What are the properties of medical silicone hose?

At present, in the medical silica gel industry, silica gel hose is commonly used for liquid transmission, peristaltic pump and irrigation operation. The advantages and limitations of silicone hoses and the variables to be considered will be discussed through the material properties of various hoses.

Organic silica gel is the commercial name of many silica gel products, but most products are made of polydimethylsiloxane (PDMS). These polymers are characterized by high valence bond strength, resistance to chain break (organosilicon) and ultraviolet (UV) stability; It also has thermal stability and chemical stability, so it is easy to sterilize). Its polar main chain is prone to heterocleavage, but the methyl group on the chain can provide protection.

Therefore, silicone is hydrophobic, and the contact angle of water on the surface of polydimethylsiloxane (PDMS) model is high, which is 108 °. Due to this hydrophobicity, silicone does not react with aqueous medium in the absence of surfactant, and only reacts in strong alkali or weak acid environment.

The hose is packaged and supplied after extrusion. It is generally 50 foot coil type and is separately packed in double-layer sealed polyethylene bags. It is worth mentioning that because siloxanes are thermosetting, they cannot be reprocessed, just like thermoplastics.

Appearance and mechanical properties

Compared with some organic thermoplastics, the transparency of silicone is described as "translucent". This result is because the silicone elastomer used to make the hose is composed of silicone polymer and amorphous silica. Because the two materials have different refractive indices and there is no specific mixing method to match them, all silicone tubes are translucent.

After curing, silicone elastomers show meaningful mechanical properties, including medium hardness and high elongation at break, but the tensile strength is lower than polyurethane (PU). Compared with polytetrafluoroethylene (PTFE), they have sticky surface and high friction coefficient, but their rigidity is much smaller. Because they are hydrophobic and excellent electrical insulators, they attract dust. Their operating temperature range is larger than that of polyvinyl chloride (PVC).