VDF Fluoroelastomer Composition for Low Tg and Clean End Groups
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluoroelastomers lack a combination of low glass transition temperature, high chemical resistance, improved mechanical properties, and reduced -COF polymer end groups, which are essential for effective performance across a wide temperature range, particularly in high and low temperatures.
Innovation Solution
Development of VDF fluoroelastomers with a glass transition temperature between -10°C and -35°C, comprising VDF, a specific monomer, and one or more comonomers like TFE, PMVE, and HFP, with improved mechanical properties and chemical resistance, and minimal -COF polymer end groups, achieved through a polymerization process involving coagulation, washing, and FT-IR spectroscopy for end group detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If perfluorovinylethers with longer perfluorooxyalkylene units are used to lower Tg, then glass transition temperature decreases, but vinylether reactivity drastically decreases making it difficult to obtain polymers with sufficiently high molecular weight
Solution Approach 1:
The patent changes the chemical structure parameters of the vinylether monomer by selecting specific perfluorooxyalkylene unit lengths (n=1 or n=2) to optimize the balance between achieving low Tg and maintaining sufficient polymerization reactivity. This parameter optimization allows the polymer to reach the required molecular weight while still providing the desired low-temperature elastomeric properties.
2Ease of manufacture
If -COF end groups are present in fluoroelastomers, then polymerization is simpler, but mechanical properties and thermal resistance worsen
Solution Approach 1:
The patent extracts and eliminates the harmful -COF end groups from the polymer structure by using vinylethers with specific perfluorooxyalkylene units that do not form these groups during polymerization. This removal of the harmful component allows the polymer to achieve high mechanical properties and thermal resistance without compromising the polymerization process.
3Productivity
If unreacted monomer recovery processes are implemented, then polymerization yield improves, but process complexity and cost increase
Solution Approach 1:
The patent implements self-service by designing a polymerization system where the vinylether monomer reacts completely without requiring external recovery processes. The specific monomer structure enables high reactivity and complete conversion, making the system self-sufficient and eliminating the need for complex post-processing equipment.
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 resulting fluoroelastomers exhibit enhanced chemical resistance, mechanical properties, and compression set across a wide temperature range, with high polymerization kinetics and yields, eliminating the need for expensive unreacted monomer recovery processes.
Implementation Method 1
The fluoroelastomers of the present invention are obtainable by a polymerization process with an improved productivity
Implementation Method 2
the -COF polymer end groups are determined by FT-IR spectroscopy on a polymer film having a thickness from 50 to 300 micron
Data Source
AI summary
VDF-based curable fluorelastomers, having a glass transition temperature from -10°C to -35°C, comprising: B) monomer of formula: CF2=CFOCF2OCF3 (a), C) one or more comonomers selected from: tetrafluoroethylene (TFE), per- fluoromethylvinylether (PMVE), perfluoropropene (HFP), and an amount of -COF end groups in the polymer lower than the sensitivity limit of the method which uses the FT-IR spectroscopy described in the present application.