Preparation of polybenzoxazole

A technology of polybenzoxazole and polyphosphoric acid, which is applied in the field of preparation of polybenzoxazole, can solve the problems of increased side reactions, long polymerization time, and high requirements, so as to shorten the polymerization reaction time, simplify the reaction process, The effect of improving productivity

Inactive Publication Date: 2008-12-17
SHANGHAI JIAO TONG UNIV +2
View PDF3 Cites 11 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are following deficiencies in the method: the first: a large amount of hydrogen chloride gas will be released in the process of removing hydrochloric acid by 4,6-diaminoresorcinol hydrochloride, and these gases will be in the viscous reaction solution A large amount of foam is generated in the medium, thereby reducing the stirring efficiency of the reaction system
Second: Hydrogen chloride is a highly corrosive gas, which makes the reaction very demanding on equipment materials, and the degassing process takes up a lot of time, usually about 10-20 hours
Third: in the process of dehydrochlorination gas, a large amount of foam produced makes 4,6-diaminoresorcinol hydrochloride adhere to the reactor wall, destroying the equimolar ratio of the two monomers, serious Affects the final molecular weight of the polymer
The 4th, it is very difficult to completely remove hydrochloric acid in the prior art, so phosphorus pentoxide usually adopts the mode of distributive addition,

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation of polybenzoxazole

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0014] Example 1

[0015] Add 5.2 kilograms of 4,6-diaminoresorcinol / terephthalic acid compound salt into the polyphosphoric acid solvent containing phosphorus pentoxide (wherein: 16.5 kilograms of polyphosphoric acid, 6.7 kilograms of phosphorus pentoxide) , under the protection of an inert gas, mix and dissolve for 3 hours at 60°C to form a polyphosphoric acid mixed solution of 4,6-diaminoresorcinol / terephthalic acid compound salt; the mixed solution is directly fed into the twin-screw , the set temperature of the screw is 120-190 ° C, the residence time is 50 minutes, and the yellow-green polybenzoxazole spinning slurry with stirring fluorescence is obtained, and the spinning slurry is washed with water to remove polyphosphoric acid, and obtain Polybenzoxazole. A small amount of this polymer was dissolved in methanesulfonic acid to prepare a solution with a concentration of 0.02-0.05g / dl, and its intrinsic viscosity at 30°C was determined to be 30.2dL / g.

Example Embodiment

[0016] Example 2

[0017] Add 6.8 kilograms of 4,6-diaminoresorcinol / terephthalic acid compound salt into the polyphosphoric acid solvent containing phosphorus pentoxide (wherein: 21.4 kilograms of polyphosphoric acid, 8.9 kilograms of phosphorus pentoxide) , under the protection of an inert gas, mix and dissolve for 2 hours at 80°C to form a polyphosphoric acid mixed solution of 4,6-diaminoresorcinol / terephthalic acid compound salt; the mixed solution is directly fed into the twin-screw , the set temperature of the screw is 150-200 ° C, the residence time is 30 minutes, and the yellow-green polybenzoxazole spinning slurry with stirring fluorescence is obtained, and the spinning slurry is washed with water to remove polyphosphoric acid, and obtain Polybenzoxazole. A small amount of this polymer was dissolved in methanesulfonic acid to prepare a solution with a concentration of 0.02-0.05g / dl, and its intrinsic viscosity at 30°C was determined to be 32.5dL / g.

Example Embodiment

[0018] Example 3

[0019] Add 4.4 kilograms of 4,6-diaminoresorcinol / terephthalic acid compound salt into the polyphosphoric acid solvent containing phosphorus pentoxide (wherein: 13.7 kilograms of polyphosphoric acid, 6 kilograms of phosphorus pentoxide) , under the protection of an inert gas, mix and dissolve for 4 hours at 80°C to form a polyphosphoric acid mixed solution of 4,6-diaminoresorcinol / terephthalic acid compound salt; the mixed solution is directly fed into the twin-screw , the set temperature of the screw is 150-190 ° C, the residence time is 50 minutes, and a yellow-green polybenzoxazole spinning slurry with stirring fluorescence is obtained. The spinning slurry is washed with water to remove polyphosphoric acid, and obtain Polybenzoxazole. A small amount of this polymer was dissolved in methanesulfonic acid to prepare a solution with a concentration of 0.02-0.05g / dl, and its intrinsic viscosity at 30°C was determined to be 34.5dL / g.

[0020] The PBO slurry o...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Intrinsic viscosityaaaaaaaaaa
Intrinsic viscosityaaaaaaaaaa
Intrinsic viscosityaaaaaaaaaa
Login to view more

Abstract

The invention relates to a preparation method of polybenzoxazole, which comprises the steps: 4, 6-Diaminoresorcinol/terephthalic acid composite salt is added into a polyphosphoric acid solution containing a certain amount of phosphoric anhydride and fully blended and dissolved directly at a temperature of 30 DEG C to 80 DEG C under the protection of inert gases, thereby preparing the polyphosphoric acid solution of 4, 6-Diaminoresorcinol/terephthalic acid composite salt which carries out a reactive extrusion polymerization to obtain the polybenzoxazole with twin screws. The invention directly mixes the 4, 6-Diaminoresorcinol/terephthalic acid, phosphoric anhydride and polyphosphoric acid to prepare into solution which carries out twin-screw polymerization without needing to carry out pre-polymerization, thus greatly shortening the polymerization time, saving time and increasing the production efficiency.

Description

technical field [0001] The invention relates to a preparation method of polybenzoxazole, and the prepared polymer has wide application prospects in the fields of high-performance composite materials, body armor, flame-retardant materials and the like. The invention belongs to the technical field of high-performance fiber material preparation. Background technique [0002] Polybenzoxazole (PBO) fiber - the abbreviation of cis-polyparaphenylene benzobisoxazole (PBO) fiber. The fiber has a 575kg / cm 2 Tensile strength and 28000kg / cm 2 The main performance indicators such as the initial modulus, the limiting oxygen index LOI value of 68, and the decomposition temperature of 650 ° C are among the highest among organic and inorganic fibers at present. 1.4 times, and the specific gravity is 1.52-1.55g / cm 2 Only 1 / 5 of steel. Due to its superior performance, it has been regarded as a new generation of superfibers for advanced structural composite materials such as aerospace and ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C08G73/22
Inventor 史子兴印杰朱子康徐纪平
Owner SHANGHAI JIAO TONG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products