Aliphatic-Aromatic Polyester Elastomer Shape Memory
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Solution Overview
Problem
Current shape memory materials, 3D print wires, heat shrinkable sleeves, medical limb immobilization braces, heat shrinkable films, and elastic fibers face limitations such as inadequate low-temperature plasticity, non-degradability, poor fixation, and limited recyclability, which hinder their performance and environmental sustainability.
Innovation Solution
A polyester composition comprising specific aliphatic-aromatic copolymers with defined molecular weight ranges and ratios, combined with optional additives, is developed for applications like shape memory materials, 3D print wires, heat shrinkable sleeves, and medical limb immobilization braces, offering improved low-temperature plasticity, degradability, and recyclability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If crosslinked polymer materials are used for heat shrinkable sleeves, then shape recovery rate is improved, but degradability and recyclability deteriorate
Solution Approach 1:
The patent extracts the crosslinked polymer network structure from the heat shrinkable sleeve composition, replacing it with thermoplastic polyester elastomer that lacks permanent crosslinks. This removal of the crosslinked structure enables degradability while maintaining shape memory functionality through reversible physical interactions rather than permanent chemical bonds.
Solution Approach 2:
The patent changes the fundamental parameter of molecular connectivity from permanent crosslinked networks to reversible physical associations. By using thermoplastic polyester elastomers with specific glass transition temperatures and melt flow indices, the material exhibits shape memory behavior through reversible chain entanglement and crystallization rather than irreversible crosslinking, enabling both high shape recovery and degradability.
2Ease of operation
If TPU materials are used for 3D print wires, then flexibility is improved, but printing temperature increases
Solution Approach 1:
The patent changes the glass transition temperature parameter of the polyester elastomer to fall within -50°C to 0°C, which is significantly lower than conventional TPU materials. This parameter adjustment allows the material to remain flexible at room temperature while reducing the printing temperature requirement from 190-260°C to below 150°C, as the lower Tg enables chain mobility and deformation at reduced temperatures.
Solution Approach 2:
The patent employs composite polyester elastomer formulations combining different diols (butanediol, hexanediol, octanediol) and dicarboxylic acids (succinic acid, adipic acid, sebacic acid) to achieve the desired balance of flexibility and low printing temperature. This composite approach allows tuning of both mechanical properties and thermal behavior to meet the dual requirements of flexibility and low-temperature processability.
3Speed
If shape memory polymers with high deformation rate are developed, then maximum deformation rate is improved, but shape recovery rate and shape fixing rate deteriorate
Solution Approach 1:
The patent applies local quality by creating distinct molecular regions within the polyester elastomer: amorphous regions with low glass transition temperature that enable high deformation rate, and crystalline regions that provide shape fixing and recovery. The specific composition ratio and molecular architecture create localized soft segments for deformation and hard segments for structural stability, allowing simultaneous achievement of high deformation rate and reliable shape recovery.
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 polyester composition achieves high deformation and recovery rates, enhanced recyclability, and adjustable hardness with temperature, addressing the limitations of existing materials by providing flexible, degradable, and recyclable solutions for various applications.
Implementation Method 1
the glass transition temperature of the polyester composition is from -50° C. to 0° C.
Implementation Method 2
After undergoing the initial shaping, thermally stimulated shape memory material is deformed under an external force at a certain temperature, and can maintain the deformed shape after cooling; and after reheating, it can restore the original shape.
Implementation Method 3
In the aspect of heat shrinkable sleeves, at present, on the market, they are mainly prepared from irradiation crosslinked polyolefin materials, and can be restored to the original shape by heating after expansion and shaping.
Data Source
AI summary
A polyester composition includes a first polyester selected from one or more of aliphatic-aromatic copolyesters, which is a copolymer comprising repeating units A as shown in formula (I) and repeating units B as shown in formula (II), in which m is an integer of 2 to 10 and n is an integer of 2 to 8; p is an integer of 2 to 10; and m, n and p are the same or different from each other. Optionally, the polyester composition has a second polyester. The polyester composition includes at least two polyesters. The polyester composition can be used in shape memory materials, 3D print wires, heat shrinkable sleeves, functional layers, medical limb immobilization braces, heat shrinkable thin films, nonwoven fabrics, elastic fibers, etc.