Cyclic Polyarylene Sulfide Prepreg for Fiber Impregnation
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Solution Overview
Problem
Current methods for producing fiber-reinforced molding substrates with thermoplastic resins, such as polyarylene sulfides, face challenges in achieving economic efficiency, productivity, and maintaining dynamic properties due to high viscosity and pyrolysis issues, leading to environmental contamination and unsatisfactory mechanical properties.
Innovation Solution
A method involving the continuous feeding of a bundle of continuous reinforcing fibers, combining cyclic polyarylene sulfide, heating for ring-opening polymerization to convert it into polyarylene sulfide, and controlling the molecular weight to enhance impregnation and productivity, while minimizing voids and environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a high-molecular-weight thermoplastic resin is used as matrix resin to maintain dynamic properties, then the toughness and ductility are improved, but the melt viscosity increases making impregnation difficult and productivity low
Solution Approach 1:
The patent segments the matrix resin into two distinct components: a low-molecular-weight thermoplastic resin (molecular weight 10,000-100,000) that provides ease of impregnation, and a high-molecular-weight thermoplastic resin (molecular weight 100,000-1,000,000) that provides dynamic properties. This segmentation allows each component to fulfill its specific function without compromise.
Solution Approach 2:
The patent changes the molecular weight parameter of the thermoplastic resin from a single high value to a dual distribution including lower values (10,000-100,000), thereby reducing melt viscosity and improving impregnation performance while maintaining dynamic properties through the presence of higher molecular weight components.
2Productivity
If a low-molecular-weight thermoplastic resin is used as matrix resin to improve impregnation ease, then the productivity and economic efficiency are improved, but the dynamic properties of the molded product are significantly deteriorated
Solution Approach 1:
The patent segments the matrix resin into two distinct components: a low-molecular-weight thermoplastic resin (molecular weight 10,000-100,000) that provides ease of impregnation, and a high-molecular-weight thermoplastic resin (molecular weight 100,000-1,000,000) that provides dynamic properties. This segmentation allows each component to fulfill its specific function without compromise.
Solution Approach 2:
The patent creates a composite resin system combining low-molecular-weight and high-molecular-weight thermoplastic resins, where the low-molecular-weight component facilitates impregnation and the high-molecular-weight component ensures dynamic properties, achieving a synergistic effect greater than the sum of individual components.
3Ease of manufacture
If a low-molecular-weight thermoplastic resin is used for impregnation, then the impregnation performance is improved, but the resin undergoes pyrolysis at processing temperature generating environmental contamination and voids
Solution Approach 1:
The patent introduces a cyclic oligomer as an intermediary substance that converts to linear polymer at processing temperature. This intermediary approach allows the resin to maintain stability at processing temperatures (avoiding pyrolysis) while still achieving good impregnation performance through the cyclic structure's unique properties.
Solution Approach 2:
The patent changes the chemical structure parameter from linear thermoplastic resin to cyclic oligomer, which fundamentally alters the thermal behavior and stability characteristics, eliminating pyrolysis gas generation while maintaining impregnation capabilities.
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
This method enables easy and productive impregnation of polyarylene sulfide into reinforcing fibers, improving the economic efficiency and dynamic properties of the molding substrate, reducing environmental contamination, and enhancing the mechanical properties of the final product.
Implementation Method 1
heating the composite of the reinforcing fiber bundle and the cyclic polyarylene sulfide obtained in step (II) to 200°C to 450°C and subjecting the cyclic polyarylene sulfide to ring-opening polymerization to convert into polyarylene sulfide
Data Source
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AI summary
This invention relates to: a molding material comprising a bundle of continuous reinforcing fibers (A), a polyarylene sulfide prepolymer (B) comprising at least 50% by weight of cyclic polyarylene sulfide and having the weight average molecular weight of less than 10,000 or polyarylene sulfide (B') having the weight average molecular weight of 10,000 or greater and the degree of dispersion of 2.5 or lower, and thermoplastic resin (C); a prepreg comprising a resin composition comprising the polyarylene sulfide prepolymer (B) impregnated into a reinforcing fiber; and a method for producing a fiber-reinforced molding substrate comprising step (I) of continuously feeding a bundle of continuous reinforcing fibers, step (II) of combining cyclic polyarylene sulfide with the reinforcing fiber bundle, step (III) of heating the composite obtained in step (II) to subject the cyclic polyarylene sulfide to ring-opening polymerization to convert into polyarylene sulfide, and step (IV) of cooling the composite obtained in step (III) and withdrawing the same.