Both amorphous and semicrystalline polymers used in this document have a Mooney viscosity of 70, and an ethylidene norbornene
(ENB) content of 5%.
Non-conjugated diene monomers such as ethylidene norbornene
(ENB), hexadiene (HX) and dicyclopentadiene (DCPD) are added to ethylene propylene polymers to provide unsaturation sites for curing purposes.
Each grade is synthesized with a different diene termonomer; vinyl norbornene, 1,4-hexadiene and ethylidene norbornene
, and are referred to here as EPDM-VNB, EPDM-HEX and EPDM-ENB, respectively.
Injection-grade isotactic polypropylene from Himont Co., and EPDM based on ethylidene norbornene
(ENB) as a diene monomer (Keltan), supplied by DSM Elastomers Europe, were used as commercially available.
Unsaturation content of EPDM: Ethylidene norbornene
Jiang and Hamed (13) reacted fullerene ([C.sub.60]) with the hindered double bond of ethylidene norbornene
in EPDM at 105 [degrees] C by cycloaddition.
Commonly used third monomers today are ethylidene norbornene
, dicyclopentadiene and 1,4-hexadiene.
All of these polymers are considered amorphous and contain ethylidene norbornene
(ENB) cure sites.
This is different from our previous study with a rubber made with ethylidene norbornene
curesite comonomer (ref.
In our development efforts we have concentrated on ethylidene norbornene
(ENB) as the diene of choice for EPDM, but 1,4-hexadiene, dicyclopentadiene and other comonomers can be used.
There are three types of termonomers commercially used in EPDM: DCPD (dicyclopentadiene), HD (1,4-hexadiene) and ENB (ethylidene norbornene