Optically Clear PVDF Copolymers via Delayed TFP Feed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyvinylidene fluoride (PVDF) and its copolymers, despite being chemically resistant, suffer from haziness, which limits their optical clarity, necessitating the development of optically clear PVDF or PVDF copolymers that retain chemical resistance.
Innovation Solution
Copolymers of vinylidene fluoride and 3,3,3-trifluoropropene are synthesized using a semi-batch emulsion polymerization process, where most or all of the 3,3,3-trifluoropropene is added as a delayed feed, resulting in materials with excellent optical clarity, high melting points, and flexible films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PVDF copolymers are used to maintain chemical resistance, then chemical resistance is improved, but optical clarity deteriorates due to haziness
Solution Approach 1:
The patent changes the compositional parameters by incorporating specific comonomers (TFP, HFP, or HFPE) at controlled levels (0.1-40 wt%) with VDF to reduce crystallinity below 23%, thereby improving optical clarity while maintaining chemical resistance through the copolymer structure
Solution Approach 2:
The patent creates composite copolymer materials combining VDF with fluorinated comonomers to achieve a new material system that exhibits both chemical resistance from the fluoropolymer backbone and optical clarity from reduced crystallinity and modified molecular structure
2Illumination intensity
If copolymer composition is adjusted to improve optical clarity, then optical clarity is improved, but manufacturing complexity increases due to semi-batch process requirements
Solution Approach 1:
The patent applies preliminary action by pre-planning the semi-batch polymerization process with staged comonomer addition, where VDF is polymerized first followed by controlled addition of TFP/HFP/HFPE to achieve target composition and optimize both optical clarity and process control
Solution Approach 2:
The patent uses periodic action through the semi-batch process where comonomers are added at specific intervals during polymerization to control composition and achieve desired optical properties while managing process complexity through systematic timing
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 copolymers exhibit high optical clarity with haze levels below 30% and light transmission greater than 85%, combined with high melting points and flexibility, making them suitable for various applications including optical equipment and industrial windows.
Implementation Method 1
Copolymers of vinylidene fluoride and 3,3,3-trifluoropropene are synthesized using a semi-batch emulsion polymerization process
Implementation Method 2
a vinylidene fluoride having a melting point of greater than 150° C., and a crystallinity of less than 23 percent
Data Source
AI summary
The invention relates to a copolymer composition of poly(vinylidene fluoride-trifluoropropene) copolymers. The copolymers formed have excellent optical properties, with very low haze, as well as high melting points, excellent flexibility and toughness.