Polynorbornene (PNB, PNR)

Properties and Applications

Polynorbornene or polynorbornylene (PNB) is an amorphous, transparent thermoplastic with high glass transition temperature (> 310K). The monomer norbornene is produced via Diels-Alder reaction of ethylene and cyclopentadien and the polymer via ring-opening metathesis polymerization (ROMP) of norbornene (Norsorex process). The resulting polymer contains double bonds in the backbone and can be crosslinked yielding elastomers.¹

PNB is known for its high thermal stability, excellent optical transparency, high index of diffraction, high friction coefficient, and low dielectric constant.
Polynorbornene has a high affinity to aromatic and paraffinic oils which act as plasticizers.  Elastomers made from polynorbornene (NBR) have good heat, ozone, and weathering resistance. They also have excellent noise and vibration damping properties but poor resistance to swelling in most hydrocarbon oils and low abrasion resistance.

PNB is known as a super absorbent polymer for oil. It can absorb up to 30 times of its own weight of oil. Elastomers made from PNB find applications in the automobile, electronic, construction and sports-recreation equipment industry. Major products include shoe parts such as mid-sole constructions for sport and work shoes and slip resistant out-soles; dampers for washing and drying machines; and automotive parts such as bumpers, door sealing and transmission belts.

Manufacturers & Distributors

¹Free radical or cationic polymerization is also possible which yields thermoplastic polymers instead of diene polymers