.2. The remaining process steps and reaction parameters are the same as in Example 2.

[0067] The preparation method of organosilicon flame retardant is as follows:

[0068] Step 1: Under nitrogen protection, 11 parts of p-phenylenediamine, 20 parts of triethylamine and 66 parts of chloroform were mixed evenly. Under ice-water bath, a mixed solution of 8.8 parts of phenylphosphodichloride and 22 parts of chloroform was added dropwise over 1.5 hours. The mixture was then heated to reflux for 7 hours. After filtration, washing and drying, the phosphorus-containing diamine monomer was obtained.

[0069] Under nitrogen protection, 11 parts of phosphorus-containing diamine monomer, 5.5 parts of 2-chloro-4,6-diamino-1,3,5-triazine, 4.4 parts of triethylamine and 33 parts of chloroform were mixed evenly and reacted in an ice-water bath for 2 h. Then the mixture was heated to reflux for 4 h. After filtration, washing and drying, phosphorus-containing triazine intermediate was obtained.

[0070] Step 2: Under nitrogen protection, 11 parts of diphenylsilanediol, 5 parts of vinyltrimethoxysilane, 2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 5.5 parts of toluene were mixed evenly, and 0.022 parts of barium hydroxide monohydrate were added. The mixture was heated to 70°C and reacted for 4 hours, then heated to 82°C and reacted for 5 hours. After cooling to room temperature, the mixture was distilled under reduced pressure to obtain epoxy vinyl organosilicon.

[0071] Step 3: Mix 11 parts of phosphorus triazine intermediate, 2.2 parts of epoxy vinyl organosilicon and 33 parts of dimethyl sulfoxide evenly, react at 45°C for 5 hours, introduce nitrogen gas, add 3.8 parts of 4wt% boric acid solution dropwise over 1.5 hours, raise the temperature to 75°C and react for 9 hours. After the reaction is completed, rotary evaporate and vacuum dry to obtain organosilicon flame retardant.

[0072] Experiment: Samples were prepared from the halogen-free, toughened polyolefin elastomer materials obtained in Examples 1-3 and Comparative Examples 1-4. The properties of these samples were tested, and the results were recorded.

[0073] The oxygen index test was conducted according to GB / T 2406.2-209 "Determination of Combustion Behavior by Oxygen Index Method for Plastics - Part 2: Room Temperature Test", with a sample size of 100mm×6.5mm×3mm. The tensile property test was conducted according to GB / T 1040.3-2006 "Test of Tensile Properties of Plastics", using a universal electronic tensile testing machine at a tensile rate of 50mm / min, with a sample size of 100mm×10mm×1mm. The thermal aging test was conducted by suspending the sample in a thermal aging oven and performing an accelerated thermal aging test at 158℃ for 7 days. The tensile property test was then performed again, and the rate of change in tensile strength was calculated.

[0074] The test results are shown in Table 1.

[0075] Table 1. Test results of various properties of polyolefin elastomer-toughened halogen-free heat-resistant materials

[0076]

[0077] Based on the data in the table above, the following conclusions can be clearly drawn:

[0078] 1. Compared with Examples 1-3, the oxygen index, tensile strength and thermal aging performance of the product obtained in Comparative Example 1 all decreased, indicating that the organosilicon flame retardant prepared by the present invention has better flame retardant effect, thermal stability and compatibility than aluminum hydroxide, thereby effectively improving the flame retardant performance, thermal aging performance and mechanical properties of the material; Comparative Example 2, due to the absence of epoxy vinyl organosilicon and boric acid solution, resulted in a decrease in all properties of the material.

[0079] 2. Compared with Examples 1-3, the oxygen index, tensile strength and thermal aging performance of Comparative Example 3 all decreased. It can be seen that compared with p-phenylenediamine, the phosphorus-containing triazine intermediate prepared by the present invention has better flame retardant properties and thermal stability, thus effectively inhibiting the combustion reaction at high temperature and maintaining good mechanical properties.

[0080] 3. Compared with Examples 1-3, the oxygen index, tensile strength and thermal aging properties of the product obtained in Comparative Example 4 all decreased, indicating that the performance of the material will decrease when the amount of epoxy vinyl silicone added is reduced.

[0081] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. Process for the preparation of polyolefin elastomer toughened halogen-free heat resistant materials, characterized by: Includes the following steps: Ethylene-vinyl acetate copolymer, polyolefin elastomer, polyethylene, compatibilizer, halogen-free flame retardant, flame retardant synergist, antioxidant and lubricant are put into a mixer and mixed for 10-15 minutes to obtain a mixture; the mixture is extruded and granulated through a twin-screw extruder and dried to obtain a polyolefin elastomer toughened halogen-free heat-resistant material. The halogen-free flame retardant is a blend of organosilicon flame retardant and aluminum hydroxide in a mass ratio of 1:(3-5); The preparation method of the organosilicon flame retardant is as follows: Step 1: Under nitrogen protection, the phosphorus-containing diamine monomer, 2-chloro-4,6-diamino-1,3,5-triazine, triethylamine and chloroform are mixed evenly and reacted in an ice-water bath for 1-3 hours. Then, the mixture is heated to reflux for 3-5 hours. After filtration, washing and drying, the phosphorus-containing triazine intermediate is obtained. Step 2: Under nitrogen protection, diphenylsilanediol, vinyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and toluene are mixed evenly, barium hydroxide monohydrate is added, the temperature is raised to 65-75℃ and reacted for 3-5 hours, then the temperature is raised to 80-85℃ and reacted for 4-6 hours, cooled to room temperature, and distilled under reduced pressure to obtain epoxy vinyl organosilicon; Step 3: Mix the triazine phosphorus intermediate, epoxy vinyl organosilicon and dimethyl sulfoxide evenly, react at 40-50℃ for 4-6 hours, introduce nitrogen gas, add boric acid solution dropwise over 1-2 hours, raise the temperature to 70-80℃ and react for 8-10 hours. After the reaction is completed, evaporate by rotary evaporation and dry under vacuum to obtain the organosilicon flame retardant. The preparation method of the phosphorus-containing diamine monomer is as follows: under nitrogen protection, p-phenylenediamine, triethylamine and chloroform are mixed evenly, and a mixed solution of phenylphosphodichloride and chloroform is added dropwise in an ice-water bath. The addition is completed in 1-2 hours, and the mixture is heated and refluxed for 6-8 hours. After filtration, washing and drying, the phosphorus-containing diamine monomer is obtained.

2. The method for preparing the polyolefin elastomer-toughened halogen-free heat-resistant material according to claim 1, characterized in that: The polyolefin elastomer-toughened halogen-free heat-resistant material comprises the following components by weight: 40-50 parts of ethylene-vinyl acetate copolymer, 15-30 parts of polyolefin elastomer, 30-40 parts of polyethylene, 10-20 parts of compatibilizer, 50-60 parts of halogen-free flame retardant, 10-20 parts of flame retardant synergist, 1-3 parts of lubricant, and 1-2 parts of antioxidant.

3. The method for preparing the polyolefin elastomer-toughened halogen-free heat-resistant material according to claim 1, characterized in that: In step one, the mass ratio of the phosphorus-containing diamine monomer, 2-chloro-4,6-diamino-1,3,5-triazine, triethylamine and chloroform is 1:(0.4-0.6):(0.3-0.5):(2-4).

4. The method for preparing the polyolefin elastomer-toughened halogen-free heat-resistant material according to claim 1, characterized in that: In step three, the mass ratio of the phosphorus-containing triazine intermediate, epoxy vinyl organosilicon, and dimethyl sulfoxide is 1:(0.5-1.5):(2-4).

5. The method for preparing the polyolefin elastomer-toughened halogen-free heat-resistant material according to claim 2, characterized in that: The flame retardant synergist is a high-viscosity organosilicon mixture.

6. The method for preparing the polyolefin elastomer-toughened halogen-free heat-resistant material according to claim 2, characterized in that: The lubricant is one or a mixture of zinc stearate, calcium stearate, and polyethylene wax.

7. A halogen-free heat-resistant polyolefin elastomer toughened material prepared by any one of claims 1-6.

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