PTMPS Polymer Membrane Non-Fluoropolymer Filtration
Solution Overview
Problem
There is a need for a non-fluoropolymer article that demonstrates the positive attributes of fluoropolymers, such as high strength, high porosity, and high crystallinity, particularly for applications where microporous fluoropolymer membranes are used.
Innovation Solution
The development of a poly (tetramethyl-p-silphenylenesiloxane) (PTMPS) polymer membrane with a melting point from about 130° C. to about 150° C., crystallinity of at least 70%, porosity greater than 30%, and a microstructure of nodes interconnected by fibrils, processed below the melting temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If microporous fluoropolymer membranes are used to achieve high strength, high porosity, and high crystallinity, then the article demonstrates favorable attributes for filtration and separation applications, but the use of fluorochemical compounds is undesirable due to environmental and health concerns
Solution Approach 1:
The patent changes the chemical composition parameter by replacing fluoropolymer materials with poly (tetramethyl-p-silphenylenesiloxane) polymer, maintaining the desired physical properties (strength, porosity, crystallinity) while eliminating harmful fluorochemical compounds. The polymer is processed below its melting temperature to achieve the required microstructure and properties without using problematic substances.
Solution Approach 2:
The patent employs a non-fluoropolymer alternative that can be processed and discarded without the environmental persistence concerns associated with fluoropolymers. The PTMPS polymer articles provide the necessary performance for filtration and separation applications while avoiding the long-term environmental impact of fluorochemical compounds.
2Strength
If poly (tetramethyl-p-silphenylenesiloxane) polymer is processed below melting temperature to achieve high crystallinity and strength, then the article attains favorable mechanical properties, but the processing temperature range is limited
Solution Approach 1:
The patent utilizes the phase transition properties of poly (tetramethyl-p-silphenylenesiloxane) polymer by processing it in the solid state below its melting temperature (130°C to 150°C). This approach allows the polymer to achieve high crystallinity (at least 70%) and strength through controlled deformation and orientation of polymer chains without melting, thereby attaining favorable mechanical properties while working within a limited but sufficient temperature range.
Data Source
AI summary
Poly(tetramethyl-p-silphenylenesiloxane) (PTMPS) membranes and porous articles made therefrom that have a matrix tensile strength in at least one direction from about 1 MPa to about 50 MPa, a matrix modulus greater than about 100 MPa in at least one direction, a porosity greater than about 30%, and a microstructure of nodes interconnected by fibrils are provided. The PTMPS polymer forming the PTMPS membranes and porous articles has a crystallinity of at least about 70%, a polydispersity from 1 to 5, and a weight average molecular weight from about 350 kDa to about 5 MDa. The PTMPS membranes may be asymmetric, meaning that the observed pore structure on one side of the PTMPS membrane is different than the pore structure on the opposing side of the PTMPS membrane. Methods of forming porous PTMPS articles are provided. Dense PTMPS articles and methods of making the same are also provided.