Types of medical polyurethane and the advantages and disadvantages?

Polyurethane for catheters are TPU.\x0d\Polyurethane thermoplastic elastomers in medical devices\x0d\Polyurethane elastomers are polymers with soft segments (long-chain polyols) and hard segments (diisocyanates and chain extender) block*** polymerization, through the adjustment of the ratio of these two chain segments, you can prepare polyurethane elastomers with different hardnesses, with hardnesses ranging from 60A-84D. The hardness range is 60A-84D. Due to the medical grade polyurethane elastomers require high purity, harsh reaction conditions and process conditions, the dosage is not large, the production technology is only concentrated in the hands of a few large foreign companies, such as: Lubrizol, Bayer, BASF, Dow Chemical and Huntsman. \x0d\ medical polyurethane elastomers have good elongation and anti-flexing properties, high strength, wear resistance, good biocompatibility, no teratogenic effect, no allergic reaction, blood compatibility, good anti-thrombotic properties, and does not damage the blood components, while polyurethane materials have excellent physical and mechanical properties and processing performance, so that it has been widely used in the field of medical care. In the 1950s, polyurethane elastomers began to be used in medical materials, initially for bone repair materials, and then successfully used in supplementary coatings for vascular surgery sutures. Polyurethane elastomers as a medical material received more and more attention, and a variety of medical polyurethane elastomers were rapidly developed. In the early 1980s, polyurethane elastomers were used to make artificial heart transplants with great success, which led to the further development of polyurethane elastomer materials in the biomedical field. At present, the medical products developed by applying polyurethane elastomers mainly include artificial heart assist devices, artificial blood vessels, and various catheters. \x0d\ artificial heart as well as cardiac assistive devices on the performance of the material is multi-faceted, clinical practice has proved that polyurethane elastomers in terms of blood compatibility, biocompatibility, durability and so on are better than other rubbers, and has become the first choice of materials for the development of artificial heart and its assistive devices at home and abroad. At present, several polyurethane elastomers for artificial heart have been commercialized such as Biomer, Cardiothane, Pellethane, TecoflexEG and so on. \x0d\ polyurethane elastomers good elasticity, blood compatibility and compliance with natural blood vessels become a good choice for the preparation of artificial blood vessels. The first TPU to be used in artificial blood vessels is Covita's polycarbonate-based polyurethane under the trade name Corethane. according to sources, a team of researchers at Rice University in the United States has produced a new type of polyurethane elastomer material that can be used to make small-diameter artificial blood vessels. Small diameter artificial blood vessels due to blood clotting or tissue blockage makes other materials can not help. \x0d\ Currently, the raw material used in most of the medical catheters in China is soft polyvinyl chloride (PVC), which is used in more than 100,000 tons/year in medical infusion devices, but the residual vinyl chloride monomer (VCM) in the material and DEHP, a plasticizer added to it, are both potentially hazardous to the human body.TPU's biological properties, mechanical properties, and processing properties are comparable to those of PVC, or even more superior, while being non-toxic, and not requiring the addition of additives for processing. It is also non-toxic and does not require the addition of additives for processing. Therefore, in terms of medical catheters, TPU from the theory of the possibility of replacing PVC, statistics show that only the United States every year 16,000 tons of polyurethane elastomers used in the production of medical catheters, a variety of catheter output value of more than 2 billion U.S. dollars. The world's annual sales of various catheters has reached billions of dollars. TPU's only shortcoming is that medical-grade TPU is expensive, and is currently mainly used in the development of high-value-added precision interventional catheters, such as: indwelling needle cannulae, central venous catheters, peripherally placed central venous catheters, electrophysiology catheters, imaging catheters, dilatation of the balloon catheter, microcatheters and so on. \x0d\ using thermoplastic polyurethane elastomers and soft polyvinyl chloride **** mixed resin, can be made into a variety of medical special infusion and transfusion devices, with polyurethane elastomers made of double-pressure hose of the inner rubber layer, can prevent the migration of plasticizers in the polyvinyl chloride to the solution. Blood bags produced with this material can effectively solve the problem of plasticizer migration that exists in blood bags made of separate PVC materials. \x0d\ In addition, polyurethane elastomers are also used as coating materials for tracheal cannulae, artificial limbs, prosthetics, birth control supplies, extracorporeal circulation blood lines, medical connecting lines and interventional consumables. \x0d\ in Europe and the United States developed countries, medical polyurethane elastomer materials have long been commercialized and new materials, new uses are still under continuous development, while in the country, this market has not yet been truly developed, many products have been relying on imports, and the gap with foreign countries is very large. There are media reports that the domestic demand for TPU will continue to grow at a rate of 20% per year. Therefore, in the domestic medical polyurethane elastomer material research is imminent.