Long-Chain Polyamide Composition Stabilizing Melt Rheology

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Solution Overview

Problem

The polyamide industry faces challenges in producing high-performance polyamides with long-chain α,ω-aminoalkanoic acids or esters, as they often result in unstable melt rheology at high temperatures, leading to increased viscosity and equipment blockages during processing.

Innovation Solution

A composition comprising long-chain α,ω-aminoalkanoic acid or ester combined with a specific content of alkanoic acid or ester, along with optional nitrile ester, secondary amine, and dimer, is used, with precise molar ratios and hydrogenation processes to achieve high degrees of polymerization and thermal stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If long-chain α,ω-aminoalkanoic acid or ester monomers are used to produce high-performance polyamides, then the degree of polymerization increases, but the melt rheology becomes unstable at high temperatures causing increased viscosity

Engineering Contradiction:
Improvedegree of polymerizationVSAvoidmelt rheology stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The invention changes the chemical composition parameters of the monomer by introducing a specific impurity profile (alkanoic acid/ester at 0.01-0.5% and hydroxy acid at 0.01-0.1%) into the long-chain α,ω-aminoalkanoic acid/ester. This parameter modification stabilizes the melt rheology at high temperatures while maintaining high degree of polymerization, resolving the contradiction between achieving high molecular weight and maintaining processing stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite monomer system combining the main long-chain α,ω-aminoalkanoic acid/ester with specific impurity components (alkanoic acid/ester and hydroxy acid) in controlled amounts. This composite approach leverages the stabilizing effect of the impurity components to maintain melt rheology stability while the primary monomer provides the high degree of polymerization needed for high-performance polyamide production.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If long-chain α,ω-aminoalkanoic acid or ester monomers are used to achieve high degrees of polymerization, then polyamide performance improves, but equipment blockages occur during processing due to excessive viscosity

Engineering Contradiction:
Improvedegree of polymerizationVSAvoidequipment blockage
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention modifies the monomer composition parameters by controlling the content of alkanoic acid/ester (0.01-0.5%) and hydroxy acid (0.01-0.1%) to optimize the balance between achieving high degree of polymerization and maintaining acceptable melt viscosity during processing, thereby preventing equipment blockages while preserving polyamide performance.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If monomers of high purity are used for polymerization, then high degrees of polymerization are achieved, but the melt viscosity increases excessively leading to processing difficulties

Engineering Contradiction:
Improvedegree of polymerizationVSAvoidprocessing ease
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention optimizes the purity parameters by introducing specific controlled impurities (alkanoic acid/ester at 0.01-0.5% and hydroxy acid at 0.01-0.1%) that actually improve processing ease by stabilizing melt rheology, while maintaining high degree of polymerization. This counterintuitive approach shows that absolute purity is not always beneficial for processing.

Inventive Principle:
Principle #35Parameter changes

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 solution enables the production of long-chain polyamides with high degrees of polymerization and stable melt rheology at high temperatures, preventing equipment blockages and improving processing efficiency.

Implementation Method 1

processes for hydrogenation of unsaturated acid nitriles or unsaturated nitrile esters

Methodology Applied
Scientific EffectHydrogenation: Hydrogenation

Data Source

PatentUS10683258B2Composition made of amino acid or ester with polymer quality and methods for obtaining same
Publication Date: 2020.06.16 ARKEMA FRANCE SA

AI summary

The present invention relates to a composition which comprises at least one α,ω-amino-alkanoic acid or ester and at least one alkanoic ester or acid, characterised in that: the α,ω-amino-alkanoic acid or ester has formula H2N—(CH2)n-COOR, wherein n=9 to 13 and R is an alkyl group or a hydrogen; the alkanoic ester or acid has formula R1—COOR2, wherein R1 is a straight or branched alkyl group with formula CmH2m+1 or CmH2m−3, wherein m=6 to 20 and R2 is an alkyl group or a hydrogen; the molar ratio between the alkanoic acid(s) or ester(s) and the α,ω-amino-alkanoic acid(s) or ester(s) is in the range from 0.001 to 0.4%. The present invention also relates to novel methods for obtaining such a composition.