Methods for Predicting Ethylene/Cyclic Olefin Copolymerization Rates Promoted by Single-Site Metallocene: Kinetics Is the Key.

In toluene at 50 °C, the vinyl addition polymerization of 4-vinyl-cyclohexene (VCH) comonomers with ethylene is investigated using symmetrical metallocene ( rac -Et(Ind) 2 ZrCl 2 ) combined with borate/TIBA. To demonstrate the polymerizations' living character, cyclic VCH with linear-exocyclic π and endocyclic π bonds produces monomodal polymers, but the dispersity (Ɖ) was broader. The copolymers obtained can be dissolved in conventional organic solvent and have excellent thermal stability and crystalline temperature (Δ H m ), and their melting temperature (Tm) varies from 109 to 126 °C, and Δ H m ranges from 80 to 128 (J/g). Secondly, the distribution of polymeric catalysts engaged in polymer chain synthesis and the nature of the dormant state are two of the most essential yet fundamentally unknown aspects. Comprehensive and exhaustive kinetics of E/VCH have shown numerous different kinetic aspects that are interpreted as manifestations of polymeric catalysts or of the instability of several types of active center [Zr]/[C*] fluctuations and formation rates of chain propagation R p E, R p VCH, and propagation rate constants k p E and k p VCH, the quantitative relationship between R p E, R p VCH and k p E, k p VCH and catalyst structures, their constituent polymer Mw, and their reactivity response to the endocyclic and exocyclic bonds of VCH. The kinetic parameters R p E, R p VCH, k p E, and k p VCH, which are the apparent rates for the metallocene-catalyzed E/VCH, R p E, and kp E values, are much more significant than R p VCH and kp VCH at 120 s, R p E and R p VCH 39.63 and 0.78, and the k p E and kp VCH values are 6461 and 93 L/mol·s, respectively, and minor diffusion barriers are recommended in the early stages. Compared with previously reported PE, R p E and k p E values are 34.2 and 7080 L/mol·s. VCH increases the R p E in the initial stage, as we are expecting; this means that the exocyclic bond of VCH is more active at the initial level, and that the chain transfer reaction of cyclic internal π double is increased with the reaction time. The t p versus R p , k p , and [Zr]/[C*] fraction count may be fitted to a model that invokes deactivation of growing polymer chains. At t p 120-360 s higher, the incorporation rate of VCH suppresses E insertion, resulting in reduced molecular weight.