Numerous metallocene catalysts with different substituents have been investigated to manufacture these polymers. To overcome these problems, academic and industrial researchers used single-site homogeneous metallocene catalysts for the synthesis of E and P homopolymers, E.P., and EPDM since the 1990s. In addition, with a large amount of vanadium (V) in the polymeric product, very expensive equipment have to be used to remove the residual V.
The disadvantages of these catalysts were low stability and catalytic activity. and EPDM was largely based on vanadium-based catalysts such as VOCl 3 and VCl 4. From the discovery of the Ziegler–Natta catalyst to 1990, the manufacturing of E.P.
The Ziegler–Natta catalyst system was developed in the 1960s and has been broadly used up to now in polyolefin industries. (2−5) These elastomers were produced with heterogeneous Ziegler–Natta (Z-N) catalysts through ion coordination-based polymer reactions. Although the slope of low frequencies in polymers holding potent exoelectrogenic bacteria ( Shewanella oneidensis MR-1) as a charge carrier in the electrolyte could significantly reduce the Warburg resistance, it still could not improve the conductivity, which demonstrated that the external charge supply could not alter the insulating property in the used polymers.Įthylene propylene with dienes and EPDM elastomers are manufactured on a large scale, with annual production exceeding 100 million tons. The EIS Nyquist plot showed high Warburg impedance features in the low-frequency domain with straight lines without a semicircle, suggesting that the property of the polymer owing to the high electrical resistance and poor conductivity for ionic kinetics in the electrolyte may have surpassed that of the semicircle. EIS is an effective method to investigate the polymers’ interfacial electron transfer characteristics. To examine the insulating property, the interface characteristics of the polymer were evaluated using electrochemical impedance spectroscopy (EIS) with a frequency range of 1 × 10 5–0.01 Hz and an amplitude of 5.0 mV. Also, this work reveals that these polymers can be a better candidate for high-voltage electrical insulation due to their enhanced dielectric, mechanical, and thermal characteristics. In addition, low dielectric loss suggests the suitable application potential of these polymeric materials for the fabrications of capacitors. Second, this paper presents a kind of elastomeric polymers based on E/1-hexene and VCH with a high dielectric constant ( k = 6–4) and mechanical properties. In previous reports, ethylene propylene monomer dienes (EPDM) had a low content and were used for dielectric and insulating properties with nanomaterials.
Terpolymerizations of newly synthesized ethylene (E), vinylcyclohexene (VCH), and 1-hexene were carried out with symmetrical metallocene catalysts rac-Me 2Si(2-Me-4-Ph-Ind) 2ZrCl 2 (catalyst A) and rac-Et(Ind) 2ZrCl 2 (catalyst B).
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