Polyacrylonitrile Copolymer Cyclization Control for Carbon Fiber
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high energy consumption and cost associated with the stabilization process in carbon fiber production, particularly the cyclization reaction, hinder the economical efficiency and physical/mechanical properties of carbon fibers.
Innovation Solution
A method involving the production of a polyacrylonitrile-based copolymer by polymerizing a monomer mixture with an acrylate-based comonomer, such as butyl acrylate, to control the cyclization reaction, reducing energy consumption and improving the properties of carbon fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional PAN fiber is used for carbon fiber production, then the fiber can be converted to carbon fiber through stabilization and carbonization processes, but the stabilization process consumes high energy and has slow reaction rate
Solution Approach 1:
The invention modifies the chemical composition parameters of the PAN fiber by introducing specific comonomers (carboxylic acid-based comonomer at 0.1-5 wt% and acrylate-based comonomer at 4-20 wt%) during polymerization. This changes the thermal and chemical properties of the fiber, enabling the stabilization reaction to proceed at lower temperatures (reducing energy consumption) while maintaining or improving reaction rate through enhanced cyclization behavior.
2Temperature
If high heat treatment temperature of about 1300°C or higher is applied to carbon fiber, then the characteristics of carbon fiber can be greatly changed, but the production cost becomes high
Solution Approach 1:
The invention performs preliminary chemical modification during the polymerization stage by incorporating carboxylic acid-based and acrylate-based comonomers into the PAN chain structure. This preliminary action creates pre-reactive sites that facilitate easier and lower-temperature stabilization and carbonization processes later, reducing the ultimate heat treatment temperature needed and thereby lowering production costs.
3Speed
If the cyclization reaction proceeds at high temperature, then the reaction rate increases, but fiber damage occurs and shrinkage increases
Solution Approach 1:
The invention changes the chemical structure parameters of the polymer by incorporating specific comonomers that modify the cyclization reaction characteristics. The carboxylic acid-based comonomer introduces catalytic sites that accelerate cyclization at lower temperatures, while the acrylate-based comonomer modifies the chain flexibility and heat distribution, enabling fast reaction rates without fiber damage or excessive shrinkage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces energy consumption in the oxidation stabilization reaction, enhances the physical and mechanical properties of carbon fibers, and lowers production costs by stabilizing the cyclization reaction at lower temperatures.
Implementation Method 1
The cyclization reaction is an exothermic reaction, which is preferable to proceed at a low temperature in order to reduce degradation and economical advantage
Implementation Method 2
The stabilization process (or the chlorination process or the oxidation stabilization process) refers to a heat treatment process performed in a temperature range of about 200° C. to about 400° C. while applying a constant tension in an oxidizing or air atmosphere
Implementation Method 3
producing a polyacrylonitrile (PAN)-based copolymer by polymerizing a monomer mixture including an acrylonitrile-based monomer, a carboxylic acid-based comonomer, and an acrylate-based comonomer
Data Source
AI summary
The present invention relates to a method for producing a polyacrylonitrile-based fiber, wherein the method polymerizes a monomer mixture including an acrylonitrile-based monomer, a carboxylic acid-based comonomer, and an acrylate-based comonomer, wherein the acrylate-based comonomer includes the steps of producing a polyacrylonitrile-based copolymer so as to be included in an amount of 4 to 20 parts by weight based on 100 parts by weight of the monomer mixture, fiberizing the polyacrylonitrile-based copolymer, oxidizing and stabilizing the fiberized polyacrylonitrile-based copolymer, which may control the oxidation stabilization reaction, particularly the cyclization reaction. Accordingly, the energy consumption of the oxidation stabilization reaction may be reduced, economical efficiency of the production of polyacrylonitrile-based fiber may be obtained, and the physical and mechanical properties of the carbon fiber may be improved.