Polybenzimidazole Solution Polymerization High Solids
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Solution Overview
Problem
Current methods for producing polybenzimidazole (PBI) via solution polymerization face challenges with low monomer concentrations and decreasing intrinsic viscosity (IV) as monomer concentration increases, limiting commercial exploitation due to insufficient high IV and high solids content.
Innovation Solution
A solution polymerization method involving reacting an organic compound with at least 4 amino groups and an organic aldehyde adduct in a solvent such as N,N-dimethylacetamide, with reactants comprising at least 10% by weight, to achieve a polybenzimidazole with an intrinsic viscosity of at least 0.40 dl/g, using conditions like temperatures from 100°C to 285°C and atmospheric pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solution polymerization is conducted at low monomer concentrations, then the polymerization can proceed, but the intrinsic viscosity (IV) of the resulting polymer is insufficient
Solution Approach 1:
The patent changes the concentration parameter by conducting polymerization at high monomer concentrations (10-50 wt%) rather than low concentrations, which simultaneously achieves high solids content and high intrinsic viscosity in the resulting polymer
Solution Approach 2:
The patent uses pre-formed adducts (such as bisulfite adducts of dialdehydes or hemiaminal adducts of diamines with aldehydes) as polymerization reactants. These adducts are prepared in advance and then used in the polymerization reaction, enabling high concentration processing while maintaining polymer quality
2Quantity of substance
If the monomer concentration in the solution increases, then the solids content increases, but the polymer's intrinsic viscosity (IV) decreases
Solution Approach 1:
The patent inverts the conventional relationship by demonstrating that high monomer concentration (10-50 wt%) combined with specific adduct reactants actually produces high IV polymers (0.4-1.2 dl/g), reversing the traditional trend where high concentration leads to low IV
Solution Approach 2:
The patent introduces adducts (bisulfite adducts, hemiaminal adducts) as intermediary compounds that mediate between high concentration requirements and high IV requirements. These adducts serve as stable, high-concentration reactants that polymerize to form high IV polymers
3Reliability
If melt/solid polymerization is used, then high intrinsic viscosity polymer can be produced, but the production cost is high
Solution Approach 1:
The patent employs readily available, inexpensive adducts (such as bisulfite adducts which are stable crystalline solids) as reactants, replacing expensive commercial monomers or requiring complex purification steps, thereby reducing production cost while maintaining high IV output
Solution Approach 2:
The patent changes the physical state and concentration parameters by using high solids content solution polymerization (10-50 wt% monomer/adduct in solvent) instead of melt processing, achieving high IV at lower cost through solution chemistry with common solvents
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
This method successfully increases the solids content in polymerization, resulting in polybenzimidazole with higher intrinsic viscosity, making it suitable for industrial applications such as fiber and film production by achieving IV values up to 1.20 dl/g and higher polymer weight % solids, overcoming previous limitations.
Implementation Method 1
reacting, in a solution, an organic compound having at least 4 amino groups with an organic aldehyde adduct
Data Source
Figure 1
Figure 2(A)~2(C)
Figure 3
AI summary
A method of making a polybenzimidazole (PBI) includes the steps of: reacting, in a solution, an organic compound having at least 2 amino groups with an organic aldehyde adduct, the reactants comprise at least 8% by weight of the solution. A solvent of the solution may be selected from the group of: N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), tetramethylene sulfone, and combinations thereof. The organic aldehyde adduct may be an organic aldehyde bisulfite adduct. The organic aldehyde portion of the organic aldehyde adduct being aliphatic, alicyclic, aromatic, heterocyclic, or heteroaromatic aldehyde or mixtures thereof. The polybenzimidazole may have an intrinsic viscosity of at least 0.40 dl/g.