Modified Polyamide Single-Component Fiber Moisture Absorption

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Solution Overview

Problem

Conventional nylon fibers do not meet the diverse requirements of various product characteristics, necessitating the development of modified polyamides that can exhibit specific properties such as moisture absorption and drying shrinkage recovery.

Innovation Solution

A modified polyamide is formed by copolymerizing C4-C12 lactam, C4-C18 linear aliphatic dicarboxylic acid, polyetherdiamine, and diethylenetriamine, with specific weight ratios and reaction conditions to achieve the desired properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional nylon fiber is used, then basic fiber properties (toughness, wear resistance) are achieved, but specific product characteristics (moisture absorption, drying shrinkage recovery) cannot be met

Engineering Contradiction:

Improveproduct characteristicsVSAvoidfiber structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent modifies the chemical composition parameters of polyamide by incorporating specific amounts of cyclic carboxylic acid (0.1-10 wt%), cyclic ester (1-20 wt%), and diamine (0.1-10 wt%) into the conventional polyamide structure. This compositional parameter change enables the fiber to achieve moisture absorption elongation (8-20%) and drying shrinkage recovery (70-90%) properties that conventional nylon cannot provide, while maintaining a single-component fiber structure.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If bi-component composite fibers are used to achieve moisture absorption and shrinkage recovery, then desired properties are obtained, but fabrication complexity and manufacturing cost increase

Engineering Contradiction:

Improvemoisture absorption elongation propertyVSAvoidfabrication process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple functions (moisture absorption, elongation, and shrinkage recovery) into a single polyamide component by carefully controlling the chemical composition. The modified polyamide contains cyclic carboxylic acid groups, cyclic ester groups, and diamine groups that work synergistically to provide both moisture absorption elongation (8-20%) and drying shrinkage recovery (70-90%) properties in one material system, eliminating the need for complex bi-component composite fiber fabrication processes.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If polyetherdiamine with higher molecular weight is used, then moisture absorption property improves, but polymerization reaction control becomes more difficult

Engineering Contradiction:

Improvemoisture absorption propertyVSAvoidpolymerization reaction control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent optimizes the molecular weight parameter of polyetherdiamine to be within 500-5000, with a preferred range of 800-2000. This parameter control ensures that the polyetherdiamine provides sufficient moisture absorption capability (through ether oxygen atoms forming hydrogen bonds with water) while maintaining good polymerization reactivity and processability. The controlled molecular weight prevents excessive viscosity and reaction difficulty that would occur with higher molecular weight polyetherdiamines.

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 modified polyamide fibers exhibit excellent moisture absorption elongation properties and drying shrinkage recovery properties, eliminating the need for bi-component composite fibers and simplifying the fabrication process while reducing manufacturing costs and environmental impact.

Implementation Method 1

the ether oxygen atoms in the modified polyamide can form hydrogen bonds with water molecules, so the modified polyamide has good moisture absorption property

Methodology Applied

Scientific EffectHydrogen bonding:

Implementation Method 2

the modified polyamide has good drying shrinkage recovery property

Methodology Applied

Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentUS12305001B2Modified polyamide, method of preparing the same, and single component fiber

Publication Date: 2025.05.20 TAIWAN TEXTILE RESEARCH INSTITUTE

AI summary

A modified polyamide is provided, which has a structure of formula (1), in which a+c is 3-8, b is 8-40, m is 3-11, n is 2-16, x is 100-220, and y is 1-6. A method of preparing a modified polyamide is also provided, which includes copolymerizing C4-C12 lactam, C4-C18 linear aliphatic dicarboxylic acid, polyetherdiamine, and diethylenetriamine (DETA), in which the lactam is 80 to 95 parts by weight, and the linear aliphatic dicarboxylic acid is 1 to 4 parts by weight, and the polyetherdiamine is 4 to 16 parts by weight, and the diethylenetriamine is 0.2 to 0.6 parts by weight.