ETHYLIDENE NORBORNENE COPOLYMER

Fig. 7 IR spectra of ethylene-propylene-ethylidene norbornene copolymer (EPDM) (A) before and (B) after photocrossunking.

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. 

Poly (ethylene-co-propylene). See EPM rubber Poly (ethylene-co-propylene-co-5-methylene-2-norbornene). See Ethylene-propylene-ethylidene norbornene Poly (ethylene-co-tetrafluoroethylene). See Ethylene/tetrafluoroethylene copolymer Poly (ethylene-co-vinyl acetate). See Ethylene/VA copolymer Polyethylene, crosslinked Synonyms XLPE XPE... 

Ethylene/propylene/dicyclopentadiene terpolymer Ethylene-propylene-ethylidene norbornene elastomer, adhesives Epichlorohydrin elastomer Epichlorohydrin/ethylene oxide/allyl glycidyl ether terpolymer Epichlorohydrin/ethylene oxide copolymer Polyisoprene Polyurethane, thermoplastic... 

Amorphous copolymers of ethylene and propylene, EPM, also possess rubber-elastic properties. But they cannot be vulcanized with sulfur because of the absence of carbon-carbon double bonds, and so a special technique using peroxides as free radical sources for transfer reactions has had to be developed. However, polymerizing in a diene component such as, for example, cyclopentadiene or ethylidene norbornene, leads to the formation of what are known as EPDM rubbers with double bonds in the side chains. These can, on the one hand, be vulcanized in the classic way with sulfur, but, on the other hand, still have good aging properties. Consequently, EPDM rubbers are mainly used in automobile construction, the cable and construction industries, as well as for technical purposes. However, the EPDM rubbers have only slight self-adhesion, so that producing tires from cut sections is made more difficult. It is for this reason that EPDM rubbers are not used for tires. 

Problem 11.18 Dienes commonly used in EPDM rubbers include dicyclopentadiene, 4-ethylidene norborn-2-ene, and hexa-1,4-diene. Devise a strategy to prepare (via ATRP and grafting from approach) graft copolymers containing EPDM backbone chains and PMMA branches, the diene used in the EPDM being ethylidene norbornene. 

Polymerisation of ethylene and propylene results in a saturated copolymer. To vulcanise this rubber, some unsaturation must be introduced. This is commonly done by adding a few percent of non-conjugated diene (termonomer) such as dicyclopentadiene, 1,4-hexadiene, or ethylidene norbornene, during polymerisation. Because only one of the double bonds of the diene reacts during polymerisation, the other is free for... 

Yamada and co-workers [42] studied the pyrolysis of vulcanised ethylene, ethylidene norbornene-propylene copolymers at 650 °C. 

Elastomeric ionomers have also been developed from ethylene-propylene-diene ternary copolymers known as EPDM rubbers. The diene is commonly ethylidene norbornene. Du Pont made carhoxylated ionomers by free-radical grafting of maleic anhydride (0.5-5%) onto the diene moiety of the polymer and neutralized the product with rosin salt. The ethylidene norbornene can also be sulfonated, thus ... 

Figure 11.13 Microdomain spacings (d) for hydrogenated poly(norbornene-Z -(ethylidene norbornene)) diblock copolymers, plotted in a format consistent with the scaling law docNfNa. Dashed horizontal lines represent hydrogenated polynorbornene block with indicated number of folds per block. Reprinted with permission from Reference [104]. Copyright 2004 American Chemical Society.

Commercial grades of ethylene-propylene copolymers (EPR) contain 60-75 mol% of ethylene to minimize crystallization. The addition of a third monomer, such as 1,4-hexadiene, dicyclopentadiene, or 5-ethylidene-2-norbornene, produces generally amorphous faster-curing elastomers. A large number of such terpolymers, referred to as EPDM, is available commercially. Their properties, performance, and response to radiation vary considerably depending on macrostructure, ethylene/propylene ratio, as well as on the type, amount, and distribution of the third monomer. 

Copolymers of ethylene (E) or propylene (P) with acrylic acid (AA) or methacrylic acid (MA) were obtained from SP2 (USA) and used as received (EAA, PAA, PEAA, PMA). Copolymers of ethylene and vinyl alcohol (EVOH) were prepared by hydrolysis (NaOH 0,5M in methanol, reflux, 48 h), of commercial ethylene-vinyl acetate copolymers (EVA, Elf-Atochem) containing 5, 9, 14, and 18 w% of acetate. Hydroperoxides of EPDM based on 5-ethylidene-2-norbornene (0.7 mol Kg 1, Exxon) and polyoctenamer (Vestenamer, VEST, Hiils) resulted from a reaction of polymer films with singlet oxygen. 

Random ethylene/propylene copolymers are amorphous and represent an interesting class of synthetic elastomers. The introduction of double bonds, useful for sulphur vulcanisation in the copolymer, can be achieved by copolymerisation of ethylene and propylene with non-conjugated dienes containing only one double bond capable of insertion for instance, 1,4-hexadiene, dicy-clopentadiene and 5-ethylidene-2-norbornene (endocyclic double bond)... 

Ethylene dioxythiophene monomer, emulsion polymerization PEG-5 methacrylate Sodium allyloxy hydroxypropyl sulfonate monomer, EPDM elastomers Ethylidene-2-norbornene monomer, epoxy coatings Bis [f[4-(ethenyloxy) methyl] cyclohexyl] methyl] terephthalate Bis (4-vinyl oxy butyl) hexanediyibiscarbamate monomer, EVA copolymers Vinyl acetate... 

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]. 

Other applications of AFM to the characterisation of polymers include polythiophene [9], nitrile rubbers [10], perfluoro copolymers of cyclic polyisocyanurates of hexamethylene diisocyanate and isophorone diisocyanate [11], perfluorosulfonate [12], vinyl polymers [13], polyhydroxybutyrate [14], polyacrylic acid nanogels [15], acrylic copolymers [16, 17], polyurethanes [18, 19], ethylene methacrylate copolymer [4, 20], polyamides [21], polyvinyl pyrrolidone [22], and polyethyl methacrylate dispersions [23], acryloyl chloride [13], aniline-4-sulfonic acid [24], ethylene propylene 5-ethylidene-2-norbornene terpolymer [25] and butylene adipate - butylene terephthalae [26]. 

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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