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

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)₂ZrCl₂) combined with borate/TIBA. To demonstrate the polymerizations' living character, cyclic VCH with linear-exocyclic and endocyclic 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 (ΔH_m), and their melting temperature (Tm) varies from 109 to 126 °C, and ΔH_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 RE, RVCH, and propagation rate constants kE and kVCH, the quantitative relationship between RE, RVCH and kE, kVCH and catalyst structures, their constituent polymer Mw, and their reactivity response to the endocyclic and exocyclic bonds of VCH. The kinetic parameters RE, RVCH, kE, and kVCH, which are the apparent rates for the metallocene-catalyzed E/VCH, RE, and kpE values, are much more significant than RVCH and kpVCH at 120 s, RE and RVCH 39.63 and 0.78, and the kE and kpVCH values are 6461 and 93 L/mol·s, respectively, and minor diffusion barriers are recommended in the early stages. Compared with previously reported PE, RE and kE values are 34.2 and 7080 L/mol·s. VCH increases the RE 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, k, 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.