Cyclic Olefin Copolymer
Encyclopedia
Cyclic Olefin Copolymer (COC) is an amorphous polymer made by several polymer manufacturers. COC is a relatively new class of polymers when compared to polypropylene
and polyethylene
. This material is primarily used in applications requiring glass-like clarity including lenses, vials, monitors, and medical devices.
) or 1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethanonaphthalene (tetracyclododecene) with ethene, TOPAS Advanced Polymer's TOPAS, Mitsui Chemical’s APEL, or by ring-opening metathesis polymerization of various cyclic monomers followed by hydrogenation (Japan Synthetic Rubber’s ARTON, Zeon Chemical’s Zeonex and Zeonor)." These later materials using a single type of monomer are more properly named cyclic olefin polymers (COP).
than HDPE and PP
. COC also has a high moisture barrier for a clear polymer along with a low absorption rate. In medical applications, COC is noted to be a high purity product with low extractables. COC is also a halogen-free product.
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 150 °C.
COCs and COPs are generally attacked by non-polar solvent
s, such as toluene
. COCs show good chemical resistance to other solvents.
Extrusion
COC can be extruded with both cast and blown film equipment. These films are then used in consumer applications including food and pharmaceutical packaging. Commercial structures of COC used in blister packs are typically coextruded with a thick COC core and thin polypropylene skin layers. PVC and PvDC can also be placed on the skins via lamination. Profile extrusion is another method that can be used to make COC reinforced tubes or pipes.
Molding
While there are many different types of molding, COC is primarily used in injection molding. Its natural clarity makes it useful in lenses for cameras, projectors and copiers. COC has little to no extractables which make it useful in diagnostic and medical devices. Most COC grades can also undergo sterilization by gamma radiation, steam, and ethylene oxide
.
Fiber Spinning
COC has unique electrical properties that resist dielectric
breakdown and have a very low dielectric loss over time. Because of this COC is used in filter media that require a charge retention to work properly.
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
and polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
. This material is primarily used in applications requiring glass-like clarity including lenses, vials, monitors, and medical devices.
Various types of COC
In 2005 there were "several types of commercial cyclic olefin copolymers based on different types of cyclic monomers and polymerization methods. Cyclic olefin copolymers are produced by chain copolymerization of cyclic monomers such as 8,9,10-trinorborn-2-ene (norborneneNorbornene
Norbornene or norbornylene or norcamphene is a bridged cyclic hydrocarbon. It is a white solid with a pungent sour odor. The molecule consists of a cyclohexene ring bridged with a methylene group in the para position...
) or 1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethanonaphthalene (tetracyclododecene) with ethene, TOPAS Advanced Polymer's TOPAS, Mitsui Chemical’s APEL, or by ring-opening metathesis polymerization of various cyclic monomers followed by hydrogenation (Japan Synthetic Rubber’s ARTON, Zeon Chemical’s Zeonex and Zeonor)." These later materials using a single type of monomer are more properly named cyclic olefin polymers (COP).
Chemical and physical properties
COCs have a transparency similar to glass in its natural form. Typical COC material will have a higher modulusElastic modulus
An elastic modulus, or modulus of elasticity, is the mathematical description of an object or substance's tendency to be deformed elastically when a force is applied to it...
than HDPE and PP
PP
PP, pp, Pp, or Pp may refer to:- Places :* Perry Park, any of several places in Australia, England, or the United States* Phi Phi Islands, in Thailand* Phnom Penh, the capital city of Cambodia...
. COC also has a high moisture barrier for a clear polymer along with a low absorption rate. In medical applications, COC is noted to be a high purity product with low extractables. COC is also a halogen-free product.
Some properties will vary due to monomer content. These include glass transition temperature, viscosity
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
, and stiffness
Stiffness
Stiffness is the resistance of an elastic body to deformation by an applied force along a given degree of freedom when a set of loading points and boundary conditions are prescribed on the elastic body.-Calculations:...
. The glass transition temperature of these polymers can exceed 150 °C.
COCs and COPs are generally attacked by non-polar solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
s, such as toluene
Toluene
Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...
. COCs show good chemical resistance to other solvents.
ExtrusionPlastics extrusionPlastics extrusion is a high volume manufacturing process in which raw plastic material is melted and formed into a continuous profile. Extrusion produces items such as pipe/tubing, weather stripping, fence, deck railing, window frames, adhesive tape and wire insulation.-Process:In the extrusion of...
COC can be extruded with both cast and blown film equipment. These films are then used in consumer applications including food and pharmaceutical packaging. Commercial structures of COC used in blister packs are typically coextruded with a thick COC core and thin polypropylene skin layers. PVC and PvDC can also be placed on the skins via lamination. Profile extrusion is another method that can be used to make COC reinforced tubes or pipes.MoldingMolding (process)Molding or moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a pattern....
While there are many different types of molding, COC is primarily used in injection molding. Its natural clarity makes it useful in lenses for cameras, projectors and copiers. COC has little to no extractables which make it useful in diagnostic and medical devices. Most COC grades can also undergo sterilization by gamma radiation, steam, and ethylene oxideEthylene oxide
Ethylene oxide, also called oxirane, is the organic compound with the formula . It is a cyclic ether. This means that it is composed of two alkyl groups attached to an oxygen atom in a cyclic shape . This colorless flammable gas with a faintly sweet odor is the simplest epoxide, a three-membered...
.
Fiber SpinningFiberFiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....
COC has unique electrical properties that resist dielectricDielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
breakdown and have a very low dielectric loss over time. Because of this COC is used in filter media that require a charge retention to work properly.