CN117070031B - Preparation method and application of PET prepreg with controllable temperature fusing - Google Patents

Abstract

The present invention belongs to the technical field of PET composite material preparation, _and relates to a method for preparing a PET prepreg with controllable temperature fusing and its application. The present invention comprises the following steps: _Sb2O3 and amide/amine compounds are hydrophilically modified and then mixed with latex, and then a modified graphene-based phenolic resin aqueous solution is added after being evenly dispersed, and then stirred _and mixed to obtain a functional impregnation liquid, and a two-immersion and two-rolling process is adopted to treat and strengthen the PET textile material to obtain a PET prepreg. The gradient graphene improves the thermal conductivity of the PET prepreg, and cooperates with amide/amine compounds, _Sb2O3 and latex to jointly construct a controllable temperature fusing system of a flame-retardant prepreg, so as to realize the fusing degradation of the PET prepreg at 190°C to 240°C, and solve the technical problem that the flame-retardant PET prepreg is difficult to fuse within the set temperature.

Description

Preparation method and application of PET prepreg with controllable temperature melting

Technical Field

The invention belongs to the technical field of PET composite material preparation, and in particular relates to a preparation method and application of a PET prepreg with controllable temperature fusing.

Background technique

During the operation of the conveyor, the friction between the roller and the conveyor belt will generate high temperature, which will pose a serious safety hazard to the flammable and explosive gases such as gas and methane in the mine. In order to ensure safe production, the current heavy mining industry such as coal has put forward multiple composite functional requirements for conveyor belts, such as high strength, flame retardancy, and roller friction test temperature ≤325℃ when the conveyor belt breaks.

However, the polymer rubber and latex of the conveyor belt have a large friction coefficient, high heat generation, and low thermal conductivity. The temperature gradient between the PET prepreg core layer and the rubber on the roller surface is large. The flame-retardant PET prepreg is difficult to melt within the specified temperature. This has become a common technical problem in the industry, seriously restricting the development of the high-performance laminated flame-retardant conveyor belt industry.

The key factors affecting the fusing performance of PET flame-retardant prepreg are low thermal conductivity of the prepreg coating, low heat flux from the drum surface to the PET prepreg core layer, and the actual temperature of the prepreg is much lower than the drum surface temperature; at the same time, the melting point of PET prepreg is high, and it is difficult for the prepreg to melt and break at the actual temperature. Therefore, how to provide a method for preparing PET prepreg with controllable temperature fusing and achieve the fusing of flame-retardant PET prepreg within a set temperature range is a problem that technicians in this field need to solve urgently.

Summary of the invention

In order to solve the above technical problems, the present invention proposes a preparation method and application of a PET prepreg with controllable temperature melting. The thermal conductivity system of the composite material is improved by gradient graphene, and the controllable temperature melting system of the flame-retardant prepreg is jointly constructed by amide/ _amine compounds, _Sb2O3 and latex, so as to realize the melting degradation of the PET prepreg at an actual temperature of 190°C to 240°C, thereby solving the technical problem that the flame-retardant PET prepreg is difficult to melt within the set temperature.

In one aspect, the present invention provides a method for preparing a temperature-controllable degradable PET fiber-reinforced impregnation liquid, comprising:

The temperature-controllable degradable PET fiber-reinforced impregnation liquid is obtained by mixing Sb ₂ O ₃ and amide/amine compounds with latex after being hydrophilically modified and uniformly dispersed, adding the modified graphene-based phenolic resin aqueous solution, and stirring and mixing uniformly.

Furthermore, the method for hydrophilic modification of _Sb2O3 and amide/amine compounds includes: adding _Sb2O3 or amide/amine compounds to a water-soluble polymer aqueous solution, ultrasonically dispersing for 5-10 minutes, and obtaining _{a water-soluble polymer-coated stable water-based Sb2O3 or amide /} amine compound dispersion.

Preferably, the mass concentration of the water-soluble polymer aqueous solution is 1-30%.

Preferably, the amide/amine compound is a mixture of one or more of aminotoluene, diaminodiphenyl sulfone, dibenzamide diphenyl disulfide, stearic acid phenylhydrazine, dicyandiamide, and ethylenethiourea in any proportion.

Preferably, the water-soluble polymer is one of a water-soluble polyvinyl alcohol aqueous solution, polyethylene oxide, and a methyl methacrylate copolymer.

Preferably, the mass ratio of Sb ₂ O ₃ to the water-soluble polymer is 100:(3-10).

Preferably, the particle size of the Sb ₂ O ₃ is 100 to 700 nm.

It should be noted that the amount of water-soluble polymer material added is proportional to the particle size of the Sb ₂ O ₃ material, that is, the larger the particle size of the Sb ₂ O ₃ material, the more water-soluble polymer material is added.

Preferably, the mass ratio of the amide/amine compound to the water-soluble polymer is 100:(3-7).

Furthermore, the latex is a mixture of one or more of chloroprene latex, butylpyrrolidone latex, natural latex, polysulfide latex, chlorosulfonated polyethylene latex, and polyurethane latex in any proportion.

Furthermore, the preparation method of the modified graphene-based phenolic resin aqueous solution includes: adding NaOH to the modified graphene dispersion, adding precondensed phenolic resin while stirring after magnetic dispersion, and then adding formaldehyde, reacting at 25-35° C. for 3-5 hours to obtain the modified graphene-based phenolic resin aqueous solution.

Preferably, the mass fraction of the modified graphene dispersion is 1%; the mass ratio of the modified graphene dispersion to NaOH is 48:0.1; and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

Preferably, the preparation method of the modified graphene dispersion comprises: adding graphene to water, dispersing for 15 minutes, then adding a modifier, and dispersing at 40-60° C. for 30 minutes to obtain the modified graphene dispersion.

More preferably, the mass ratio of the graphene to water is 1:99.

More preferably, the graphene is a mixture of single-layer graphene, double-layer graphene and multi-layer graphene, with a mass ratio of 1-2:1-2:1-3; the modifier is one of L-cystine, isocyanate, organic amine, silane coupling agent and titanate coupling agent; the mass ratio of the modifier to graphene is (0-2):1.

More preferably, the modifier is a titanate coupling agent.

More preferably, the titanate coupling agent is a chelated titanate coupling agent.

More preferably, the number of layers of the multilayer graphene is 5-10.

On the other hand, the present invention also provides a temperature-controllable degradable PET fiber-reinforced impregnation liquid prepared by the above method.

On the other hand, the present invention also provides an application of the above-mentioned temperature-controllable degradable PET fiber-reinforced impregnation liquid in the field of functional textiles.

On the other hand, the present invention also provides a PET prepreg with controllable temperature melting, the raw material of which includes the above-mentioned temperature-controllable degradable PET fiber-reinforced impregnation liquid.

On the other hand, the present invention also provides a method for preparing the above-mentioned temperature-controllable melting PET prepreg, comprising:

The PET canvas is pre-baked at 70°C for 30 minutes, immersed in the above-mentioned temperature-controlled degradable PET fiber reinforced impregnation liquid for 5-10 seconds, taken out and rolled evenly, pre-baked at 110°C for 10-15 minutes, cooled and immersed in the temperature-controlled degradable PET fiber reinforced impregnation liquid for 5-10 seconds again, taken out and rolled evenly again, and dried at 170°C for 5-10 minutes to obtain a PET prepreg with controllable temperature melting.

On the other hand, the present invention also provides an application of the above-mentioned temperature-controllable melting PET prepreg in the field of fabric-reinforced elastomers for flame-retardant heavy-duty conveyor belts.

It can be seen from the above technical solution that compared with the prior art, it has the following beneficial effects:

The present invention adopts gradient single-layer/double-layer/multi-layer graphene and forms an organic polar molecule coating layer on the surface of the graphene based on the modification of the graphene by a modifier. The spatial stabilization effect of the coating layer and the protection of the polar molecule associated water layer are utilized to make the graphene uniformly and stably dispersed to achieve the excellent effect of high-efficiency thermal conductivity of low-mass concentration graphene.

In the present invention _{, Sb2O3} has good phonon thermal conductivity based on the lattice vibration of the orthorhombic crystal structure, and graphene has high oxygen isolation and thermal conductivity and cooling flame retardant properties based on the regular planar hexagonal structure. The synergy of the two particles can further improve the flame retardant properties of the material.

The present invention realizes controllable temperature fusing of flame-retardant PET materials based on the synergistic use of amide/amine compounds with conjugated electrostatic effects, latex and graphene, further efficiently improves the aminolysis performance based on the formation of a stable water-based amide/amine compound dispersion liquid through water-soluble polymer coating, improves the high-temperature degradation performance of PET fibers based on the high-temperature pyrolysis catalytic reaction of latex molecules, and promotes the heat transfer efficiency of composite materials based on the efficient thermal conductivity of graphene to further improve the fusing speed of PET prepreg.

Detailed ways

Graphene, Suzhou Tanfeng Technology Co., Ltd.; precondensed phenolic resin, Anhui Huaye Special Materials Co., Ltd.; PET canvas is EE polyester fiber reinforced canvas, industrial grade, Anhui Huaye Special Materials Co., Ltd.; the purity of NaOH is analytical grade, Shanghai Lingfeng Chemical Reagent Co., Ltd.; the mass fraction of formaldehyde is 37%, Wuxi Yashenghua Co., Ltd.; chloroprene latex is anionic, Shandong Zhongyi Chemical Co., Ltd.; butylpyrrolidone latex, industrial grade, Jiangsu Yatai Chemical Co., Ltd.; L _- cystine, Jiangsu Feiqing Biotechnology Co., Ltd.; _Sb2O3 , industrial grade, Yiyang Shanxing Antimony Co., Ltd.; dibenzamide diphenyl disulfide, industrial grade, Wuhan Belleye Biotechnology Co., Ltd.; natural latex, industrial grade, Shandong Guangju Biotechnology Co., Ltd.; chlorosulfonated polyethylene latex, industrial grade, Sumitomo Corporation of Japan.

Example 1

Preparation of PET prepreg with controllable temperature melting:

S1. Add single-layer graphene, double-layer graphene and multi-layer graphene into water in a mass ratio of 1:1:2, and the mass ratio of graphene to water is 1:99, disperse for 15 minutes, then add L-cystine twice the mass of graphene, disperse at 40°C for 30 minutes, and obtain a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 35° C. for 5 hours to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add Sb ₂ O ₃ and dibenzamide diphenyl disulfide to a 5% mass concentration of polyethylene oxide aqueous solution respectively, and disperse them ultrasonically for 10 minutes to obtain a polyethylene oxide-coated stable water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyethylene oxide is 100:9, the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:7, and the particle size of Sb ₂ O ₃ is 600 nm.

S4. Mix the water- _{based Sb2O3} and dibenzamide diphenyl disulfide dispersion prepared in step S3 with chlorosulfonated polyethylene latex, add the modified graphene-based phenolic resin aqueous solution prepared in step S2 after uniform dispersion, and stir and mix to obtain a temperature-controllable and degradable PET fiber-reinforced impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S4 and immerse it for 10 s. After taking it out, roll it evenly, pre-bake it at 110°C for 15 min, cool it down, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution again and immerse it for 10 s. After taking it out, roll it evenly, and bake it at 170°C for 5 min to obtain a PET prepreg with controllable temperature melting.

Example 2

Preparation of PET prepreg with controllable temperature melting:

S1. Add single-layer graphene, double-layer graphene and multi-layer graphene into water in a mass ratio of 1:2:2, and the mass ratio of graphene to water is 1:99, disperse for 15 minutes, then add isocyanate twice the mass of graphene, disperse at 60°C for 30 minutes, and obtain a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 25°C for 3h to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add Sb ₂ O ₃ and dibenzamide diphenyl disulfide to a 5% mass concentration of polyethylene oxide aqueous solution respectively, and disperse them ultrasonically for 5 minutes to obtain a polyethylene oxide-coated stable water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyethylene oxide is 100:3, the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:3, and the particle size of Sb ₂ O ₃ is 100 nm.

S4. Mix the water- _{based Sb2O3} and dibenzamide diphenyl disulfide dispersion prepared in step S3 with chlorosulfonated polystyrene latex, and add the modified graphene-based phenolic resin aqueous solution prepared in step S2 after uniform dispersion, and stir and mix to obtain a temperature-controllable and degradable PET fiber-reinforced impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation liquid prepared in S4 and immerse it for 5 seconds. After taking it out, roll it evenly, pre-bake it at 110°C for 10 min, cool it down and put it into the temperature-controlled degradable PET fiber-reinforced impregnation liquid again and immerse it for 5 seconds. After taking it out, roll it evenly, and bake it at 170°C for 10 min to obtain a PET prepreg with controllable temperature melting.

Example 3

Preparation of PET prepreg with controllable temperature melting:

S1. Add single-layer graphene, double-layer graphene and multi-layer graphene into water in a mass ratio of 1:1:3, the mass ratio of graphene to water is 1:99, disperse for 15 minutes, then add isocyanate twice the mass of graphene, disperse at 60°C for 30 minutes to obtain a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 30° C. for 4 hours to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add Sb ₂ O ₃ and dibenzamide diphenyl disulfide to a 5% mass concentration of polyethylene oxide aqueous solution respectively, and disperse them ultrasonically for 7 minutes to obtain a polyethylene oxide-coated stable water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyethylene oxide is 100:5, the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:7, and the particle size of Sb ₂ O ₃ is 400 nm.

S4. Mix the water- _{based Sb2O3} and dibenzamide diphenyl disulfide dispersion prepared in step S3 with chlorosulfonated polyethylene latex, add the modified graphene-based phenolic resin aqueous solution prepared in step S2 after uniform dispersion, and stir and mix to obtain a temperature-controllable and degradable PET fiber-reinforced impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S4 and immerse it for 7 seconds. After taking it out, roll it evenly, pre-bake it at 110°C for 12 min, cool it down, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution again and immerse it for 8 seconds. After taking it out, roll it evenly, and bake it at 170°C for 8 min to obtain a PET prepreg with controllable temperature melting.

Comparative Example 1

Compared with Example 1, the only difference is that Sb ₂ O ₃ is not added in the preparation method of the impregnation solution. The specific preparation method is as follows:

S1. Add single-layer graphene, double-layer graphene and multi-layer graphene into water in a mass ratio of 1:1:2, and the mass ratio of graphene to water is 1:99, disperse for 15 minutes, then add L-cystine twice the mass of graphene, disperse at 60°C for 30 minutes, and obtain a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 35° C. for 5 hours to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add dibenzamide diphenyl disulfide to a 5% aqueous solution of polyethylene oxide, and disperse it by ultrasonic for 10 minutes to obtain a stable aqueous dispersion of dibenzamide diphenyl disulfide coated with polyethylene oxide, wherein the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:7.

S4, mixing the water-based dibenzamide diphenyl disulfide dispersion prepared in step S3 with chlorosulfonated polyethylene latex, and adding the modified graphene-based phenolic resin aqueous solution prepared in step S2 after uniform dispersion, stirring and mixing to obtain a PET fiber reinforced impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S4 and immerse it for 10 s. After taking it out, roll it evenly, pre-bake it at 110°C for 15 min, cool it down and immerse it in the temperature-controlled degradable PET fiber-reinforced impregnation solution again for 10 s. After taking it out, roll it evenly, and dry it at 170°C for 5 min to obtain the PET prepreg.

Comparative Example 2

Compared with Example 1, the only difference is that in the preparation method of the impregnation solution, dibenzamide diphenyl disulfide is not added. The specific preparation method is as follows:

S1. Add single-layer graphene, double-layer graphene and multi-layer graphene into water in a mass ratio of 1:1:2, and the mass ratio of graphene to water is 1:99, disperse for 15 minutes, then add L-cystine twice the mass of graphene, disperse at 60°C for 30 minutes, and obtain a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 35° C. for 5 hours to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add Sb ₂ O ₃ into a 5% polyoxyethylene aqueous solution and disperse it by ultrasonic for 10 minutes to obtain a polyoxyethylene-coated stable water-based Sb ₂ O ₃ dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyoxyethylene is 100:9 and the particle size of Sb ₂ O ₃ is 600 nm.

S4, mixing the water-based Sb ₂ O ₃ dispersion prepared in step S3 with chlorosulfonated polyethylene latex, adding the modified graphene-based phenolic resin aqueous solution prepared in step S2 after uniform dispersion, stirring and mixing to obtain a PET fiber-reinforced impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S4 and immerse it for 10 s. After taking it out, roll it evenly, pre-bake it at 110°C for 15 min, cool it down and immerse it in the temperature-controlled degradable PET fiber-reinforced impregnation solution again for 10 s. After taking it out, roll it evenly, and dry it at 170°C for 5 min to obtain the PET prepreg.

Comparative Example 3

Compared with Example 1, the only difference is that graphene is not added in the preparation method of the impregnation solution. The specific preparation method is as follows:

S1. Add NaOH to the pre-condensed phenolic resin, add formaldehyde while stirring, and react at 35°C for 5 hours to obtain a phenolic resin aqueous solution.

S2. Add Sb ₂ O ₃ and dibenzamide diphenyl disulfide to a 5% mass concentration of polyethylene oxide aqueous solution respectively, and disperse them ultrasonically for 10 minutes to obtain a polyethylene oxide-coated stable water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyethylene oxide is 100:9, the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:7, and the particle size of Sb ₂ O ₃ is 600 nm.

S3, mixing the water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion prepared in step S2 with chlorosulfonated polyethylene latex, adding the phenolic resin aqueous solution prepared in step S1 after uniform dispersion, stirring and mixing to obtain PET fiber reinforcement impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S4 and immerse it for 10 s. After taking it out, roll it evenly, pre-bake it at 110°C for 15 min, cool it down and immerse it in the temperature-controlled degradable PET fiber-reinforced impregnation solution again for 10 s. After taking it out, roll it evenly, and dry it at 170°C for 5 min to obtain the PET prepreg.

Comparative Example 4

Compared with Example 1, the only difference is that in the preparation method of the impregnation solution, the added graphene is a single-layer graphene, and the specific preparation method is as follows:

S1. Adding a single layer of graphene into water with a mass ratio of graphene to water of 1:99, dispersing for 15 minutes, then adding L-cystine twice the mass of the graphene, dispersing at 60° C. for 30 minutes, and obtaining a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 35° C. for 5 hours to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add Sb ₂ O ₃ and dibenzamide diphenyl disulfide to a 5% mass concentration of polyethylene oxide aqueous solution respectively, and disperse them ultrasonically for 10 minutes to obtain a polyethylene oxide-coated stable water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyethylene oxide is 100:9, the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:7, and the particle size of Sb ₂ O ₃ is 600 nm.

S4, mixing the water-based _Sb2O3 and dibenzamide diphenyl disulfide dispersion prepared in step S3 with chlorosulfonated polyethylene latex, adding the modified graphene-based phenolic resin aqueous solution prepared in step S2 _after uniform dispersion, stirring and mixing to obtain a PET fiber reinforced impregnation solution.

S5, pre-dry the PET canvas at 70°C for 30 minutes, put it into the temperature-controlled degradable PET fiber-reinforced impregnation liquid prepared in S4 and immerse it for 10 seconds, take it out and roll it evenly, then pre-dry it at 110°C for 15 minutes, cool it down and put it into the temperature-controlled degradable PET fiber-reinforced impregnation liquid again and immerse it for 10 seconds, take it out and roll it evenly, and dry it at 170°C for 5 minutes to obtain the PET prepreg

Comparative Example 5

Compared with Example 1, the only difference is that in the preparation method of the impregnation solution, the added graphene is double-layer graphene, and the specific preparation method is as follows:

S1. Add double-layer graphene to water with a mass ratio of graphene to water of 1:99, disperse for 15 minutes, then add L-cystine twice the mass of graphene, disperse at 60° C. for 30 minutes to obtain a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 35° C. for 5 hours to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add Sb ₂ O ₃ and dibenzamide diphenyl disulfide to a 5% mass concentration of polyethylene oxide aqueous solution respectively, and disperse them ultrasonically for 10 minutes to obtain a polyethylene oxide-coated stable water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyethylene oxide is 100:9, the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:7, and the particle size of Sb ₂ O ₃ is 600 nm.

S4, mixing the water-based _Sb2O3 and dibenzamide diphenyl disulfide dispersion prepared in step S3 with chlorosulfonated polyethylene latex, adding the modified graphene-based phenolic resin aqueous solution prepared in step S2 _after uniform dispersion, stirring and mixing to obtain a PET fiber reinforced impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S4 and immerse it for 10 s. After taking it out, roll it evenly, pre-bake it at 110°C for 15 min, cool it down and immerse it in the temperature-controlled degradable PET fiber-reinforced impregnation solution again for 10 s. After taking it out, roll it evenly, and dry it at 170°C for 5 min to obtain the PET prepreg.

Comparative Example 6

Compared with Example 1, the only difference is that in the preparation method of the impregnation solution, the added graphene is multilayer graphene, and the specific preparation method is as follows:

S1. Add multilayer graphene into water with a mass ratio of graphene to water of 1:99, disperse for 15 minutes, then add L-cystine twice the mass of graphene, disperse at 60° C. for 30 minutes to obtain a modified graphene dispersion.

S2. Add NaOH to the modified graphene dispersion prepared in step S1, add precondensed phenolic resin while stirring after magnetic dispersion, and then add formaldehyde, and react at 35° C. for 5 hours to obtain a modified graphene-based phenolic resin aqueous solution, wherein the mass ratio of the modified graphene dispersion to NaOH is 48:0.1, and the mass ratio of NaOH, precondensed phenolic resin and formaldehyde is 1:62:18.

S3. Add Sb ₂ O ₃ and dibenzamide diphenyl disulfide to a 5% mass concentration of polyethylene oxide aqueous solution respectively, and disperse them ultrasonically for 10 minutes to obtain a polyethylene oxide-coated stable water-based Sb ₂ O ₃ and dibenzamide diphenyl disulfide dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyethylene oxide is 100:9, the mass ratio of dibenzamide diphenyl disulfide to polyethylene oxide is 100:7, and the particle size of Sb ₂ O ₃ is 600 nm.

S4, mixing the water-based _Sb2O3 and dibenzamide diphenyl disulfide dispersion prepared in step S3 with chlorosulfonated polyethylene latex, adding the modified graphene-based phenolic resin aqueous solution prepared in step S2 _after uniform dispersion, stirring and mixing to obtain a PET fiber reinforced impregnation solution.

S5. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S4 and immerse it for 10 s. After taking it out, roll it evenly, pre-bake it at 110°C for 15 min, cool it down and immerse it in the temperature-controlled degradable PET fiber-reinforced impregnation solution again for 10 s. After taking it out, roll it evenly, and dry it at 170°C for 5 min to obtain the PET prepreg.

Comparative Example 7

Preparation of PET composite fabric:

S1. Add NaOH to the pre-condensed phenolic resin, add formaldehyde while stirring, and react at 35°C for 5 hours to obtain a phenolic resin aqueous solution.

S2. Add Sb ₂ O ₃ into a 5% polyoxyethylene aqueous solution and disperse it by ultrasonic for 10 minutes to obtain a polyoxyethylene-coated stable water-based Sb ₂ O ₃ dispersion, wherein the mass ratio of Sb ₂ O ₃ to polyoxyethylene is 100:9 and the particle size of Sb ₂ O ₃ is 600 nm.

S3, the water-based Sb ₂ O ₃ prepared in step S3 is mixed with chloroprene/natural/butylpyrrolidone latex, dispersed evenly, and then added with the phenolic resin aqueous solution prepared in step S1, stirred and mixed evenly to obtain the PET fiber reinforcement impregnation solution.

S4. Pre-bake the PET canvas at 70°C for 30 min, put it into the temperature-controlled degradable PET fiber-reinforced impregnation solution prepared in S3 and immerse it for 10 s. After taking it out, roll it evenly, pre-bake it at 110°C for 15 min, cool it down and immerse it in the temperature-controlled degradable PET fiber-reinforced impregnation solution again for 10 s. After taking it out, roll it evenly, and dry it at 170°C for 5 min to obtain the PET prepreg.

Test example

1. Fuse performance test and aging performance test

Fusing temperature test method:

According to a conventional method, the PET prepreg prepared by the present invention is used to prepare a rubber layered conveyor belt; according to Appendix E Roller Friction Test Method for Mineral Fabric Core Flame-retardant Conveyor Belt (MT/T 914-2019), a sample is prepared and tested. When the conveyor belt sample is worn off, an inserted thermocouple is used to measure the temperature of the composite fabric. The test results are shown in Table 1.

Thermal sample aging performance test method:

According to the conventional method, the PET prepreg prepared by the present invention is placed in an aging test box and thermally aged for 30 minutes at 220°C. The strength loss rate of the sample after thermal oxidative aging is calculated by comparing with the unaged sample test. The test results are shown in Table 1.

Table 1

It can be seen from the data of Example 1 and Comparative Examples 3-6 in Table 1 that the performance of the compounded gradient graphene in Example 1 is the best, and the melting temperature of the multilayer graphene is the lowest when single-layer, double-layer and multi-layer graphene are used alone. It can be seen that the melting performance of the final product can be improved by compounding gradient graphene.

Meanwhile, by comparing the data of Example 1 with Comparative Examples 1 and 2, when no Sb ₂ O ₃ or amine/amide compounds are added, the performance parameters of the product without adding amine/amide compounds are greatly different from those of Example 1.

2. Thermal conductivity test

Method: Prepare and test the sample according to the "Test Method for Thermal Conductivity of Dipped Canvas (GB/T 41958-2022)". The experimental temperature is 50°C and the sample size is 50×50mm. The comprehensive thermal conductivity of the test is shown in Table 2:

Table 2

It can be seen from the data of Example 1 and Comparative Examples 3-6 in Table 2 that the thermal conductivity of the compounded gradient graphene in Example 1 is the best, and the thermal conductivity of the multilayer graphene is the highest when single-layer, double-layer, and multi-layer graphene are used alone. It can be seen that the thermal conductivity of the final product can be improved by compounding gradient graphene, thereby promoting the realization of controllable temperature fusing.

At the same time, when the data of Example 1 is compared with those of Comparative Examples 1 and 2, the performance parameters of the product without adding Sb ₂ O ₃ are significantly different from _those of Example 1 _.

3. Flame retardant performance test

Test method: According to the conventional method, the PET prepreg prepared by the present invention is used to prepare a rubber layered conveyor belt; according to Appendix F alcohol burner combustion test method (MT/T914-2019) of mineral fabric core flame retardant conveyor belt, a sample is prepared and tested, and the sample with the covering layer peeled off is tested. The test results are shown in Table 3.

table 3

It can be seen from the data of Comparative Example 1 that when Sb ₂ O ₃ is reduced in the raw material, the flaming combustion time can be significantly affected, but the flameless combustion time has little effect.

4. Mechanical properties test

Mechanical properties test

Each sample was tested using a YG026Q electronic fabric strength tester produced by Shanghai Shuangxu Electronics Co., Ltd. The test standard is GB/T3923.1-201, test temperature: 20°C, test humidity: 65% RH, force unit: N, pre-tension: 2, clamping distance: 100mm, moving speed: 100mm/min, fixed-point force: 2000N, fixed-point elongation: 150%.

The tensile strength and tensile elongation at break of Examples 1-3 and Comparative Examples 1-7 were tested, with PET canvas material as a control group (CK). The results are shown in Table 4.

Table 4

Since the thermal processing process will affect the strength of PET fiber, it can be seen from the data in Table 4 that although the tensile strength and tensile elongation at break of the embodiment of the present invention are reduced compared with the strength of the control group (CK), the strength loss is controlled within 5%.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. The preparation method of the temperature-controllable degradable PET fiber reinforced impregnating solution is characterized by comprising the following steps of:

Mixing Sb ₂O₃ and amide/amine compounds with chlorosulfonated polyethylene latex after hydrophilic modification, adding modified graphene-based phenolic resin aqueous solution after uniform dispersion, and stirring and uniformly mixing to obtain the temperature-controllable degradable PET fiber reinforced impregnating solution;

the method for hydrophilic modification of the Sb ₂O₃ and the amide/amine compounds comprises the following steps:

Adding Sb ₂O₃ or amide/amine compounds into a water-soluble polymer aqueous solution, and performing ultrasonic dispersion for 5-10min to obtain a water-soluble polymer coated stable water-based Sb ₂O₃ or amide/amine compound dispersion;

the water-soluble polymer is polyoxyethylene;

The amide/amine compound is dibenzoyl amino diphenyl disulfide;

The preparation method of the modified graphene-based phenolic resin aqueous solution comprises the following steps:

Adding NaOH into the modified graphene dispersion liquid, stirring the mixture while adding pre-condensed phenolic resin after magnetic dispersion, adding formaldehyde, and reacting at 25-35 ℃ for 3-5 hours to obtain modified graphene phenolic resin aqueous solution;

The preparation method of the modified graphene dispersion liquid comprises the following steps:

Adding graphene into water, dispersing for 15min, then adding a modifier, and dispersing at 60 ℃ for 30min to obtain modified graphene dispersion liquid;

The graphene is a mixture of single-layer graphene, double-layer graphene and multi-layer graphene, and the mass is 1-2:1-2:1-3;

the modifier is L-cystine or isocyanate.

2. The preparation method according to claim 1, wherein the mass concentration of the water-soluble polymer aqueous solution is 1-30%.

3. The preparation method according to claim 1, wherein the mass fraction of the modified graphene dispersion is 1%; the mass ratio of the modified graphene dispersion liquid to NaOH is 48:0.1; the mass ratio of NaOH to pre-condensed phenolic resin to formaldehyde is 1:62:18.

4. The preparation method according to claim 1, wherein the mass ratio of graphene to water is 1:99; the mass ratio of the modifier to the graphene is 0-2:1; the number of the lamellar layers of the multilayer graphene is 5-10.

5. A temperature-controllable degradable PET fiber reinforced impregnating solution prepared by the preparation method according to any one of claims 1 to 4.

6. Use of a temperature-controllable degradable PET fiber-reinforced impregnation fluid according to claim 5 in the field of functional textiles.

7. A temperature-controllable fused PET prepreg, characterized in that the raw material comprises the temperature-controllable degradable PET fiber reinforced impregnating solution according to claim 5.

8. A method of preparing a temperature-controlled melt PET prepreg according to claim 7, comprising the steps of:

Pre-baking the PET material at 70 ℃ for 30min, immersing the PET material in the temperature-controllable degradable PET fiber reinforced impregnating solution for 5-10s, taking out, rolling and pressing uniformly by a roller, pre-baking for 10-15min at 110 ℃, cooling, immersing the PET material in the temperature-controllable degradable PET fiber reinforced impregnating solution for 5-10s again, taking out, rolling and pressing uniformly by a roller again, and drying for 5-10min at 170 ℃ to obtain the temperature-controllable fused PET prepreg.

9. Use of a temperature-controllable, fused PET prepreg according to claim 7 in the field of textile-reinforced elastomers for flame-retardant heavy-duty conveyor belts.