阅读说明：本技术 一种耐高温蜂窝芯材用聚对苯撑苯并二噁唑纤维纸基材料及其制备方法 (Poly (p-phenylene benzobisoxazole) fiber paper base material for high-temperature-resistant honeycomb core material and preparation method thereof ) 是由 王玉阳 王志新 江明 刘萍 郭丽丽 叶小雯 于 2020-12-25 设计创作，主要内容包括：本发明公开了一种耐高温蜂窝芯材用聚对苯撑苯并二噁唑纤维纸基材料及其制备方法,具体包括以下步骤：将PBO短切纤维做预处理；把预处理后的PBO纤维与间位芳纶短切纤维共同分散,并与分散好的间位芳纶沉析纤维混合抄造；采用湿法成型,经压榨、干燥、得到PBO纤维纸原纸,再经高温压光整饰得到耐高温蜂窝材料用聚对苯撑苯并二噁唑纤维纸基材料。本发明所提供的聚对苯撑苯并二噁唑纤维纸基材料制备方法,利用PBO纤维超高强度、超高模量以及优异的耐高温、阻燃性能,采用混杂纤维复合抄造工艺制备出耐温性能、阻燃性能、机械强度优异的纸基材料,满足航空航天用蜂窝材料对聚对苯撑苯并二噁唑纤维纸基材料的性能需求。(The invention discloses a poly (p-phenylene benzobisoxazole) fiber paper base material for a high-temperature-resistant honeycomb core material and a preparation method thereof, and the preparation method specifically comprises the following steps: pretreating PBO chopped fibers; the pretreated PBO fiber and the meta-aramid chopped fiber are dispersed together and mixed with the dispersed meta-aramid fibrid for papermaking; the base material of the poly-p-phenylene benzobisoxazole fiber paper for the high-temperature resistant honeycomb material is obtained by wet forming, squeezing and drying to obtain base paper of PBO fiber paper and then performing high-temperature press finishing. According to the preparation method of the poly (p-phenylene benzobisoxazole) fiber paper base material, the PBO fiber is used for preparing the paper base material with excellent temperature resistance, flame resistance and mechanical strength by utilizing the ultrahigh strength, ultrahigh modulus and excellent high temperature resistance and flame resistance, and the hybrid fiber composite papermaking process is adopted, so that the performance requirements of the honeycomb material for aerospace on the poly (p-phenylene benzobisoxazole) fiber paper base material are met.)

1. The utility model provides a high temperature resistant honeycomb core is with poly p phenylene benzo dioxazole fiber paper base material which characterized in that, is made by the mixing of three kinds of components of PBO chopped strand, meta-position aramid fiber settling out fiber, and by the mass fraction, its ratio is as follows: the mass ratio of the PBO chopped fibers is 30-80%, the mass ratio of the meta-aramid chopped fibers is 0-30%, the mass ratio of the meta-aramid fibrids is 20-50%, and the sum of the mass fractions of the components is 100%.

2. The preparation method of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material as claimed in claim 1, which is characterized by comprising the following steps:

the method comprises the following steps: immersing absolutely dry PBO chopped fibers into alkali liquor for pretreatment, then washing the pretreated PBO chopped fibers to be neutral by using deionized water, and drying for later use;

step two: mixing absolutely dry meta-aramid chopped fibers with the PBO chopped fibers treated in the first step, and adding a dispersing agent to carry out first defibering and dispersing; adding meta-aramid fibrid to carry out secondary defibering and dispersing, adding water to adjust the concentration of the paper pulp, and carrying out tertiary defibering and dispersing to prepare mixed slurry;

step three: dehydrating and forming the defibered mixed slurry obtained in the second step to obtain wet mixed papermaking sheets, and then squeezing and drying to obtain base paper of the PBO fiber paper base material;

step four: and (4) performing high-temperature press polishing treatment on the base paper of the PBO fiber paper base material prepared in the step three to obtain the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature-resistant honeycomb core material.

3. The method for preparing the poly-p-phenylene benzobisoxazole fiber paper base material for the high temperature resistant honeycomb core material as claimed in claim 2, wherein the length of the PBO chopped fiber in the first step is 3-8 mm.

4. The method for preparing the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material as claimed in claim 2, wherein the alkali liquor in the first step is sodium hydroxide solution with the mass fraction of 1% -5%.

5. The method for preparing the poly-p-phenylene benzobisoxazole fiber paper base material for the high temperature resistant honeycomb core material as claimed in claim 2, characterized in that in the second step, water is added to adjust the mass concentration of the slurry to 0.01% -0.05%.

6. The method for preparing the poly-p-phenylene benzobisoxazole fiber paper base material for the high temperature resistant honeycomb core material as claimed in claim 2, characterized in that the dispersant in the second step is one or more of polyacrylamide, polymethacrylic acid, polyvinyl alcohol, polyethylene oxide and polyvinylpyrrolidone; the dosage of the dispersant is 0.3-1.0 percent of the oven dry mass sum of the PBO chopped fiber and the meta-aramid chopped fiber.

7. The method for preparing the poly (p-phenylene benzobisoxazole) fiber paper base material for the high-temperature resistant honeycomb core material as claimed in claim 2, wherein the drying temperature in the third step is 80-120 ℃.

8. The preparation method of the poly (p-phenylene benzobisoxazole) fiber paper base material for the high-temperature-resistant honeycomb core material as claimed in claim 2, wherein the high-temperature calendering conditions in the four steps are as follows: the calendering temperature is 220-320 ℃, the calendering line pressure is 80-160N/mm, the calendering roller rotating speed is 3-9m/min, and the calendering frequency is 1-3.

Technical Field

The invention relates to the technical field of high-temperature-resistant special paper, in particular to a poly (p-phenylene benzobisoxazole) fiber paper base material for a high-temperature-resistant honeycomb core material and a preparation method thereof.

Background

Poly (p-phenylene benzobisoxazole) (PBO fiber) is a polyamide group high polymer fiber containing heterocyclic aromatic, and was originally developed by the american air force materials laboratory as a material having better high temperature resistance than Kevlar (Kevlar). Firstly, the PBO fiber has excellent heat resistance, the thermal decomposition temperature of the PBO fiber is above 650 ℃, the PBO fiber is about 100 ℃ higher than the para-aramid fiber, and the PBO fiber is the fiber with the best heat resistance in organic synthetic fibers; and the flame retardant property of the PBO fiber is excellent: the Limiting Oxygen Index (LOI) of the PBO textile IS 68, the combustion performance of the PBO textile IS tested by using a J IS vertical method, the carbonization length of the PBO textile IS less than 5mm, and only a very small amount of toxic gases such as carbon monoxide, hydrogen cyanide and the like volatilize in the combustion process; in addition, the PBO fiber has excellent chemical medium resistance, is stable in almost all organic solvents and alkalis, and can be dissolved only by concentrated sulfuric acid, methanesulfonic acid, chlorosulfonic acid and other partial strong acids. In addition, the PBO fiber has good stability to hypochlorous acid, and the PBO fiber can still maintain the strength of more than 90 percent after being soaked in a bleaching agent for 300 hours. The PBO fiber also has the excellent performances of ultrahigh strength, ultrahigh modulus, good dimensional stability and the like. The high modulus PBO fiber has linear density of 1.7D, tensile strength of 5.8GPa and tensile modulus up to 352 Gpa. For dimensional stability, the PBO fiber is subjected to no-load heat treatment for 30min at the temperature of 300 ℃, and the shrinkage rate is only 0.1%. Due to the advantages, the PBO fiber is widely applied to the fields of mechanical industry, chemical industry, military and national defense, safety protection, electronic and electric appliances, building materials, aerospace and the like.

PBO fibers in the current market are mostly used for fabrics or used as reinforcing agents to prepare composite materials (patent CN111534048A discloses a preparation method of a thermosetting resin PBO fiber composite material, which is to coat sizing agents on the surface of PBO fiber fabrics and then bond the PBO fiber fabrics with thermosetting resins to prepare the composite material; patent CN111484740A discloses a blending material which adopts polyphenyl ester and PBO fibers to fill thermoplastic resins and a preparation method thereof, and the composite material with good wear resistance is prepared by compounding and blending the thermoplastic polymer resins, the polyphenyl ester resins, the PBO fibers, reinforcing fibers and lubricating auxiliary materials). However, the PBO fiber has the problems of high crystallinity and strong inertia of the fiber surface, and when the PBO fiber is combined with resin, sizing agent and binder, the prepared composite material is easy to crack, delaminate and the like under high temperature conditions due to weak interface binding force and poor high temperature resistance of the additive, so that the service life of a structural member is seriously shortened.

Disclosure of Invention

The invention aims to provide a poly (p-phenylene benzobisoxazole) fiber paper base material for a high-temperature-resistant honeycomb core material and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a high temperature resistant honeycomb core is with poly p phenylene benzo dioxazole fiber paper base material, is made by the mixing of PBO chopped fiber, meta-position aramid fiber chopped fiber, three kinds of components of meta-position aramid fiber fibrid, by the mass fraction, its ratio as follows: the mass ratio of the PBO chopped fibers is 30-80%, the mass ratio of the meta-aramid chopped fibers is 0-30%, the mass ratio of the meta-aramid fibrids is 20-50%, and the sum of the mass fractions of the components is 100%.

A preparation method of a poly (p-phenylene benzobisoxazole) fiber paper base material for a high-temperature-resistant honeycomb core material comprises the following steps:

the method comprises the following steps: immersing absolutely dry PBO chopped fibers into alkali liquor for pretreatment, then washing the pretreated PBO chopped fibers to be neutral by using deionized water, and drying for later use;

step two: mixing absolutely dry meta-aramid chopped fibers with the PBO chopped fibers treated in the first step, and adding a dispersing agent to carry out first defibering and dispersing; adding meta-aramid fibrid to carry out secondary defibering and dispersing, adding water to adjust the concentration of the paper pulp, and carrying out tertiary defibering and dispersing to prepare mixed slurry;

step three: dehydrating and forming the defibered mixed slurry obtained in the second step to obtain wet mixed papermaking sheets, and then squeezing and drying to obtain base paper of the PBO fiber paper base material;

step four: and (4) performing high-temperature press polishing treatment on the base paper of the PBO fiber paper base material prepared in the step three to obtain the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature-resistant honeycomb core material.

Further, the length of the PBO chopped fiber in the step one is 3-8 mm.

Further, in the step one, the alkali liquor is a sodium hydroxide solution with the mass fraction of 1% -5%.

Further, water is added in the second step to adjust the mass concentration of the slurry to 0.01-0.05%.

Further, in the second step, the dispersant is one or a mixture of more of polyacrylamide, polymethacrylic acid, polyvinyl alcohol, polyethylene oxide and polyvinylpyrrolidone; the dosage of the dispersant is 0.3-1.0 percent of the oven dry mass sum of the PBO chopped fiber and the meta-aramid chopped fiber.

Further, the drying temperature in the third step is 80-120 ℃.

Further, the high-temperature calendering conditions in the fourth step are as follows: the calendering temperature is 220-320 ℃, the calendering line pressure is 80-160N/mm, the calendering roller rotating speed is 3-9m/min, and the calendering frequency is 1-3.

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

the invention utilizes the excellent mechanical property and high temperature resistance of PBO fiber to prepare the poly-p-phenylene benzobisoxazole fiber paper base material for the high temperature resistant honeycomb core material. The PBO chopped fibers and the meta-aramid chopped fibers are used as frameworks, the fibrids are used as binders, and the high-temperature resistance of the paper-based material is improved through alternate lapping and forming, so that the mechanical property of the paper-based material is also obviously improved. The raw paper of the paper base material of the PBO fiber is prepared by adopting the modern wet forming technology, the fiber pretreatment process improves the dispersion effect of the PBO chopped fibers and ensures that the PBO chopped fibers are uniformly dispersed in the paper base material, thereby improving the mechanical strength of the paper base material and improving the stability of the performance of the paper base material; and then the PBO fiber paper base material is successfully prepared by a high-temperature calendaring process. Compared with the conventional preparation method of the PBO composite material, the preparation method of the PBO fiber paper base material provided by the invention takes the PBO chopped fibers and the meta-aramid chopped fibers as the framework and the fibrids as the binder, and the two materials are tightly combined. In the preparation process of the paper base material, other chemical adhesive auxiliary agents are not required to be added additionally, so that the paper base material is more environment-friendly, and meanwhile, the damage of the chemical adhesive auxiliary agents to the comprehensive performance of the paper base material is avoided, and the product has better mechanical property and temperature resistance and high temperature performance.

Drawings

FIG. 1 is a process flow diagram of the preparation method of the present invention.

Detailed Description

The invention is described in further detail below:

the PBO fiber and aramid fibrid are processed by a modern wet papermaking technology and a high-temperature calendering process to prepare the poly-p-phenylene benzobisoxazole fiber paper base material with high mechanical strength and good high-temperature resistance. The successful development of the paper-based material provides an important high-temperature resistant material for the military industry field and the aerospace field.

The poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material is prepared by mixing and papermaking three components, namely PBO chopped fiber, meta-position aramid chopped fiber and meta-position aramid fibrid, and the mixture ratio is as follows: the mass ratio of the PBO chopped fibers is 30-80%, the mass ratio of the meta-aramid chopped fibers is 0-30%, the mass ratio of the meta-aramid fibrids is 20-50%, and the sum of the mass fractions of the components is 100%.

A preparation method of a poly (p-phenylene-benzobisoxazole) fiber paper base material for a high-temperature-resistant honeycomb core material comprises the following steps:

firstly, soaking oven-dried PBO chopped fibers with the length of 3-8mm into a sodium hydroxide solution with the mass fraction of 1% -5% for pretreatment, then washing the pretreated PBO chopped fibers to be neutral by using deionized water, and drying for later use;

secondly, taking absolutely dry meta-aramid chopped fibers and the PBO chopped fibers treated in the first step together, putting the absolutely dry meta-aramid chopped fibers and the PBO chopped fibers treated in the first step into a fluffer, adding a dispersant according to a certain proportion, and then carrying out primary fluffing dispersion, wherein the dispersant is one of polyacrylamide, polymethacrylic acid, polyvinyl alcohol, polyethylene oxide and polyvinylpyrrolidone; the addition amount of the dispersant is 0.3-1.0% of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; adding meta-aramid fibrid into the pulp to carry out secondary defibering and dispersing, adding water to adjust the mass concentration of the pulp to 0.01-0.05%, and carrying out tertiary defibering and dispersing to prepare mixed pulp;

step three, dehydrating and forming the defibered mixed slurry in the step two in a paper industry former with 200 meshes to obtain a wet mixed paper sheet, and then squeezing and drying (the drying temperature is 80-120 ℃) to obtain raw paper of the PBO fiber paper-based material;

and step four, performing high-temperature calendering treatment on the base paper of the PBO fiber paper-based material prepared in the step three, wherein the calendering temperature is 220-320 ℃, the calendering line pressure is 80-160N/mm, the calendering roller rotating speed is 3-9m/min, and the calendering times are 1-3 times, so as to obtain the poly (p-phenylene benzobisoxazole) fiber paper-based material for the high-temperature-resistant honeycomb core material.

The present invention will be described in more detail with reference to examples. It is to be understood that the practice of the invention is not limited to the following examples, and that any variations and/or modifications may be made thereto without departing from the scope of the invention.

In the present invention, all the devices and materials are commercially available or commonly used in the industry, if not specifically mentioned. The methods in the following examples are conventional in the art unless otherwise specified.

Example 1

And (2) immersing oven-dried PBO chopped fibers with the length of 3mm into a NaOH solution with the mass fraction of 1% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r according to the mass ratio of 3:1, adding polyoxyethylene serving as a dispersing agent during fluffing, wherein the addition amount is 0.3 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; finally, adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 3:1:6 for second defibering and dispersing by 10000r, adding water to adjust the mass concentration of paper pulp to 0.01%, and defibering and dispersing by 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a paper industry former with 200 meshes to obtain wet paper sheets of mixed paper, and then squeezing and drying at 80 ℃ to obtain raw paper of the PBO fiber paper-based material; and (3) performing calendaring on the prepared base paper of the PBO fiber paper base material for 2 times at a calendaring temperature of 220 ℃, a calendaring line pressure of 80N/mm and a calendaring roller speed of 5m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 2

The method comprises the steps of immersing oven-dried PBO chopped fibers with the length of 8mm into a NaOH solution with the mass fraction of 5% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer at the same time according to the mass ratio of 8:0 for fluffing and dispersing by 10000r, adding polyoxyethylene serving as a dispersing agent during fluffing, wherein the addition amount is 1.0 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; finally, adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 8:0:2 to carry out secondary defibering and dispersing of 10000r, adding water to adjust the mass concentration of paper pulp to 0.05%, and defibering and dispersing of 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a paper industry former with 200 meshes to obtain wet paper sheets of mixed paper, and then squeezing and drying at 120 ℃ to obtain raw paper of the PBO fiber paper-based material; and performing calendaring on the prepared base paper of the PBO fiber paper base material for 1 time at the calendaring temperature of 320 ℃, the calendaring line pressure of 120N/mm and the calendaring roller speed of 9m/min by using a high-temperature calendaring machine to obtain the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 3

And (2) immersing oven-dried PBO chopped fibers with the length of 5mm into a NaOH solution with the mass fraction of 3% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r according to the mass ratio of 7:0, adding polyoxyethylene serving as a dispersing agent during fluffing, wherein the addition amount is 0.7 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; finally, adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 7:0:3 for second defibering and dispersing by 10000r, adding water to adjust the mass concentration of paper pulp to 0.03%, and defibering and dispersing by 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a paper industry former with 200 meshes to obtain wet paper sheets of mixed paper, and then squeezing and drying at 100 ℃ to obtain raw paper of the PBO fiber paper base material; and performing calendaring on the prepared base paper of the PBO fiber paper base material for 3 times at a calendaring temperature of 280 ℃, a calendaring line pressure of 110N/mm and a calendaring roller speed of 3m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 4

The method comprises the steps of immersing oven-dried PBO chopped fibers with the length of 4mm into a NaOH solution with the mass fraction of 2% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r at the same time according to the mass ratio of 1:1, adding polyacrylamide as a dispersing agent during fluffing, wherein the addition amount is 0.4 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; finally, adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 3:3:4 to carry out secondary defibering and dispersing of 10000r, adding water to adjust the concentration of paper pulp to 0.02%, and defibering and dispersing of 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a paper industry former with 200 meshes to obtain wet paper sheets of mixed paper, and then squeezing and drying at 110 ℃ to obtain raw paper of the PBO fiber paper base material; and performing calendaring on the prepared base paper of the PBO fiber paper base material for 3 times at a calendaring temperature of 280 ℃, a calendaring line pressure of 160N/mm and a calendaring roller speed of 7m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 5

The method comprises the steps of immersing oven-dried PBO chopped fibers with the length of 6mm into a NaOH solution with the mass fraction of 2% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r according to the mass ratio of 5:3, adding polyoxyethylene serving as a dispersing agent during fluffing, wherein the addition amount is 0.8 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; then adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 5:3:2 to carry out secondary defibering and dispersing of 10000r, adding water to adjust the mass concentration of paper pulp to 0.02%, and defibering and dispersing of 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a 200-mesh paper industry former to obtain wet paper sheets of mixed paper, and then squeezing and drying at 90 ℃ to obtain raw paper of the PBO fiber paper-based material; and (3) performing calendaring on the prepared base paper of the PBO fiber paper base material for 1 time at a calendaring temperature of 250 ℃, a calendaring line pressure of 100N/mm and a calendaring roller speed of 8m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 6

And (2) immersing the oven-dried PBO chopped fibers with the length of 7mm into a NaOH solution with the mass fraction of 4% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r according to the mass ratio of 3:1, adding polyacrylamide as a dispersing agent during fluffing, wherein the addition amount is 0.6 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; then adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 3:1:1 for second defibering and dispersing by 10000r, adding water to adjust the mass concentration of paper pulp to 0.02%, and defibering and dispersing by 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a paper industry former with 200 meshes to obtain wet paper sheets of mixed paper, and then squeezing and drying at 110 ℃ to obtain raw paper of the PBO fiber paper base material; and (3) performing calendaring on the prepared base paper of the PBO fiber paper base material for 1 time at the calendaring temperature of 300 ℃, the calendaring line pressure of 130N/mm and the calendaring roller speed of 6m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 7

Immersing oven-dried PBO chopped fibers with the length of 7mm into a NaOH solution with the mass fraction of 3% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for preparation; putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r according to the mass ratio of 4:1, adding polyvinyl alcohol as a dispersing agent during fluffing, wherein the addition amount is 0.7 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; finally, adding the PBO chopped fibers, the meta-aramid chopped fibers and the meta-aramid fibrids according to the mass ratio of 4:1:5 of the PBO chopped fibers, the meta-aramid fibrids and the meta-aramid fibrids to carry out secondary defibering and dispersing of 10000r, adding water to adjust the mass concentration of the paper pulp to 0.04%, and defibering and dispersing of 2000r to prepare mixed pulp; dewatering and forming the defibered mixed slurry in a 200-mesh paper industry former to obtain wet paper sheets of mixed paper, and then squeezing and drying at 90 ℃ to obtain raw paper of the PBO fiber paper-based material; and performing calendaring on the prepared base paper of the PBO fiber paper base material for 1 time at a calendaring temperature of 280 ℃, a calendaring line pressure of 110N/mm and a calendaring roller speed of 5m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 8

The method comprises the steps of immersing oven-dried PBO chopped fibers with the length of 6mm into a NaOH solution with the mass fraction of 4% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r according to the mass ratio of 6:1, adding polyvinyl alcohol as a dispersing agent during fluffing, wherein the addition amount is 0.2% of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; finally, adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 6:1:3 for second defibering and dispersing by 10000r, adding water to adjust the mass concentration of paper pulp to 0.02%, and defibering and dispersing by 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a paper industry former with 200 meshes to obtain wet paper sheets of mixed paper, and then squeezing and drying at 100 ℃ to obtain raw paper of the PBO fiber paper base material; and (3) performing calendaring on the prepared base paper of the PBO fiber paper base material for 2 times at a calendaring temperature of 250 ℃, a calendaring line pressure of 110N/mm and a calendaring roller speed of 5m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

Example 9

And (2) immersing the oven-dried PBO chopped fibers with the length of 7mm into a NaOH solution with the mass fraction of 3% for pretreatment, then washing the pretreated PBO fibers to be neutral by using deionized water, and drying for later use. Putting the pretreated PBO chopped fibers and the meta-aramid chopped fibers into a fluffer for fluffing and dispersing 10000r according to the mass ratio of 7:1, adding polyvinyl alcohol as a dispersing agent during fluffing, wherein the addition amount is 0.7 percent of the absolute dry mass sum of the PBO chopped fibers and the meta-aramid chopped fibers; then adding aramid fibrids according to the mass ratio of PBO chopped fibers, meta-aramid chopped fibers and meta-aramid fibrids of 7:1:2 to carry out secondary defibering and dispersing of 10000r, adding water to adjust the mass concentration of paper pulp to 0.04%, and defibering and dispersing of 2000r to prepare mixed slurry; dewatering and forming the defibered mixed slurry in a paper industry former with 200 meshes to obtain wet paper sheets of mixed paper, and then squeezing and drying at 110 ℃ to obtain raw paper of the PBO fiber paper base material; and performing calendaring on the prepared base paper of the PBO fiber paper base material for 1 time at a calendaring temperature of 250 ℃, a calendaring line pressure of 100N/mm and a calendaring roller speed of 5m/min by using a high-temperature calendaring machine to obtain the base paper of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material.

In the embodiment of the present invention, the performance of the poly-p-phenylene benzobisoxazole fiber paper base material is detected, and the detection result is shown in the following table:

as can be seen from the above table, the typical product (the quantitative ratio is 42 +/-3 g/m) prepared by the preparation method of the poly-p-phenylene benzobisoxazole fiber paper base material for the high-temperature resistant honeycomb core material provided by the invention²) Has high mechanical strength; as can be seen from the thermal shrinkage rate at 300 ℃, in a certain range, with the increase of the proportion of the PBO chopped fibers, the thermal stability is also obviously improved, and the comprehensive performance can also meet the performance requirement of the high-temperature resistant honeycomb on the paper-based material.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.