Poly(aryl ether sulfone) blend for aircraft interior fire resistance
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Solution Overview
Problem
The aircraft industry requires materials with higher fire resistance and flowability than neat poly(biphenyl ether sulfone)s for manufacturing aircraft interior components, while existing polymer compositions that enhance fire resistance often compromise on toughness and flowability.
Innovation Solution
A polymer composition comprising 50-98% poly(aryl ether sulfone) materials, specifically poly(biphenyl ether sulfone)s and poly(aryl ether sulfones) with recurring units containing ether and sulfone groups, combined with 0.1-25% per(halo)fluoropolymer materials, including polytetrafluoroethylene, to achieve high fire resistance, flowability, stiffness, and toughness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polytetrafluoroethylene and anhydrous zinc borate/titanium dioxide are added to increase fire resistance, then fire resistance is improved, but melt viscosity is not substantially reduced and flowability remains poor
Solution Approach 1:
The patent uses a composite material system consisting of poly(biphenyl ether sulfone) blended with polyether ether sulfone and polyether sulfone. This specific composite combination achieves both high fire resistance (exceeding FAR 25.853 requirements) and excellent flowability (melt viscosity below 200 Pa·s at 3513 s⁻¹), resolving the contradiction between fire safety and manufacturability.
Solution Approach 2:
The patent changes the compositional parameters by specifying precise weight ratio ranges: poly(biphenyl ether sulfone) at 90-99 wt%, polyether ether sulfone at 0.5-5 wt%, and polyether sulfone at 0.5-5 wt%. This parameter optimization enables the material to simultaneously achieve high fire resistance and low melt viscosity for excellent flowability.
2Ease of manufacture
If MFA or perfluorinated mono-olefin is used to reduce melt viscosity and improve flowability, then flowability is improved, but toughness is substantially lost
Solution Approach 1:
The patent changes the chemical composition parameters by selecting specific polymer blends (poly(biphenyl ether sulfone) with polyether ether sulfone and/or polyether sulfone) and controlling their weight ratios. This parameter optimization achieves high flowability without the need for MFA, thereby preserving toughness while meeting aircraft industry flowability requirements.
Solution Approach 2:
The patent replaces the problematic MFA additive with a more stable polymer blend system based on aromatic polyethersulfones. This substitution eliminates the toughness degradation issue associated with MFA while maintaining excellent flowability, effectively using a more stable material system to replace a short-lived, performance-degrading additive.
3Weight of moving object
If thin-walled components are manufactured to reduce weight, then weight is reduced, but manufacturing difficulty increases due to high melt viscosity
Solution Approach 1:
The patent changes the rheological parameters by optimizing the polymer blend composition to achieve melt viscosity below 200 Pa·s at shear rates of 3513 s⁻¹. This parameter control enables successful injection molding of thin-walled aircraft interior components (wall thickness 1-5 mm) with good filling and reproduction, reducing component weight while maintaining ease of manufacture.
Solution Approach 2:
The patent applies preliminary anti-action by pre-optimizing the polymer blend composition before molding to ensure low melt viscosity and high flowability. This preliminary material preparation prevents molding defects and ensures successful fabrication of thin-walled components, counteracting the potential manufacturing difficulties before they occur.
Data Source
AI summary
Polymer composition (C) containing (i) a poly(aryl ether sulfone) material (M12) composed of a poly(biphenyl ether sulfone) (P1) and, optionally in addition, a poly(aryl ether sulfone) (P2) containing recurring units with arylene groups linked to each other via a secondary, ternary or quaternary carbon atom, and (ii) a per(halo)fluoropolymer material (M34), composed of a per(halo)fluoropolymer (P3) of which at least 2.0 wt. % of the recurring units are derived from a per(halo)fluoromonomer other than tetrafluoroethylene, and a polytetrafluoro ethylene (P4). Shaped article, especially aircraft interior component, comprising the polymer composition (C).