Ethylene/norbornene copolymers

Figure 14 Crystallinity of ethylene/norbornene copolymers. (From Ref. 25. Reprinted with permission from Elsevier Science.)...

The alternating copolymers are characterized both by a glass transition temperature (130°C for ethylene/norbornene copolymers) and a melting point (295°C for the totally alternating copolymer). The melting point and the crystallinity of these copolymers may be influenced by choice of the metallocene and the conditions of polymerization. Compared with the statistical copolymers, the alternating structures show better resistance to nonpolar... 

Fig. 28. Dependence of the glass transition temperature of ethylene/norbornene copolymers produced by various metallocene/MAO catalysts on the incorporation of norbornene (24).

Single-site metallocene catalysts are also highly reactive vis-a-vis cycloolefins such as cyclobutene, cyclopentene or norbornene. While homopolymers of these cycloolefins have melting temperatures (>380°C), much too high for technical processability, ethylene-cycloolefin copolymers (COC s) - e.g. ethylene-norbornene copolymers - are amorphous materials with glass transition temperatures, above which they become soft and processable [W. Kaminsky, J. Polym. Sci. A, Polym. Chem., 2004, 42, 3911]. 

Ethylene-norbornene copolymers, which have thermoplastic properties when heated above their glass transition temperatures of ca. 200-250°C, have been commercialized by Ticona GmbH under the trade name TOPAS (Tliermoplas-tic Olefin Polymer of Amorphous Structure). Their properties - exceptional transparency, low double refraction, high stiffnes and hardness, low permeability for moisture and excellent biocompatibility - make these ethylene-norbornene copolymers particularly valuable as engineering polymers, for optical applications and as materials for food and medical packaging. 

Figure 25 Alternative concatenation microstructures in ethylene-norbornene copolymers.

Finally, the ethylene/norbornene copolymers obtained using the nickel catalysts are essentially indistinguishable from those obtained using metaUocene-based early transition metal catalysts, both in terms of the microstructure and such physical properties as Tg and tensile modulus. For the ethylene/norbornene polymers synthesized, the glass transition temperature (Tg) increases smoothly with increasing norbornene content. 

Fig. 18 X-ray powder diffraction profiles of ethylene-norbornene copolymer samples with norbornene content close to 50% (A)-(C), and solid norbornane in f.c.c. polymorph stable a T>30.6°C, (D) redrawn from [121]. Sample (A) is a random copolymer and amorphous. Samples (B) and (C) have a prevailing alternating constitution and are both crystalline. Sample (C) is essentially atactic, whereas sample (B) has a prevailing diisotactic configuration. (Reprinted with permission from [121]. Copyright 2003 by the American Chemical Society)...

CYCLIC OLEFIN POLYMERS. See Ethylene-Norbornene Copolymers. 

Cyclic olefin monomers are derivatives of CPD or DCPD. Norbomene derivatives are produced by the Diels-Alder condensation of an olefin and CPD. For instance, 2-norbornene (9) is obtained by reacting excess ethylene with DCPD at a high temperature (>200°C) and pressure (>2900 psia), the condition in which the DCPD is cracked to CPD (64). Reactions of CPD or DCPD at high temperatures with styrene and norbomene yield, respectively, the phenylnorbomene (10) and tetracyclododecene (11) (see Ethylene-Norbornene Copolymers). 

More About Engineering Thermoplastics. Many of the individual resins mentioned in this overview are covered in articles devoted to them. Cross references are provided in Table 1. A list of related articles is as follows Acetal Resins Acrylic Ester Polymers Acrylonitrile and Acrylonitrile Polymers (SAN and ABS) Ethylene-Norbornene Copolymers Liquid Crystalline Polymers, Main-Chain Methacrylic Ester Polymers ... 

ETHYLENE POLYMERS, LLDPE. See Volume 2. ETHYLENE-ACRYLIC ELASTOMERS. See Volume 2. ETHYLENE-NORBORNENE COPOLYMERS. See Volume 2. ETHYLENE-PROPYLENE ELASTOMERS. See Volume 6. EXTRUSION. See Volume 2. 

SCHEME 20.14 Strictly alternating ethylene-norbornene copolymers enriched in r dyads prepared through ROMP and subsequent hydrogenation (TsH = p-toluenesulfonhydrazide). 

Makrocka-Rydzyk Monika, Nowaczyk Grzegosz, Glowinkowski Stanislaw, and Jurga Stefan. Dynamic mechanical study of molecular dynamics in ethylene-norbornene copolymers. Polymer. 51 no. 4 (2010) 908-912. 

Ethylene/norbornene copolymers are presently available commercially from TOPAS Advanced Polymers, Inc., a company formed in 2006 after early development efforts by Hoechst AG and Mitsui Petrochemical. Hoechst initiated the commercialization of this cyclic olefin copolymer (COC) in 1990, and Mitsui Petrochemical became involved in evaluating the manufacture of these copolymers in a continuous pilot-scale operation in 1993. TOPAS Advanced Polymers, Inc., is a joint venture of Daicel Chemical Industries Ltd., and Polyplastics Co., Ltd., with headquarters in Frankfurt, Germany, and a United States subsidiary in Florence, Kentucky. The structure of this copolymer is shown in Figure 4.26. 

Unlike typical ethylene-based copolymers available in the polyethylene industry, which are semicrystalline materials, the ethylene norbornene copolymers are amorphous thermoplastic materials with a high heat distortion temperature of up to 170°C. They have a glossy, crystal clear appearance, with a high modulus (stiff material) and low shrinkage, which are important in the processability of the molten material. The high modulus of this copolymer is not unexpected. The polymer backbone due to the... 

Wang, W. and Nomura, K. (2005) Remarkable effects of aluminum cocatalyst and comonomer in ethylene copolymerizations catalyzed by (arylimido)(aryloxo)vanadium complexes Efficient synthesis of high molecular weight ethylene/norbornene copolymer. Macromolecules, 38,5905-5913. 

PP COC COC = amorphous ethylene/norbornene copolymer Tg = 75 °C blend phase separated and fibrillation was observed 374... 

Fig. 11 Interaction parameter /sans for ethylene-norbornene copolymer blends computed from Eqs. 3 lb and 32c as a function of the composition of component 1 (N Ei x). Different curves correspond to various compositions / of component 2 (N Ei ). The dimensionless exchange energy e is chosen as s/kT = 10 , and z = 6. Note that the computed XSANS is independent of blend composition within the BLCT...

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