Chemical and Physical Properties
Typical COC material will have a higher modulus than HDPE and PP, similar to PET or PC. COC also has a high moisture barrier for a clear polymer along with a low moisture absorption rate. In medical and analytical applications, COC is noted to be a high purity product with low extractables. COC is also a halogen-free and BPA-free product. Some grades of COC have shown a lack of estrogenic activity.
The optical properties of COC are exceptional, and in many ways very similar to glass. COC materials offer exceptional transparency, low birefringence, high Abbe number and high heat resistance. The moisture insensitivity of COC is often an advantage over competing materials such as polycarbonate and acrylics. The high flow of COC enables higher aspect ratio (large yet thin) optical component fabrication than other optical polymers. High ultraviolet transmission is a hallmark of COC materials, with optimized grades the leading polymer alternatives to quartz glass in analytical and diagnostic applications.
Some properties will vary due to monomer content. These include glass transition temperature, viscosity, and stiffness. The glass transition temperature of these polymers can exceed 200°C. COC resins are commonly supplied in pellet form and are suited to standard polymer processing techniques such as single and twin screw extrusion, injection molding, injection blow molding and stretch blow molding (ISBM), compression molding, extrusion coating, biaxial orientation, thermoforming and many others. COC is noted for high dimensional stability with little change seen after processing.
COC and COP are generally attacked by non-polar solvents, such as toluene. COC shows good chemical resistance and barrier to other solvents, such as alcohols, and is very resistant to attack from acids and bases.
Electronic properties of COC are in some respects similar to fluoropolymers, most notably a similarly low dissipation factor or tan delta, and low permittivity. It is a very good insulator.
Read more about this topic: Cyclic Olefin Copolymer
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