Views: 0 Author: Site Editor Publish Time: 2021-11-23 Origin: Site
Silicone hose is hydrophobic and is an excellent electrical insulator
Silicone is the commercial name for many products, but most are made of polydimethylsiloxane (PDMS). These polymers are characterized by high covalent bond strength and resistance to homolytic chain scission (silicone has ultraviolet (UV) stability; it also has thermal and chemical stability, so it is easy to sterilize). The polar main chain is prone to scission and chain scission, but the methyl group on the chain can provide protection.
Therefore, silicone is hydrophobic, and the contact angle of water on the surface of the polydimethylsiloxane (PDMS) model is relatively high, 108°. Due to this hydrophobicity, in the absence of surfactants, silicone does not react with the aqueous medium, and only reacts in a strong alkali or strong acid environment.
The hose is packaged and supplied after being extruded, usually in a 50-foot coil type, separately packed in a double-sealed polyethylene bag. It is worth mentioning that, due to the thermosetting properties of siloxanes, they cannot be reprocessed like thermoplastics. For the same reason, they cannot be heat-sealed; therefore, when connecting, the silicone hose is sleeved on the hose barb joint, and the hose is fastened with two ties from opposite directions to secure the hose. Co-molding compression molding is feasible, and is sometimes used in the field of medical devices.
Appearance and mechanical properties of silicone hose
Compared with some organic thermoplastics, the transparency of silicone is best described as "translucent". This result is because the silicone elastomer used to make the hose is composed of silicone polymer and amorphous silica. Since these two materials have different refractive indices and there is no specific mixing method to match them, all silicone hoses are translucent.
After the silicone hose is cured, the silicone elastomer exhibits meaningful mechanical properties, which include medium hardness and high elongation at break, but the tensile strength is lower than that of polyurethane (PU). Compared with polytetrafluoroethylene (PTFE), they have a sticky surface and a higher coefficient of friction, but are much less rigid. Because they are hydrophobic and are excellent electrical insulators, they attract dust. Their operating temperature range is greater than that of polyvinyl chloride (PVC).