Co-polyester Polyols for Spandex via 2-Methyl-1,4-Butanediol
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Solution Overview
Problem
Current polyester glycols used in spandex fiber production face limitations in hydrolytic stability and mechanical properties, making them unsuitable for demanding applications, and the high cost of certain building blocks restricts their commercial use.
Innovation Solution
The development of co-polyester polyols and glycols derived from a mixture of 2-methyl-1,4-butanediol and 1,4-butanediol, which are used to produce poly(urethane urea) compositions and spandex fibers through a process involving reaction with diisocyanate and diamine chain extenders, offering improved mechanical and dynamic performances at lower costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyester glycols are used in spandex fiber production, then mechanical properties and hydrolytic stability are improved, but manufacturing cost increases due to expensive building blocks
Solution Approach 1:
The patent changes the chemical composition parameters of the glycol by using a mixture of 2-methyl-1,4-butanediol and 1,4-butanediol in specific ratios (5-50 wt% 2-methyl-1,4-butanediol). This parameter change achieves improved hydrolytic stability comparable to hindered glycols while using cheaper building blocks, thereby resolving the contradiction between reliability and manufacturing cost
Solution Approach 2:
The patent creates a composite glycol system by combining 2-methyl-1,4-butanediol and 1,4-butanediol in specific proportions. This composite approach provides synergistic effects where the mixture achieves the hydrolytic stability of expensive hindered glycols while maintaining cost-effectiveness, resolving the technical contradiction
2Reliability
If polyester glycols are used in spandex fiber production, then hydrolytic stability is improved, but mechanical properties deteriorate
Solution Approach 1:
The patent optimizes the compositional parameters of the glycol mixture and controls molecular weight (1,000-4,000 g/mol) and intrinsic viscosity (0.08-0.40 dL/g) to achieve a balance where both hydrolytic stability and mechanical properties are improved simultaneously, resolving the contradiction between these two features
3Ease of manufacture
If traditional polyester glycols are used, then processing is simplified, but low-temperature flexibility and dynamic properties are insufficient
Solution Approach 1:
The patent modifies the glycol structure by incorporating 2-methyl-1,4-butanediol which introduces branching that reduces crystallinity and lowers melting point. This parameter change maintains processability while significantly improving low-temperature flexibility and dynamic properties such as recovery forces, resolving the contradiction between ease of manufacture and adaptability
4Reliability
If spandex fibers are made with improved mechanical properties, then durability increases, but manufacturing cost increases
Solution Approach 1:
The patent uses cheaper building blocks (2-methyl-1,4-butanediol and 1,4-butanediol mixture) instead of expensive hindered glycols to produce spandex fibers with improved durability. This substitution of cheaper materials achieves the same or better performance at lower cost, resolving the contradiction between durability and manufacturing cost
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 spandex fibers exhibit enhanced mechanical and dynamic properties, improved low-temperature flexibility, and reduced crystallinity, making them suitable for textile and personal care applications while being more cost-effective than traditional methods.
Implementation Method 1
reacting the polyester glycol with a diisocyanate yielding a capped glycol, then chain extending the resulting capped glycol with a diamine
Data Source
AI summary
Co-polyester glycols and polyurethanes and poly(urethane ureas) derived from mixtures containing 2-methyl-1,4-butanediol, articles of manufacture thereof and methods for their production and use are provided.