Common medical rubber materials and uses

At present, there are many rubber materials for medical varieties, including natural rubber and various synthetic rubbers, among which silicone rubber and butyl rubber are the most widely used and studied.

Natural rubber

Natural rubber is the first medical elastomer used. Because it contains a highly sensitizing vegetable protein, the compounding agent N-nitrosamine used in the human body has a large stimulating reaction, and can only be used in the human body after being purified and modified.

The purification of natural rubber mainly uses deacidification protein purification. The purified natural rubber needs to be selected from a suitable vulcanization system, such as vulcanization with an organic peroxide or radiation vulcanization to produce a desired rubber article. Natural rubber has excellent elasticity and is widely used in various kinds of medical products such as tubes, belts, plugs, gloves and condoms. However, it has poor resistance to biological aging and is generally used for in vitro medical rubber products.

Polyurethane

Polyurethane is a kind of polymer material between rubber and plastic. It has high elasticity of rubber and high strength of plastic. It has a wide range of hardness, excellent wear resistance, biocompatibility, especially anticoagulant, and is often used as a blood pump material for artificial heart.

Depending on the hard segment of the material structure, polyurethane can be divided into three generations. The first generation uses aromatic diisocyanate as the hard segment, the second generation uses the aliphatic isocyanate as the hard segment, and the third generation is based on the biodegradable elastomer. segment. At present, the third-generation materials are in the research and development stage and have not yet been industrialized, but their application prospects are quite extensive.

At present, domestic medical polyurethanes are less industrialized, and many units have conducted research on medical polyurethanes, such as Shanxi Research Institute of Chemical Industry, Zhongshan University, Shanghai Rubber Products Research Institute, and Jiangsu Chemical Industry Research Institute. Some thermoplastic medical polyurethane films have been developed. Some products such as body temperature shape memory polyurethane have been industrialized.

Silicone Rubber

The silicone rubber polymer is composed of a Si-O-Si bond, and its helical structure cancels the polarities of the silicon-oxygen bonds, and the side chains are generally low-polar or non-polar groups, so the entire macromolecule Very low in nature, making silicone rubber exhibit hydrophobicity, oxidation resistance and aging resistance. In addition, the Si-O bond in the main chain and the Si-C bond in the side chain are similar to the ionic bond, and do not undergo cracking, oxidation, etc. at normal use temperature (below 250 ° C), so they are excellent. Heat resistance.

Because of its physiological inertness, non-toxicity, non-adhesive ability with other materials, it can withstand many characteristics such as cooking and disinfection, and can be widely used in medical and health care. Due to the small intermolecular force of silicone rubber, its film has better gas permeability than ordinary rubber and plastic waxing film, and has strong selectivity to different air permeability. Therefore, it can be used as a gas exchange film medical product and body. Artificial organs, etc.