Why vulcanizing agent is needed for rubber products production？

The purpose of adding vulcanizing agent is to make the ingredients produce chemical reaction, that is to say, between the rubber molecules to produce bridging (cross linking) phenomenon and change the physical properties of rubber. The chemical bridging effect makes the rubber ingredients from soft, sticky thermoplastic body into a strong thermosetting material, which is less affected by the temperature. So far, sulfur is still the most widely used rubber vulcanizing agent. Other sulfur-carrying agents (sulfur donor) such as TMTD (TUEX) is also sometimes used as a total or partial replacement of elemental sulfur in low-sulfur or non-sulfur sulfur vulcanizing system formulations, so that products can improve their heat resistance. The selection and dosage of the sulfur donor are also important in the main formulation.