Polyamide Stabilization via Covalent Polyhydric Alcohol Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyamide compositions used in various applications, such as motor vehicle parts, face instability under heat, light, and inclement weather, leading to degradation and loss of mechanical properties, and existing stabilization methods are either ineffective or costly, especially when polyhydric alcohols are added post-polymerization, which can lead to additional processing issues and reduced performance over time.
Innovation Solution
Incorporating a polyhydric alcohol, particularly one with aliphatic carbons, during the polyamide polymerization process to form covalent bonds within the polyamide chains, enhancing stability and preventing the 'washing' or extraction of the alcohol, thus providing improved heat, light, and weather resistance without the need for additional stabilization steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyhydric alcohol is added to polyamide as a mixture during extrusion, then heat stabilization is improved, but additional processing steps are required and the alcohol is readily extractable over time
Solution Approach 1:
The patent combines the polyhydric alcohol with polyamide monomers before polymerization, merging the stabilizer incorporation step with the polymerization process itself. This eliminates the need for separate extrusion and stabilization steps, resolving the contradiction between heat stabilization and processing complexity
Solution Approach 2:
The polyhydric alcohol is incorporated into the polyamide structure during polymerization rather than added afterward. This preliminary action ensures the alcohol is covalently bonded to the polymer chains before the product is formed, preventing extraction and eliminating subsequent processing steps
2Ease of operation
If polyhydric alcohol is added during polyamide synthesis, then melt fluidity is improved, but heat stabilization performance decreases due to ester function formation
Solution Approach 1:
The patent changes the timing parameter of alcohol incorporation from post-polymerization to during polymerization. This parameter change allows the alcohol to react with monomers rather than forming ester functions with end groups, simultaneously improving melt fluidity and maintaining heat stabilization performance
3Reliability
If polyhydric alcohol is added as a mixture via extrusion, then heat stabilization is achieved, but the alcohol is readily extractable leading to performance decrease
Solution Approach 1:
The polyhydric alcohol is incorporated into the polyamide structure during polymerization rather than added afterward. This preliminary action ensures the alcohol is covalently bonded to the polymer chains before the product is formed, preventing extraction and eliminating subsequent processing steps
Solution Approach 2:
The patent creates a permanent copy of the stabilizing function by incorporating the polyhydric alcohol into the polymer structure itself. The alcohol becomes an integral part of the polyamide chains, ensuring long-term stability without extraction or degradation of performance over time
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 modified polyamide exhibits superior stability and retention of mechanical properties over time, even at high temperatures, with improved distribution and retention of the polyhydric alcohol, reducing the need for excessive additive amounts and minimizing equipment fouling, while maintaining adequate rheological and mechanical properties.
Implementation Method 1
the polyhydric alcohol may be found covalently bonded to the polyamide chains either by reaction with the end groups of carboxylic acid type or by reaction with the intracatenary amides
Implementation Method 2
the polyhydric alcohol may be found covalently bonded to the polyamide chains either by reaction with the end groups of carboxylic acid type or by reaction with the intracatenary amides
Data Source
AI summary
The present invention relates to the use of a polyhydric alcohol in a polyamide polymerization process for giving the modified polyamide obtained increased stability toward heat, light and/or bad weather. The invention also relates to a polyamide modified in this way, and also to polyamide compositions that may be used for the preparation of specific articles liable to be subjected to high temperatures.