Firstly, the softness of silicone is determined by its molecular structure. In silicone polymers, silicon atoms and oxygen atoms are arranged alternately, with methyl groups in polyorganosiloxanes oriented in a specific direction and featuring a large intermolecular spacing. This configuration allows for almost zero free energy for each silicon atom and its attached groups to rotate around the silicone-oxygen chain, enabling free rotation. Moreover, the carbon-methyl groups on the silicon atoms, while rotating freely, can almost completely shield the silicone-oxygen chain. The non-polar methyl groups reduce intermolecular forces between the chains, thereby imparting softness to fibers after silicone finishing.

Secondly, the oxygen atoms in the silicone structure can also adsorb onto the fiber surface. The bond angle of the silicone-oxygen bond can change under external forces and revert to its original state once the force is removed, allowing the chain to contract and confer elasticity to the fibers after finishing. This structural characteristic of silicone oxane makes silicone finishing agents the most superior fabric softening agents.

Lastly, among various silicone softeners, amino silicone oil exhibits the most pronounced softening effect. It is believed that the polar amino groups in amino silicone oil can more effectively bond with the fabric surface, enabling amino-modified polysiloxanes to firmly orient and adsorb onto fibers. This reduces the static friction coefficient of the fibers, allowing them to slide against each other with minimal force, thereby imparting enhanced smoothness to the fabric.