Interplay between key variables of peroxide cured EPDM and evaluation of electromechanical efficiency for MV cables

Abstract

Extensive work has been done on ethylene-propylene-diene monomer (EPDM) vulcanizates and the main factors influencing their cure efficiency. However, very little attention has been given to the evolution of material properties and the interplay between key variables formulation. The effect of ethylene/propylene content and concentration of peroxide and type on viscoelastic and dielectric properties of EPDM elastomers was investigated using dynamic mechanical analysis and electric property measurements at room temperature. In order to compare results, these measurements were obtained by FTIR spectroscopy. Differences between real and imaginary (loss) part of the permittivity of EPDM/ dicumyl peroxide (DCP) composites were more significant than those in EPDM/di(tert-butylperoxyisopropyl)benzene (DTBPIB) composites. For peroxide DTBPIB, the dielectric percolation limit moves further with the increase of ethylene content of EPDM. The dielectric percolation limit of the peroxide DTBPIB is found to be approximately 60 g at a 75% of ethylene in EPDM. The FTIR analysis showed that a termoxidative degradation was promoted at mixes with peroxide DCP at 45 and 75% of ethylene in EPDM. Therefore, we could interestingly show the decrease in electrical properties particularly associated with termoxidative degradation of peroxide DCP.

Simultaneous crosslinking and foaming of ethylene‐propylene diene terpolymers (EPDM) organoclay composite foams

“…The characteristic peaks related to EPDM functional group were observed around 2915 cm À1 and 2839 cm À1 (stretching vibration of CH 2 ), 1459 cm À1 and 1370 cm À1 (in-plane bending vibration of C H bond), and 715 cm À1 (out-plane bending vibration of C H bond). 49 There was no change noted in the spectra after the incorporation of DCP and sheet formation at low temperature (at 130 C), which confirms the absence of reaction or crosslinking at low temperature. On the contrary, changes in the spectra (1340-760 cm À1 ) were observed after curing the sample at 200 C, which was prominently visible after extraction and analyzing the gel confirming the crosslinking of EPDM macromolecules as proposed in Figure 3B.…”

“…Furthermore, the reaction of DCP and EPDM was also analyzed using FTIR and shown in Figure 3C. The characteristic peaks related to EPDM functional group were observed around 2915 cm −1 and 2839 cm −1 (stretching vibration of CH 2 ), 1459 cm −1 and 1370 cm −1 (in‐plane bending vibration of CH bond), and 715 cm −1 (out‐plane bending vibration of CH bond) 49 . There was no change noted in the spectra after the incorporation of DCP and sheet formation at low temperature (at 130°C), which confirms the absence of reaction or crosslinking at low temperature.…”

Relationships of the Degree of C=C Double Bond Conversion with the Dielectric Properties for SiO2/1,2‐PB/SBS/EPDM Composites Cured by Organic Peroxide

“…The peroxides can be used as initiators for cross‐linking and curing due to hydrocarbon resins containing C=C unsaturated double bonds. The amount of peroxide will affect the number of free radicals in the system, which affects the cross‐linking reaction rate, the cross‐linking quality of the system, and affect the performance of the material [17,18] …”

“…The amount of peroxide will affect the number of free radicals in the system, which affects the cross-linking reaction rate, the cross-linking quality of the system, and affect the performance of the material. [17,18] The measurement of crosslinking density is one of the most efficient methods for revealing structural information on a crosslinked polymer network. The gel content and swelling ratio are usually used to characterize the crosslink density of composite materials.…”