Sulfur-Modified Polyvinyl Acetate Melting Point
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Solution Overview
Problem
Unmodified polyvinyl acetate polymers have limitations in terms of melting point and stability, and there is a need for a modified polymer that can utilize excess sulfur effectively, addressing environmental storage concerns and providing improved properties.
Innovation Solution
Sulfur is incorporated into polyvinyl acetate polymers in amounts between 50% and 70% by weight, increasing the melting point by 10°C to 50°C through a heating process that mixes elemental sulfur with the polymer at temperatures between 150°C and 200°C, resulting in a softer and more ductile material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If sulfur is added to polyvinyl acetate polymer, then the melting point increases and mechanical properties improve, but the polymer composition becomes more complex
Solution Approach 1:
The patent creates a composite material by combining polyvinyl acetate polymer with sulfur in specific weight ratios (30-70% sulfur). This composite structure allows the sulfur to modify the polymer's melting point and mechanical properties while maintaining a relatively simple two-component system that avoids excessive complexity
Solution Approach 2:
The patent systematically varies the sulfur content parameter (30-70% by weight) to optimize the melting point and mechanical properties. By controlling this single parameter within a defined range, the patent achieves improved material performance without requiring complex multi-parameter optimization
2Ease of operation
If sulfur is incorporated into the polymer, then the material becomes softer and more ductile, but the manufacturing process requires additional heating and mixing steps
Solution Approach 1:
The patent utilizes phase transitions by heating the polymer-sulfur mixture to temperatures above the polymer's melting point (150-200°C) to create a molten state where thorough mixing occurs. This phase transition approach enables efficient incorporation of sulfur while the subsequent cooling phase allows the material to solidify with the desired ductile properties
Solution Approach 2:
The patent performs preliminary mixing of sulfur with the polymer before final processing. This preliminary action ensures uniform distribution of sulfur throughout the polymer matrix, which simplifies subsequent processing steps and ensures consistent ductility in the final product
3Temperature
If high amounts of sulfur (50-70% by weight) are used to maximize property improvement, then the melting point increases by 10-50°C, but the cost-effectiveness decreases due to processing requirements
Solution Approach 1:
The patent employs partial action by using sulfur in the range of 30-70% by weight, with optimal results at 50-70%. This partial incorporation of sulfur provides sufficient melting point elevation (10-50°C) and mechanical property improvement without requiring 100% sulfur content, thereby balancing performance gains with processing costs
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 sulfur-modified polyvinyl acetate polymers exhibit increased melting points and improved mechanical properties, such as reduced strain hardening and increased ductility, while providing a cost-effective solution for utilizing abundant sulfur, suitable for applications in adhesives and concrete crack repair.
Implementation Method 1
heating process that mixes elemental sulfur with the polymer at temperatures between 150°C and 200°C
Data Source
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AI summary
Provided are a sulfur modified polymer composition, free from asphalt, bitumen or like compounds, and method of making same. The inclusion of 50% by weight sulfur, or greater, into the polymer composition results in a composition that is softer and having an increased melting point, relative to the unmodified polymer composition.