Linear non‐conjugated dienes from biomass as termonomers in EPDM synthesis, 2. Comparison with 5‐ethylidene‐2‐norbornene termonomer

Abstract

A comparative study of 5-ethylidene-2-norbornene (ENB) or 5,7-dimethylocta-l,6diene (5,7-DMO) as diene termonomer in ethylene-propylene-diene (EPDM) terpolymer synthesis is presented. The reactivities of the cyclic and linear non-conjugated dienes are first compared in homopolymerization in the presence of two conventional Ziegler-Natta catalytic systems: TiCl,, 1/3A1C13, 14MgC1, associated to AIEt,, and VOCl, (or VCI,) associated to AlEt,Cl. ENB polymerization yields a branched poly(ENB) in agreement with a predominant cationic reaction, whereas polymerization of 5,7-DMO proceeds exclusively by a Ziegler-Natta mechanism. In terpolymerization, ENB is much more reactive than 5,7-DMO and is incorporated more easily in the terpolymer. However, the high sensitivity of ENB toward acidic species also results in cationic side reactions and therefore limits the utilization of ENB to a low concentration range. We have shown that the productivity of vanadium catalysts, which are mainly used in industrial EPDM synthesis, is drastically reduced in the presence of ENB an 5,7-DMO, due to the rapid reduction of vanadium involving the diene.

Functionalisation of Polyolefins: Grafting of Phenol Groups on Olefin/5,7‐Dimethylocta‐1,6‐diene Copolymers

“…In previous works we have investigated the copolymerization of 5,7-DMO with ethylene [15,16] and its terpolymerisation with ethylene and propylene, [17][18][19] in the presence of various metallocene catalytic systems. High Full Paper: The grafting of phenol groups on ethylene/5,7-dimethylocta-1,6-diene copolymers and on ethylene/propylene/5,7-dimethylocta-1,6-diene terpolymers was performed, using two different modification procedures.…”

Residual metal content in Ethylene-Propylene-Diene Monomers synthesized using vanadium- and zirconocene-based catalysts

“…34 Besides, it was already shown that only 18% of the V in the reaction milieu is present as active species. 35 In a previous study, 25 we observed that the Al/V molar ratio incorporated in polymers remains roughly constant (between 6.0 and 7.5) independent of the initial Al/V molar ratio in the solution, which was attributed to the percentage of active V(III) species. Then it seems that the amount of Al/V, which remains in the polymer, corresponds to the metal ratio necessary to generate the active species.…”

Dynamic modeling of crosslinking and gelation in continuous ethylene–propylene–diene polymerization reactors using the pseudo–kinetic constant approach

“…The linkage is initiated by the interaction of a PDB with cocatalyst to form an active (carbenium-ion terminated) branch (Kresge et al, 1985;ver Strate, 1985;Pehlert et al, 2001). However, direct vinylic coupling of PDBs has also been observed, for example in vinyl norbornene homopolymers using AlEtCl 2 as catalyst (Kennedy and Makowski, 1967;Dolatkhani et al, 1996). Regardless of the number of intervening links in a branch, the crosslink is not complete until the branch reacts with another PDB.…”

“…The curve relating the two could be reproduced exactly only by assuming that the amount of consumed PDBs was proportional to the square of the diene content. Also, Dolatkhani et al (1996) studied the kinetics of homopolymer diene systems, some of which crosslinked. The crosslinking systems were ENB=VOCl 3 =AlEt 2 Cl and ENB=TiCl 3 =AlCl 3 .…”