CN114656702B

CN114656702B - Flame-retardant rubber for building safety net and preparation method thereof

Info

Publication number: CN114656702B
Application number: CN202210507050.3A
Authority: CN
Inventors: 陈真阳; 李志祥; 傅蒙; 吴小波
Original assignee: Anhui Yongzheng Seal Co ltd
Current assignee: Anhui Yongzheng Seal Co ltd
Priority date: 2022-05-10
Filing date: 2022-05-10
Publication date: 2023-06-13
Anticipated expiration: 2042-05-10
Also published as: CN114656702A

Abstract

The invention relates to flame-retardant rubber for a building safety net and a preparation method thereof, which belong to the technical field of rubber materials and comprise the following raw materials in parts by weight: 100 parts of neoprene, 70-80 parts of carbon black, 1-3 parts of a silane coupling agent, 6-8 parts of modified magnesium hydroxide, 2-3 parts of an accelerator, 3-6 parts of castor oil, 3-5 parts of an anti-aging additive and 2-3 parts of sulfur; the preparation method comprises the following steps: adding raw materials into an internal mixer for mixing; the flame-retardant rubber for the building safety net is obtained. According to the invention, azodiisobutyronitrile is used as an initiator to initiate the mixed monomer to polymerize on the surface of magnesium hydroxide to form an organic branched chain, so that the interface property between a polymer material and an inorganic material is improved, the stress concentration and internal defects are reduced, and the mechanical property of the material is excellent; on the premise of maintaining mechanical properties, the flame retardant property of the flame retardant is improved.

Description

Flame-retardant rubber for building safety net and preparation method thereof

Technical Field

The invention belongs to the technical field of rubber materials, and particularly relates to flame-retardant rubber for a building safety net and a preparation method thereof.

Background

The safety net is a net which is arranged under or at the side of the safety net and has a protective effect when building construction, equipment installation or technical performance is carried out at high altitude, so as to prevent accidents caused by falling of people or objects. Generally braided with ropes or the like; the safety net should have the characteristics of high strength, light net body, heat insulation, ventilation, light transmission, fire prevention, dust prevention, noise reduction and the like. The safety net generally comprises net body, side ropes, ropes and other members, and at present, most of the traditional net body is woven by inflammable materials, has no combustibility, does not resist high temperature, and cannot effectively prevent spark and molten metal from burning and damaging the safety net. Although halogen flame retardance, low-halogen low-smoke flame retardance, halogen-free low-smoke flame retardance, green environment-friendly flame retardance and the like are successively presented in the market in the aspect of chemical fiber cable flame retardance and fire prevention technologies, the flame retardance modes have defects and cannot meet the requirements of the current flame retardance and fire prevention market. In addition, the common chloroprene rubber has polarity due to the existence of chlorine atoms, and also forms hydrophilic groups, so that the water resistance of the chloroprene rubber is reduced, and the application range of the chloroprene rubber is influenced.

Disclosure of Invention

In order to solve the technical problems in the background art, the invention provides flame retardant rubber for a building safety net and a preparation method thereof.

The aim of the invention can be achieved by the following technical scheme:

the flame-retardant rubber for the building safety net comprises the following raw materials in parts by weight:

100 parts of neoprene, 70-80 parts of carbon black, 1-3 parts of a silane coupling agent, 6-8 parts of modified magnesium hydroxide, 2-3 parts of an accelerator, 3-6 parts of castor oil, 3-5 parts of an anti-aging additive and 2-3 parts of sulfur;

further, the modified magnesium hydroxide is prepared by the steps of:

step S11, mixing D0P0, 1, 3-dihydroxyacetone and ethylene glycol monomethyl ether under the protection of nitrogen, stirring and reacting for 30min at 90 ℃, heating and refluxing for 4h, decompressing and suction-filtering to obtain a solid crude product after the reaction is finished, and using the mass ratio of 1:1, washing the mixture of ethyl acetate and petroleum ether for three times, and drying the mixture to constant weight under the vacuum condition at 80 ℃ to obtain a hydroxyl monomer;

step S12, mixing a hydroxyl monomer and 4-dimethylaminopyridine under the protection of nitrogen, adding methacrylic anhydride, stirring for 24 hours at the temperature of 45 ℃, cooling to 20 ℃ after the reaction is finished, extracting with dichloromethane, adding saturated sodium bicarbonate for washing until no bubbles are generated, washing with a sodium hydroxide solution, a hydrochloric acid solution and saturated saline water in sequence, drying with anhydrous magnesium sulfate, filtering, performing reduced pressure rotary evaporation, and performing vacuum drying to obtain a monomer a; 2,4, 6-tris (allyloxy) -1,3, 5-triazine as monomer b; monomer a and monomer b are mixed according to a mass ratio of 3:1, mixing to form a mixed monomer; wherein the structure of monomer a is as follows:

and step S13, mixing the primary modified magnesium hydroxide and absolute ethyl alcohol at the temperature of 65 ℃, adding azodiisobutyronitrile and mixed monomers, stirring and reacting for 3 hours, filtering after the reaction is finished, washing with deionized water, and drying after the washing is finished to obtain the modified magnesium hydroxide.

Further, in step S11, the ratio of D0P0, 1, 3-dihydroxyacetone and ethylene glycol monomethyl ether was 0.1mol:0.1mol:100mL;

in the step S12, the using amount and mass ratio of the hydroxyl monomer to the methacrylic anhydride are 5:3.4; the addition amount of the 4-dimethylaminopyridine is 2% of the mass of the hydroxyl monomer;

in the step S13, the addition amount of the azodiisobutyronitrile is 0.4% of the mass of the primary modified magnesium hydroxide, and the mass ratio of the mixed monomer to the primary modified magnesium hydroxide is 3:7.

the azodiisobutyronitrile is used as an initiator to initiate the mixed monomer to polymerize on the surface of the magnesium hydroxide to form an organic branched chain, so that the interface property between the polymer material and the inorganic material is improved.

Further, the primary modified magnesium hydroxide is prepared by the following steps:

mixing deionized water and absolute ethyl alcohol at 60 ℃, adding dimethoxy methyl vinyl silane, stirring for 5min, adding magnesium hydroxide, stirring for 30min, and finally evaporating the solution to obtain primary modified magnesium hydroxide; the volume ratio of deionized water to absolute ethyl alcohol is 1:9, a step of performing the process; the addition amount of the dimethoxy methyl vinyl silicon is 8 percent of the mass of the magnesium hydroxide. The mass ratio of the anhydrous ethanol to the magnesium hydroxide is 2:1. the dimethoxy methyl vinyl silane is utilized to carry out primary modification on the magnesium hydroxide, and double bonds are introduced into the magnesium hydroxide, so that subsequent reactions can be carried out conveniently.

Further, the silane coupling agent is methyltriethoxysilane; promoter selection promoter CZ.

Further, the anti-aging additive is prepared by the steps of:

s21, generating hydrosilylation by allyl glycidyl ether and tetramethyl disiloxane to prepare an epoxy monomer; mixing propenyl glycidyl ether and toluene, adding a Caster catalyst under the protection of nitrogen, heating to 50 ℃, stirring for 50min, then adding tetramethyl disiloxane, heating to 70 ℃ after the addition is finished, continuously stirring for reacting for 48h, and concentrating under reduced pressure to remove a solvent after the reaction is finished to obtain an epoxy monomer;

s22, mixing N-isopropyl-N' -phenyl p-phenylenediamine and an epoxy monomer, adding salicylic acid, reacting for 5 hours at the temperature of 150 ℃, diluting with chloroform after the reaction is finished, washing with sodium bicarbonate aqueous solution and deionized water in sequence, diluting with petroleum ether after the washing is finished, finally removing the solvent by rotary evaporation, and drying to constant weight under the vacuum condition at the temperature of 100 ℃ to obtain the anti-aging additive.

Further, the ratio of the amount of propylene-based glycidyl ether, tetramethyldisiloxane, and the Caster catalyst used in step S21 was 2.3g:1g:0.2mL; in the step S22, the dosage mass ratio of the N-isopropyl-N' -phenyl p-phenylenediamine to the epoxy monomer is 7.2:2.

N-isopropyl-N '-phenyl-p-phenylenediamine in the raw materials for preparing the anti-aging additive is a common anti-aging agent, but is easy to extract by water, has high migration speed, consumes more, has unstable anti-aging performance and affects the use of a safety net, so that the epoxy monomer is prepared by hydrosilylation of propenyl glycidyl ether and tetramethyl disiloxane, and then the anti-aging additive is prepared by addition reaction of the epoxy monomer and N-isopropyl-N' -phenyl-p-phenylenediamine, so that the molecular weight of the anti-aging additive is improved, the migration resistance of the anti-aging additive is further improved, and the water resistance of the anti-aging additive is also improved by introducing organosilicon.

A preparation method of flame retardant rubber for a building safety net comprises the following steps:

adding chloroprene rubber, carbon black, a silane coupling agent, modified magnesium hydroxide, castor oil and an anti-aging additive into an internal mixer; mixing at 130 deg.c and rotor speed of 60-80r/min for 5-8min, adding promoter and sulfur, mixing for 2min and discharging to obtain the fireproof rubber for building safety net.

The invention has the beneficial effects that:

in order to improve the flame retardant property of the flame retardant rubber for the building safety net, the invention selects magnesium hydroxide as the flame retardant, the magnesium hydroxide is the flame retardant with filling effect, and the hardness is increased due to the aggregation phenomenon caused by poor dispersibility; meanwhile, a compound flame-retardant system is formed, and the material components have a certain synergistic flame-retardant effect through reaction or promotion, and act together from a condensed phase and a gas phase; the continuous, compact and stable carbonization layer can be formed in the high-temperature combustion process, the smoke generation amount and the combustible molten drops are reduced, and the action efficiency can be remarkably improved, namely the flame retardant property of the flame retardant is improved on the premise of maintaining the mechanical property.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

Preparation of an anti-aging additive:

s21, generating hydrosilylation by allyl glycidyl ether and tetramethyl disiloxane to prepare an epoxy monomer; mixing propenyl glycidyl ether and toluene, adding a Caster catalyst under the protection of nitrogen, heating to 50 ℃, stirring for 50min, then adding tetramethyl disiloxane, heating to 70 ℃ after the addition is finished, continuously stirring for reacting for 48h, and concentrating under reduced pressure to remove a solvent after the reaction is finished to obtain an epoxy monomer; the dosage ratio of propenyl glycidyl ether, tetramethyl disiloxane and Caster catalyst was 2.3g:1g:0.2mL;

s22, mixing N-isopropyl-N' -phenyl p-phenylenediamine and an epoxy monomer, adding salicylic acid, reacting for 5 hours at the temperature of 150 ℃, diluting with chloroform after the reaction is finished, washing with sodium bicarbonate aqueous solution and deionized water in sequence, diluting with petroleum ether after the washing is finished, finally removing the solvent by rotary evaporation, and drying to constant weight under the vacuum condition at the temperature of 100 ℃ to obtain the anti-aging additive. The dosage mass ratio of the N-isopropyl-N' -phenyl p-phenylenediamine to the epoxy monomer is 7.2:2.

example 2

Preparing modified magnesium hydroxide:

step S11, mixing D0P0, 1, 3-dihydroxyacetone and ethylene glycol monomethyl ether under the protection of nitrogen, stirring and reacting for 30min at 90 ℃, heating and refluxing for 4h, decompressing and suction-filtering to obtain a solid crude product after the reaction is finished, and using the mass ratio of 1:1, washing the mixture of ethyl acetate and petroleum ether for three times, and drying the mixture to constant weight under the vacuum condition at 80 ℃ to obtain a hydroxyl monomer; wherein the dosage ratio of D0P0, 1, 3-dihydroxyacetone and ethylene glycol monomethyl ether is 0.1mol:0.1mol:100mL;

step S12, mixing a hydroxyl monomer and 4-dimethylaminopyridine under the protection of nitrogen, adding methacrylic anhydride, stirring for 24 hours at the temperature of 45 ℃, cooling to 20 ℃ after the reaction is finished, extracting with dichloromethane, adding saturated sodium bicarbonate for washing until no bubbles are generated, washing with a sodium hydroxide solution, a hydrochloric acid solution and saturated saline water in sequence, drying with anhydrous magnesium sulfate, filtering, performing reduced pressure rotary evaporation, and performing vacuum drying to obtain a monomer a; 2,4, 6-tris (allyloxy) -1,3, 5-triazine as monomer b; monomer a and monomer b are mixed according to a mass ratio of 3:1, mixing to form a mixed monomer; the dosage mass ratio of the hydroxyl monomer to the methacrylic anhydride is 5:3.4; the addition amount of the 4-dimethylaminopyridine is 2% of the mass of the hydroxyl monomer;

step S13, mixing deionized water and absolute ethyl alcohol at the temperature of 60 ℃, adding dimethoxy methyl vinyl silane, stirring for 5min, adding magnesium hydroxide, stirring for 30min, and finally evaporating the solution to obtain primary modified magnesium hydroxide; the volume ratio of deionized water to absolute ethyl alcohol is 1:9, a step of performing the process; the addition amount of the dimethoxy methyl vinyl silicon is 8 percent of the mass of the magnesium hydroxide. The mass ratio of the anhydrous ethanol to the magnesium hydroxide is 2:1, a step of; mixing the primary modified magnesium hydroxide and absolute ethyl alcohol at 65 ℃, adding azodiisobutyronitrile and mixed monomers, stirring and reacting for 3 hours, filtering after the reaction is finished, washing with deionized water, and drying after the washing is finished to obtain the modified magnesium hydroxide. The addition amount of the azodiisobutyronitrile is 0.4% of the mass of the primary modified magnesium hydroxide, and the mass ratio of the mixed monomer to the primary modified magnesium hydroxide is 3:7.

example 3

100 parts of neoprene, 70 parts of carbon black, 1 part of methyltriethoxysilane, 6 parts of modified magnesium hydroxide prepared in example 2, 3 parts of castor oil and 3 parts of anti-aging additive prepared in example 1 are added into an internal mixer according to parts by weight; the mixing temperature is 130 ℃, the rotor rotating speed is 60r/min, the time is 5min, then 2 parts of accelerator CZ and 2 parts of sulfur are added on an open mill, mixing is carried out for 2min, and discharging is carried out, thus obtaining the flame retardant rubber for the building safety net.

Example 4

100 parts of neoprene, 75 parts of carbon black, 2 parts of methyltriethoxysilane, 7 parts of the modified magnesium hydroxide prepared in example 2, 5 parts of castor oil and 4 parts of the anti-aging additive prepared in example 1 are added into an internal mixer in parts by weight; the mixing temperature is 130 ℃, the rotor rotating speed is 70r/min, the time is 7min, then 2.5 parts of accelerator CZ and 2.5 parts of sulfur are added on an open mill, the mixing is carried out for 2min, and the material is discharged, so that the flame retardant rubber for the building safety net is obtained.

Example 5

100 parts of neoprene, 80 parts of carbon black, 3 parts of methyltriethoxysilane, 8 parts of modified magnesium hydroxide prepared in example 2, 6 parts of castor oil and 5 parts of anti-aging additive prepared in example 1 are added into an internal mixer according to parts by weight; the mixing temperature is 130 ℃, the rotor rotating speed is 80r/min, the time is 8min, then 3 parts of accelerator CZ and 3 parts of sulfur are added on an open mill, mixing is carried out for 2min, and discharging is carried out, thus obtaining the flame retardant rubber for the building safety net.

Comparative example 1

The modified magnesium hydroxide in example 5 was changed to magnesium hydroxide, and the remaining raw materials and the preparation process were kept unchanged.

Comparative example 2

The anti-aging additive in example 4 was replaced with N-isopropyl-N' -phenyl-p-phenylenediamine, and the remaining raw materials and the preparation process were kept unchanged.

The samples prepared in examples 3-5 and comparative examples 1-2 were tested for vertical burn performance according to GB/T10707-2008 standard spline, and the sample length, width and thickness standards were 130mm by 13mm by 3mm. Combustion performance was classified into 3 classes, FV-0: flame and flameless combustion times less than 30s, no combustible drips: FV-1: flame and flameless combustion times less than 60s and no combustible drips: FV-2: flame and flameless combustion times less than 60s, with combustible drips: and the total combustion time is greater than 60s, and the combustion is not in a combustion grade.

Testing tensile stress strain performance of a sample according to GB/T528-2009, wherein the testing speed is 500mm/min; GB/T529-2008 test sample tearing property; GB/T531-2008 is used for testing the indentation hardness of the sizing material; GB/T3512-2001 test samples, before heat and oxygen aging performance, are placed in water with the same mass, and are extracted in an oven at 60 ℃ at a high speed for 48 hours, and then are taken out.

The test results are shown in table 1 below:

TABLE 1

As can be seen from the above Table 1, the flame retardant rubber for the building safety net prepared by the invention has good mechanical properties, can meet the use requirement, has better mixing effect with raw materials, maintains the performance of the material, and has good flame retardant performance by utilizing the cooperation of organic and inorganic flame retardant raw materials.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is merely illustrative and explanatory of the invention, as various modifications and additions may be made to the particular embodiments described, or in a similar manner, by those skilled in the art, without departing from the scope of the invention or exceeding the scope of the invention as defined in the claims.

Claims

1. The flame-retardant rubber for the building safety net is characterized by comprising the following raw materials in parts by weight:

the modified magnesium hydroxide is prepared by the following steps:

step S11, mixing DOPO, 1, 3-dihydroxyacetone and ethylene glycol monomethyl ether under the protection of nitrogen, stirring at 90 ℃ for reaction for 30min, and then heating and refluxing for reaction for 4h to obtain a hydroxyl monomer;

step S12, mixing a hydroxyl monomer and 4-dimethylaminopyridine under the protection of nitrogen, adding methacrylic anhydride, and stirring for 24 hours at the temperature of 45 ℃ to obtain a monomer a; 2,4, 6-tris (allyloxy) -1,3, 5-triazine as monomer b; mixing the monomer a and the monomer b to form a mixed monomer;

step S13, mixing the primary modified magnesium hydroxide and absolute ethyl alcohol at the temperature of 65 ℃, then adding azodiisobutyronitrile and a mixed monomer, and stirring for reaction for 3 hours to obtain modified magnesium hydroxide;

the primary modified magnesium hydroxide is prepared by the following steps:

mixing deionized water and absolute ethyl alcohol at 60 ℃, adding dimethoxy methyl vinyl silane, stirring for 5min, adding magnesium hydroxide, stirring for 30min, and finally evaporating the solution to obtain primary modified magnesium hydroxide;

the anti-aging additive is prepared by the following steps:

mixing N-isopropyl-N' -phenyl p-phenylenediamine and an epoxy monomer, adding salicylic acid, and reacting for 5 hours at 150 ℃ to obtain an anti-aging additive; the epoxy monomer is prepared by hydrosilylation of propenyl glycidyl ether and tetramethyl disiloxane.

2. The flame retardant rubber for a building safety net according to claim 1, wherein the mass ratio of the monomer a to the monomer b is 3:1 are mixed to form a mixed monomer.

3. The flame retardant rubber for a construction safety net according to claim 1, wherein the addition amount of azobisisobutyronitrile in step S13 is 0.4% by mass of the primary modified magnesium hydroxide, and the mass ratio of the mixed monomer to the primary modified magnesium hydroxide is 3:7.

4. the flame retardant rubber for a construction safety net according to claim 1, wherein the silane coupling agent is methyltriethoxysilane; promoter selection promoter CZ.

5. The method for preparing the flame retardant rubber for the construction safety net according to claim 1, comprising the following steps: