5-Ethylidene-2-norbornene, copolymerization

Data on a number of copolymers prepared with various catalysts are given in Table 19A [287]. An assumption in this work was that the small proportion of termonomer (ethylidene norbornene) did not interfere with E/ copolymerization. 

The addition copolymerization of norbornene-type monomers with a-olefins [21] forms the basis of EPDM (ethylene propylene diene monomer) technology. Incorporation of smaU amounts of DCPD or ethylidene norbornene (ENB) in olefinic vinyl addition polymers provides latent crosslink sites in EPDM elastomers. It is weU known in the hterature that incorporation of higher amounts of rigid, bulky multicychc olefins results in materials with higher TgS [22]. In fact, more recent work has concentrated on increasing the Tg of norbornene-type monomer/a-olefin copolymers [23]. The use of late transition metal catalysts to prepare such copolymers is reviewed in Section 4.3. 

Important copolymerizations with Ziegler-Natta catalysts are between hydrocarbon monomers. An example is the reaction of ethylene, propylene, and a non-conjugated diene, such as 5-ethylidene-2-norbornene, to produce the so-called EPDM (ethylene-propylene-diene monomer) elastomers. These products have... 

Also, 5-(triethoxysilyl)norbornene took part in addition copolymerization with 5-ethylidene-2-norbornene [223], 5-n-butylnorbornene [228], and unsaturated norbornene [229] in the presence of Pd [223,228] and Ni-catalysts [229]. Copolymer s thin films were crosslinked or hardened for use as polymer-based dielectric material in the interconnection of semiconductor devices [230]. 

For many years Ziegler-Natta coordination copolymerization of ethylene with propylene and non-conjugated dienes (such as hexa-1,4-diene and 5-ethylidene-2-norbornene) has been used to prepare an important class of rubbers known collectively as EPDM rubbers. More recently, copolymerization of ethylene with small proportions of higher a-olefins (such as but-l-ene, hex-l-ene and oct-l-ene) has become important and is used to prepare a range of copolymers known as linear low-density polyethylenes (LLDPE). 

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