Spandex is a polyurethane fiber, also known as elastic fiber because of its excellent elasticity, because of its unparalleled elasticity, it has been widely used in elastic clothing fabrics, and there is even a saying that no ammonia is not a cloth. So do you know what is the reason for the good elasticity of spandex fiber?
The main reason is that spandex is a polymer compound, and the performance of polymer materials is determined by its structure, in which the polymer structure includes a single molecular structure and the aggregate state structure of multiple molecules.
In terms of the microstructure of spandex single macromolecules, the spandex macromolecular chain is a linear block copolymer composed of polyether (soft segment) alternately with urethane, isocyanate and urea bond (hard chain segment). The soft segments can be retracted and connected by the hard segments, and the alternation of the soft and hard segments is equivalent to forming a series of small springs.
In the aggregate structure of spandex multiple molecules, its hard chain segment is easily crystallized urethane and urea structure, and the imino and carbonyl groups between the molecular chains can form strong hydrogen bond bonding. The soft chain segment can move freely after being stressed at room temperature, and the force between the molecular chains is very weak. After the hard section is stretched and oriented, a crystalline entanglement is formed, and the soft section can be moved like a spring, which is equivalent to weaving many small springs into a fishing net, which has both elasticity and elasticity, and can use the crystalline node of the hard section to pull back and shrink.
Therefore, the spandex yarn formed by the spring-like fishing net structure has its unparalleled ultra-high elasticity. Spandex woven into clothing can perfectly reflect the natural beauty of the human body.