Blow Molding Polyimide/Polyamide Blends via Organo Phosphorus Additives
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Solution Overview
Problem
Polyimide/polyamide blends are difficult to process into large parts by blow molding due to low melt viscosity and low melt elasticity, especially at high temperatures required for plasticizing polyimide and melting crystalline polyamide resins.
Innovation Solution
Incorporating mono-functional or di-functional organo-phosphorus compounds into polyimide/polyamide blends to enhance melt viscosity and melt elasticity, achieving a suitable composition with 30-70 wt% polyamide, 70-30 wt% polyimide, and 0-40 wt% reinforcing filler, which results in high melt viscosity and elasticity suitable for blow molding, along with additives like alkali metal iodide, copper salts, or hindered phenol compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polyimide/polyamide blends are processed at high temperatures to plasticize polyimide and melt crystalline polyamide resins, then the resins become processable, but the melt viscosity and melt elasticity become too low for blow molding
Solution Approach 1:
The patent changes the chemical composition parameters by introducing organo phosphorus compounds (specifically phosphites and phosphonites) into the polyimide/polyamide blend. This chemical parameter change modifies the melt rheology to achieve appropriate viscosity and elasticity for blow molding while maintaining processability at high temperatures
Solution Approach 2:
The patent creates a composite material system by combining polyimide, polyamide, and organo phosphorus compounds into a multi-component blend. This composite approach allows the system to simultaneously achieve processability from the polymer blend and appropriate melt rheology from the phosphorus compound additive
2Reliability
If polyimide/polyamide blends are used to achieve combined performance features, then heat resistance and dimensional stability are improved, but the blends become difficult to melt process into large parts by blow molding
Solution Approach 1:
The organo phosphorus compound acts as an intermediary substance that mediates between the conflicting requirements of heat resistance (inherent to polyimide/polyamide) and blow molding processability. The phosphorus compound modifies melt rheology without compromising the thermal performance of the base polymer blend
Solution Approach 2:
The patent modifies the rheological parameters of the blend by adding organo phosphorus compounds, changing the melt viscosity and elasticity parameters to enable blow molding while preserving the thermal properties of the polyimide/polyamide system
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 modified blends exhibit a melt viscosity ratio of 4.0 to 16.0 at 330°C, achieving high heat resistance, impact strength, and tensile strength, enabling the production of blow molded articles with uniform wall thickness and high thermal stability.
Implementation Method 1
the use of mono functional or difunctional organo phosphorus compounds results in polyimide/polyamide blends having high melt elasticity and high melt viscosity suitable for blow molding
Implementation Method 2
at the high temperatures, often greater than 300° C., needed to plasticize the polyimide and melt crystalline polyamide resins
Implementation Method 3
heating the dried thermoplastic composition in a screw driven melt processing device to a temperature of 270 to 370° C. to form a molten composition
Data Source
AI summary
Thermoplastic compositions comprising polyamide, polyimide, an organo phosphorus compound and an optional reinforcing filler are described. The subject compositions are useful in blow molding methods. A method of blow molding is also described as well as articles made by the method.