Epoxide Composition Low-Temperature Curing Pipeline Rehabilitation
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Solution Overview
Problem
Existing epoxy-based compositions have a short pot life, leading to premature curing and viscosity increase, which limits their application in processes like pipe rehabilitation, and they often require high temperatures for curing, causing issues with adhesion and toxicity.
Innovation Solution
A curable epoxide-based composition comprising a phenyl glycidyl ether polyepoxide and a curing agent mixture of N-alkanol piperidine and N-cyclohexyl-N,N-dialkyl amine salts, which maintains a workable viscosity for up to 30 hours at ambient conditions and cures at temperatures below 80°C, allowing for extended processing time and improved adhesion to various substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a liquid epoxide component and a liquid curing agent component are used, then the composition can penetrate fiber bundles without filtration, but the pot life becomes short due to abrupt reaction
Solution Approach 1:
The patent changes the chemical parameters of the curing agent by using a mixed amine system (polyamide and polyaminolev) with specific molecular weights and functional group ratios. This parameter optimization controls the reaction kinetics to achieve both good penetration and extended pot life of 24-72 hours
Solution Approach 2:
The patent creates a composite curing agent system by combining two different amine types (polyamide and polyaminolev) in specific ratios. This composite approach allows the synergistic effect of both components to achieve extended pot life while maintaining liquid state and penetration capability
2Stability of the object's composition
If the composition is left standing for a long period, then the viscosity increases due to reaction, but the desired working procedure cannot be performed
Solution Approach 1:
The patent optimizes the chemical parameters including the ratio of primary to secondary amine groups (1:4 to 1:10), molecular weights of curing agents (500-5000 and 1000-10000), and epoxy equivalent weights (150-500). These parameter changes ensure viscosity remains stable within 2000-20000 cP for 24-72 hours at ambient temperature
3Productivity
If high temperature curing is used, then the curing speed increases, but adhesion and toxicity issues occur
Solution Approach 1:
The patent changes the curing temperature parameter from conventional high temperatures to a lower range of 20-80°C. This parameter change is achieved by selecting curing agents with appropriate activation energy characteristics, allowing slow curing at low temperatures without compromising adhesion or generating toxic emissions
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 composition achieves a long pot life of up to 30 hours with a viscosity suitable for application and spreading, cures effectively at low temperatures, and demonstrates excellent adhesion to concrete, steel, fiberglass, and PVC substrates, facilitating rehabilitation of buried pipes without the need for high temperatures or toxic chemicals.
Implementation Method 1
the initiation of curing is depending on the thermal fusion of two components
Implementation Method 2
a reaction can occur and the viscosity of the composition increases
Data Source
AI summary
An epoxide based composition that can be cured at a temperature of less than about 70 C is disclosed. The composition is a liquid at ambient conditions and, therefore, can be used to rehabilitate the interior surfaces of pipelines. The epoxide-based composition comprises at least one epoxide component (component A) and at least one curing agent component (component B) wherein(A) the epoxide component comprises a phenyl glycidyl ether polyepoxide; and(B) the curing agent component comprises a mixture of two salt compounds formed, respectively, from an N-alkanol piperidine and a carboxylic acid bearing 7-12 carbon atoms, and N-cyclohexyl-N,N-dialkyl amine and a carboxylic acid bearing 7-12 carbon atoms.