The present invention discloses a crack resistant high mechanical strength halogen-free flame retardant thermoplastic polyurethane elastomer and its preparation method, which is prepared by weight of the following components: 45-65 parts of thermoplastic polyurethane elastomer, 20-45 parts of flame retardant, 0.3-2 parts of terminating agent, 0.5-4 parts of chain extender, 1-2 parts of antioxidant, and 0.5-2 parts of other additives. The present invention introduces a terminating agent at the front end of the twin-screw extruder through a step-by-step method to seal the TPU, avoiding its reaction with the chain extender introduced at the back end, thereby reducing the molecular weight of the TPU in this part; The TPU introduced in the backend reacts with the chain extender to expand the chain, resulting in an increase in its molecular weight. This forms two peaks (bimodal) with different molecular weight distributions, thereby improving the extrusion processing performance of cables and other materials, enabling better fusion of the "mold line", and avoiding potential risks of cable outer sheath cracking caused by poor material flow fusion.
Country Code: CN
Application Number: CN202311795742.3
