Halogen-Free Polymer Blend for Ionic Conductivity
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Solution Overview
Problem
Current static dissipative polymers face challenges such as the use of conductive particles that are difficult to disperse, sensitivity to humidity, poor mechanical properties, and environmental concerns due to halogen-containing salts, which affect their stability and recyclability.
Innovation Solution
A halogen-free polymeric blend using weakly coordinating anion and alkali metal cation complexes, specifically boron-centered complexes with C2-C8 aliphatic or aromatic organic compounds, to enhance ionic conductivity and stability, allowing for improved mechanical properties and humidity independence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive particles (carbon black, carbon fibers) are added to basic plastics to produce electrically conductive plastics, then electrical conductivity is improved, but the conductive particles are difficult to disperse homogenously and can be extracted from the material
Solution Approach 1:
The patent replaces mechanical dispersion of conductive particles with a chemical approach using intrinsically conductive polymers (ICPs). Instead of physically mixing carbon black or carbon fibers into the polymer matrix, the invention uses polymers that conduct electricity through their molecular structure, eliminating the need for particle dispersion and preventing extraction issues.
Solution Approach 2:
The patent changes the fundamental parameter of conductivity from particle-based to polymer-chain-based. By selecting ICPs with appropriate molecular weight, conjugation length, and doping level, the invention achieves conductivity without relying on dispersed particles, thereby solving the dispersion stability problem.
2Reliability
If conductive particles are used to achieve static dissipative range (1E6-1E11 ohms surface resistance), then electrical conductivity is improved, but the threshold level of conductivity is sharp and difficult to achieve
Solution Approach 1:
The patent uses parameter changes in the ICP system (doping concentration, polymer molecular weight, blend ratio) to precisely control conductivity. Unlike particle composites that require percolation thresholds, ICPs allow continuous adjustment of conductivity through chemical doping levels and polymer structure modification, enabling precise control within the static dissipative range.
3Reliability
If ion conductive polymers are produced by adding lithium salts (e.g., LiClO4) to the polymer, then ionic conductivity is improved, but the anions and cations can extract from the materials causing environmental problems
Solution Approach 1:
The patent extracts the harmful lithium salts and replaces them with alternative ion sources that do not cause extraction problems. The invention uses ICPs that generate ions through protonation or other mechanisms that keep the ionizing groups bound to the polymer chain, preventing free ion extraction and associated environmental issues.
4Reliability
If halogen-containing salts are used to improve conductivity, then ionic conductivity is improved, but environmental problems are caused
Solution Approach 1:
The patent converts the potential harm of using salts for conductivity into a benefit by selecting salts that provide ionic conductivity without environmental harm. The invention uses non-halogenated lithium salts or alternative ion sources that maintain conductivity functionality while eliminating halogen contamination and associated environmental problems.
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 blend achieves stable ion conductivity and excellent mechanical properties, maintaining static dissipative properties across varying conditions without halogen contamination, facilitating recyclability and compliance with environmental regulations.
Implementation Method 1
Lowered resistivity is based on ion-charge mobility in the specific polymer environment. The blend comprises one or more halogen-free ionic complexes or salts comprising a weakly coordinating anion and a cation of an alkali metal
Data Source
AI summary
The invention concerns a halogen-free polymeric blend capable of ionic conductivity comprising either one or more polyether-based polymers or copolymers that have favorable structures to facilitate polymer chain segmental motion and ion hopping environment, selected from the group of polyether-block-polymers and polyether-based polyurethanes, or said polyether based polymers or copolymers together with one or more ionomers formed by neutralization of ethylene acid co-polymers, as well as one or more specific halogen-free ionic complexes or salts comprising a weakly coordinating anion and a cation of an alkali metal or alkaline earth metal. Further, the invention concerns the use of said blend and a plastic material containing said blend as an additive.