Polyphenylene Ether Composition for Flat Screen TV Back Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blends of poly(phenylene ether)s and rubber-modified polystyrenes face challenges in preserving physical and flame retardancy properties when using recycled plastic feedstocks, often requiring compatibilizers and resulting in insufficient properties for injection molding applications.
Innovation Solution
A composition comprising 32-46 weight percent poly(phenylene ether) with an intrinsic viscosity of 0.2-0.35 deciliter per gram, 30-49 weight percent post-consumer recycled rubber-modified polystyrene, 13-19 weight percent organophosphate ester, and 0.2-1.5 weight percent polymerized acrylonitrile residue, which eliminates the need for compatibilizers and maintains the physical and flame retardancy properties of blends prepared from virgin resins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If compatibilizer (olefin-epoxy copolymer) is used to blend poly(phenylene ether) and acrylonitrile-butadiene-styrene copolymer, then compatibility between polymers is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts and eliminates the compatibilizer component from the blend formulation. By using virgin poly(phenylene ether) with controlled molecular weight (intrinsic viscosity 0.2-0.35 dL/g) combined with recycled rubber-modified polystyrene, the system achieves adequate compatibility without requiring the olefin-epoxy copolymer additive, thereby simplifying the composition and reducing manufacturing steps.
Solution Approach 2:
The invention changes the molecular weight parameter of the poly(phenylene ether) component by specifying an intrinsic viscosity range of 0.2-0.35 dL/g. This parameter control enables the polymer to blend effectively with recycled rubber-modified polystyrene without requiring additional compatibilizing agents, thus resolving the compatibility issue while avoiding added complexity.
2Loss of energy
If recycled rubber-modified polystyrene is used as feedstock, then waste reduction and energy conservation are improved, but physical and flame retardancy properties deteriorate
Solution Approach 1:
The invention changes the molecular weight parameter of the poly(phenylene ether) component by specifying an intrinsic viscosity range of 0.2-0.35 dL/g. This parameter control enables the polymer to blend effectively with recycled rubber-modified polystyrene without requiring additional compatibilizing agents, thus resolving the compatibility issue while avoiding added complexity.
Solution Approach 2:
The invention creates a composite material system combining virgin poly(phenylene ether) with controlled molecular weight and recycled rubber-modified polystyrene. This composite approach leverages the advantages of both virgin and recycled materials, maintaining adequate mechanical and flame retardancy properties while incorporating recycled content to reduce waste and energy consumption.
3Strength
If molecular weight of poly(phenylene ether) is increased to improve strength, then strength is improved, but melt viscosity increases making injection molding difficult
Solution Approach 1:
The invention optimizes the molecular weight parameter of poly(phenylene ether) by specifying an intrinsic viscosity range of 0.2-0.35 dL/g. This controlled molecular weight achieves an optimal balance between mechanical strength and processability, ensuring the material has sufficient strength while maintaining low enough melt viscosity for easy injection molding of large, thin parts.
Data Source
AI summary
A composition includes specific amounts of a poly(phenylene ether), a rubber-modified polystyrene, an organophosphate ester, and polymerized acrylonitrile residue. When combusted in air, the composition yields a specific amount of ash. The composition can be prepared using a post-consumer recycled rubber-modified polystyrene that contains as impurities acrylonitrile copolymer and a metal oxide pigment that survives combustion of the composition. The composition is useful for molding large, flat parts, such as back panels for flat screen televisions.