Extruded polyacrylonitrile copolymer
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Solution Overview
Problem
Polyacrylonitrile (PAN) and its copolymers have poor flame retardant properties, and existing methods using halogenated chemicals are hazardous and environmentally toxic, while alternative treatments like hydrazine hydrate and organic diamines also pose safety and environmental concerns, and the wet-spinning process for producing PAN fibers is costly and hazardous.
Innovation Solution
A polymeric fiber derived from a copolymer of polyacrylonitrile and a halogen-free comonomer, incorporating metal ions or silicon, which is extruded to form a fiber with enhanced flame resistance and antimicrobial properties, avoiding the use of hazardous chemicals and processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If halogenated chemicals are used to improve flame retardant properties, then flame resistance is improved, but environmental toxicity and health hazards worsen
Solution Approach 1:
The invention changes the chemical composition parameters by using copolymers with specific comonomer content (5-30 mol%) and incorporating metal ions (1-15 wt%) or silicon (1-15 wt%), replacing halogenated chemicals with non-toxic alternatives that achieve flame resistance through different chemical mechanisms
Solution Approach 2:
The invention creates composite materials by combining polyacrylonitrile with metal ions or silicon, forming a new material system that achieves flame retardancy through the composite structure rather than relying on halogenated additives
2Reliability
If hydrazine hydrate is used to treat PAN to improve flame resistance, then flame retardant properties are improved, but safety hazards and environmental toxicity worsen
Solution Approach 1:
The invention changes the chemical treatment approach by incorporating metal ions or silicon during extrusion rather than using hydrazine hydrate post-treatment, fundamentally altering the chemical process to eliminate safety hazards associated with explosive and carcinogenic substances
Solution Approach 2:
The invention extracts and eliminates the hazardous hydrazine hydrate treatment step from the process, replacing it with a safer extrusion-based incorporation of metal ions or silicon that achieves the same flame retardant effect without the harmful chemicals
3Productivity
If wet-spinning process is used to produce PAN fibers, then fiber production is achieved, but process complexity and safety hazards worsen
Solution Approach 1:
The invention extracts and eliminates the complex wet-spinning process entirely, replacing it with a simpler extrusion process that directly produces the flame-retardant fiber without requiring specialized solvent handling equipment and multi-step processing
Solution Approach 2:
The invention replaces the mechanical and chemical complexity of wet-spinning with a simpler extrusion-based system, substituting the need for solvent recovery systems and complex process control with a more straightforward manufacturing approach
4Ease of manufacture
If conventional PAN copolymers are used, then ease of manufacture is maintained, but flame resistance deteriorates
Solution Approach 1:
The invention modifies the polymer composition parameters by incorporating metal ions (1-15 wt%) or silicon (1-15 wt%) into the copolymer structure during extrusion, changing the material properties to achieve flame resistance while maintaining ease of manufacture through a single-step process
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
The resulting fiber exhibits improved flame resistance, as indicated by a limiting oxygen index of at least 40, and antimicrobial properties, reducing the risk of combustion and environmental toxicity, while also simplifying the production process and reducing hazardous chemical handling.
Implementation Method 1
extruding the copolymer melt through a die to form a fibre
Data Source
AI summary
The invention relates to a polymeric fibre derived from a copolymer of polyacrylonitrile and a comonomer. The fibre comprises a metal ion and/or silicon at from about 1 to about 15 wt %. A process for making the fibre is also described.