Meaning
Chemical byproducts formed during the synthesis of cyclic olefin copolymers can remain trapped within the polymer matrix. Plastic molders monitor norbornene dimers because these volatile compounds can affect the optical and sensory properties of molded parts. These cyclic compounds originate from the thermal reaction of norbornene monomers during polymerization.
Their presence must be minimized to maintain material purity.
Optical Quality
High clarity makes cyclic olefin copolymers ideal for medical syringes and optical lenses. The accumulation of norbornene dimers within the molded parts can cause slight yellowing or cloudiness under intense light exposure. Processors must use high-purity resin grades to avoid these optical failures.
Sensory Impact
Volatile organic compounds can migrate from plastic packaging into sensitive food or pharmaceutical products. The release of norbornene dimers often imparts an unpleasant chemical odor or taste to the packaged substance. This migration must be controlled to prevent product contamination and regulatory rejection.
Minimizing these residues is a priority for packaging manufacturers who produce high-barrier films and containers. The compound’s presence in trace amounts can ruin entire batches of liquid medicine.
Extraction Method
Removing trace volatile compounds from molded parts prevents post-molding outgassing. Thermal vacuum extraction or extended purging processes help drive out norbornene dimers from the polymer matrix after injection molding. This step is performed before the components are assembled into sterile medical devices.
Controlled degassing ensures that the parts remain odor-free and compliant.
