How to understand the "elasticity" and "plasticity" of thermoplastic elastomers? Thermoplastic elastomers are the third generation of rubber products after natural rubber and synthetic rubber. Its products not only have the traditional cross-linked chemical rubber with high elasticity, aging resistance, oil resistance and other properties, but also the plastic has plasticity and is easy to shape and process. Therefore, thermoplastic elastomer material has become a new material to replace traditional rubber.

So why do these materials have the high elasticity of traditional vulcanized rubber? Unlike traditional rubber molding methods, can it be molded and overmolded like plastic? The structural features of thermoplastic elastomer polymer macromolecular chains consist of resin segments (hard segments) and rubber segments (soft segments) with different chemical compositions. The inter-segment force of the hard segment is sufficient to form a physical "cross-link", the soft segment is a highly elastic segment with greater free rotation capability, and the soft and hard segments are arranged in the proper order and connected in the proper manner

This physical cross-linking of the hard segment is reversible, that is, it loses its ability to constrain macromolecular composition at high temperatures and exhibits plasticity, and when the temperature is lowered to room temperature, these "cross-links" recover again, and It acts as a cross-linking point for vulcanized rubber. In contrast to conventional vulcanizates, the hard segments of thermoplastic elastomers are the vulcanization crosslinks in the rubber. Therefore, it is precisely because of the structural characteristics and cross-linking state of this polymer chain that thermoplastic elastomers can exhibit the physical and mechanical properties of vulcanized rubber at room temperature, such as elasticity, strength and deformation characteristics, and can replace general vulcanized rubber to ensure rubber products.

In addition to the high elasticity of rubber, thermoplastic elastomers have the plasticity of ordinary plastics because at high temperatures, the hard segments in the molecular structure will soften or melt and become a melt. When an external force is applied, it will exhibit plastic flow, which indicates the processing properties of thermoplastics, and thus can be processed by conventional plastic molding methods. In addition, thermoplastic elastomers can also be overmolded, which is fundamentally different from thermoset elastomer rubbers

Therefore, for thermoplastic elastomers, "elastic" means that the material can show the high elasticity of rubber in the temperature range of use, and "plastic" means that it can be plasticized and flowed like plastic under processing conditions and secondary processing, It is because of the combination of high elasticity and plasticity that thermoplastic elastomers are widely used in sports, outdoor and other fields