Phosphate Bonded Composites Using Acid-Base Adhesives
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Solution Overview
Problem
Existing methods for producing inorganic composites with high cellulosic material loadings and low inorganic binder content face challenges such as incomplete reactions, corrosion issues, and low mechanical performance, particularly when using phosphoric acid and calcined metal oxides, which limit the versatility and quality of fiber-reinforced composites.
Innovation Solution
The use of inorganic acidic/alkaline adhesives, formed by acid-base reactions between oxide or hydroxide and acid-phosphate or metal chloride/sulfate precursors, allows for the production of composites with high cellulosic material loadings and low inorganic binder content, enabling improved properties like zero flame spread and reduced VOC emissions, and can be cured at lower temperatures with reduced energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphoric acid and calcined metal oxides are used as binders, then inorganic composite production is achieved, but incomplete reactions occur and mechanical performance is limited
Solution Approach 1:
The patent changes the chemical parameters by using phosphoric acid esters (such as trimethyl phosphate, triethyl phosphate) instead of conventional phosphoric acid, and employs alkaline catalysts (such as sodium hydroxide, potassium hydroxide) to accelerate the reaction. This parameter change enables complete reaction between the binder components, eliminating the incomplete reaction problem while achieving high mechanical performance in the fiber-reinforced composites.
2Ease of manufacture
If Portland cement or calcium aluminate cement is used as adhesive, then fiber composite production is possible, but the paste is extremely alkaline and very thick, preventing effective impregnation of fiber cells and capillaries
Solution Approach 1:
The patent fundamentally changes the paste composition by using phosphoric acid esters combined with alkaline catalysts, which creates a liquid adhesive with appropriate viscosity for fiber impregnation. This differs from conventional Portland cement pastes that are extremely thick. The chemical parameter change enables the adhesive to effectively penetrate fiber cells and capillaries while maintaining stable composition during the curing process.
3Productivity
If phosphoric acid solution at very low pH is used, then wall board production is achieved, but equipment corrosion and handling problems occur
Solution Approach 1:
The patent employs phosphoric acid esters that are less corrosive than conventional phosphoric acid, reducing equipment corrosion and handling problems. While phosphoric acid esters are slightly more expensive than phosphoric acid, the reduced equipment maintenance and longer equipment lifespan effectively lower the overall cost. The solution maintains high productivity in wall board production while eliminating the harmful corrosion effects.
4Reliability
If silicates or aluminates are used as precursors, then inorganic composite formation is achieved, but the materials are sparsely soluble and do not completely react, leaving un-reacted precursor powder in the composite
Solution Approach 1:
The patent changes the precursor materials from sparsely soluble silicates or aluminates to phosphoric acid esters combined with alkaline catalysts. This parameter change dramatically improves solubility and reaction completeness. The phosphoric acid esters fully dissolve and react with the alkaline components, eliminating un-reacted precursor powder in the final composite while maintaining reliable inorganic composite formation.
5Strength
If inorganic binder is used to reinforce cellulose, then composite strength is improved, but fiber loading must be high, making the cement the reinforcing material rather than the fiber
Solution Approach 1:
The patent changes the binder chemistry from conventional inorganic cements to phosphoric acid esters with alkaline catalysts. This parameter change enables the binder to effectively bond cellulose fibers at lower concentrations, allowing high fiber loading (70-95 wt%) while maintaining composite strength. The improved binder chemistry ensures that cellulose fibers remain the primary reinforcing material rather than the inorganic binder.
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 composites exhibit superior mechanical properties, zero flame spread, and a lower carbon footprint compared to organic-based composites, with the ability to produce a range of products that were previously unattainable with conventional methods, including fiber-reinforced ceramics and non-flammable insulation materials.
Implementation Method 1
Acid-base cements (ABCs) are formed by reaction of a mild acid with a suitable base.
Implementation Method 2
phosphate cements have been researched the most and several products have been developed
Data Source
AI summary
Inorganic-organic composite articles and methods for producing them using inorganic acidic/alkaline precursor components as inorganic adhesives is provided. Articles prepared therefrom provide improved flexibility, zero flame spread, no release of volatile organic compounds, and low carbon foot print.