Semicrystalline Polyphenylsulfone via Solvent-Induced Crystallization
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Solution Overview
Problem
Polyphenylsulfones, despite their heat and chemical resistance, are not suitable for additive manufacturing due to their amorphous nature, and existing methods to create semicrystalline forms are either hydroxyl-terminated or require halogenated solvents.
Innovation Solution
A method involving solvent-induced crystallization of polyphenylsulfone using a mixture of solvents and non-solvents to produce end-capped semicrystalline polyphenylsulfone particles with controlled hydroxyl group content and melting points, suitable for additive manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If polyphenylsulfone is used in amorphous form, then heat resistance and chemical resistance are maintained, but it cannot be used in applications requiring semicrystalline polymer structure
Solution Approach 1:
The patent changes the physical state parameter of polyphenylsulfone from amorphous to semicrystalline by controlling crystallization conditions, enabling the material to be used in applications requiring semicrystalline structure while maintaining its inherent heat and chemical resistance properties
Solution Approach 2:
The patent utilizes phase transition from amorphous to crystalline state through controlled cooling and crystallization processes, transforming the material's structural properties to enable new applications in additive manufacturing and other fields requiring semicrystalline polymers
2Stability of the object's composition
If Takekoshi's method is used to prepare semicrystalline polyphenylsulfone, then semicrystalline structure is achieved, but the product is hydroxyl-terminated and vulnerable to oxidation
Solution Approach 1:
The patent extracts and removes hydroxyl end groups from the polyphenylsulfone chains through specific purification and end-group modification procedures, eliminating the source of oxidation vulnerability while preserving the semicrystalline structure achieved through controlled crystallization
Solution Approach 2:
The patent converts the potentially harmful hydroxyl end groups into beneficial end-capping groups through chemical modification, transforming the oxidation vulnerability into an opportunity to create more stable end groups that enhance overall material reliability
3Stability of the object's composition
If Takekoshi's method is used to prepare semicrystalline polyphenylsulfone, then semicrystalline structure is achieved, but crystallization occurs in polymerization reaction mixture requiring halogenated aromatic solvents
Solution Approach 1:
The patent extracts and removes halogenated aromatic solvents from the crystallization process by using alternative non-halogenated solvents and performing crystallization after polymerization is complete, eliminating the harmful environmental and health effects associated with halogenated solvent usage
Solution Approach 2:
The patent inverts the traditional sequence by first completing polymerization to form amorphous polyphenylsulfone, then separately inducing crystallization in a different solvent system, thereby separating the polymerization and crystallization steps to avoid requiring halogenated solvents during the process
4Stability of the object's composition
If existing methods are used to create semicrystalline polyphenylsulfone, then crystalline structure is achieved, but hydroxyl group content is not controlled
Solution Approach 1:
The patent implements feedback control by monitoring hydroxyl group content during the crystallization and purification processes, using analytical methods to measure end-group concentration and adjusting process parameters to maintain hydroxyl content below specified thresholds, thereby achieving precise control over material composition
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 method yields semicrystalline polyphenylsulfone with enhanced oxidation resistance and controlled melting points, enabling its use in additive manufacturing techniques like selective laser sintering and jet fusion, while avoiding hydroxyl termination and halogenated solvents.
Implementation Method 1
A method involving solvent-induced crystallization of polyphenylsulfone using a mixture of solvents and non-solvents to produce end-capped semicrystalline polyphenylsulfone particles
Implementation Method 2
irradiating the working area with first radiation effective to heat the first layer to a temperature below and within 10°C of a melting onset temperature of the semicrystalline polyphenylsulfone particles; and irradiating the working area with second radiation effective to heat the first layer to a temperature above a melting point of the semicrystalline polyphenylsulfone particles
Data Source
AI summary
A semicrystalline polyphenylsulfone, has the structure wherein n and R are defined herein. The semicrystalline polyphenylsulfone, which exhibits a melting point in a range of 215 to 270 °C, can be prepared from amorphous polyphenylsulfone using a solvent-induced crystallization method. An additive manufacturing method utilizing particles of the semicrystalline polyphenylsulfone is described.