Medical polymers can be defined as polymers used in the healthcare sector for medicinal purposes. Medical polymers must be stabilizability, processability, biocompatibility, fluid compatibility, and other mechanical properties that suit their specific application.

There are three major types of sterilization methods considered in the selection of medical polymers. These are autoclave (heat, steam, and pressure), gamma irradiation, and ethylene oxide. Sterilization is majorly used in polymer selection. Solvent, hydrolytic, and radiation resistance are utilized in all three methods.

In 2021, the medical polymer industry contributes $17,842.5 million, and it is projected to generate $36,035.3 million in revenue in 2030, advancing at a rate of 8.1%, led by the expansion of the pharmaceutical industry, along with worldwide rising expenditure on healthcare.

Types of Medical Polymers

Commodity Polymers

The foremost option for original equipment manufacturers is to determine if commodity polymers meet the application requirements, such as polyvinyl chloride, polypropylene, acrylonitrile butadiene styrene terpolymers, polyethylene, and polyesters. Their major applications include simple fluid containers, equipment housings, gown materials, masks, and tubing.

Polyvinyl chloride is inexpensive and transparent. It possesses balanced mechanical properties. In PP, it substitutes methyl group with chlorine. Plasticizers are required for acceptable processing conditions.

Moreover, the acrylonitrile butadiene styrene or ABS polymers possess complementing mechanical properties to solvent resistance due to three monomers properties. ABS is placed at the commodity engineering polymers and polyethylene terephthalate intersection.

Engineering Polymers 

In the case of engineering polymers, the raw engineering resins are polybutylene terephthalate, polycarbonate, polypropylene oxide, aliphatic polyketones, and select polyamides (nylon 46). All of these polymers possess a high degree of thermal, wear, solvent, and electrical resistance as well as higher glass transition temperatures and melting points compared to commodity resins.

Step growth polymerization is widely used commercially by polyesters, polycarbonate, and polyamides in engineering thermoplastics. These are polymerized through diacids and diamines, diacids and diols, and bisphenol and phosgene. These polymers and their blends are utilized in the application of MD equipment housings, hemodialysis membrane housings, transparent medical packaging, and others.

Polyesters

In the case of polyesters, polyethylene, terephthalate, and polybutylene terephthalate are widely used as medical polymers. PET is highly adopted as skin-touching layers in POCT wearable sensors, and numerous other applications. PBT is highly flexible, as it has double the number of carbons in its backbone, which causes good stiffness, crystallinity, and strength. Moreover, these polyesters possess a higher melting point, and glass transition compared to PP and PE.

Polyamides

Nylon 6, and nylon 66, amide groups are widely used, among polyamides, due to their strong interchain hydrophilicity, and hydrogen bonding, coupled with high modulus, tensile strength, along with higher melting point. It enhances the stiffness and allows for higher temperature usage for internal device components.

Polycarbonates 

Polycarbonates possess higher aromaticity, with the absence of symmetry, which may lead to minimal transparency, crystallinity, and high glass transition, along with good dimensional stability. Such properties enable medical device applications. These polymers are widely used in fluid administration, and blood oxygenators applications in the form of intravenous connectors, controls, valves, catheters, stopcocks, and syringes. Alternations in the polycarbonate property enhance sterilization resistance, radiation sterilization resistance, and lipid resistance. In addition, polycarbonates are used as a crucial element in polymer blends with ABS, and PBT.

Silicones

Silicones are widely used in contact lenses, breast implants, medical tubing, and pacifiers. These polymers possess maximum oxygen permeability, electrical insulation, flexibility, transparency, and biocompatibility. Moreover, silicones are thermoset in nature and require liquid injection molding or cast molding. Silicones are polymerized through photo-initiated free radical polymerization and heat.

Therefore, medical polymers have high demand due to their vast healthcare applications.

Source: P&S Intelligence