Preparation and characterization of vinyltrimethoxysilane and dicumyl peroxide-cured (ethylene propylene diene monomer)/polypropylene thermoplastic vulcanizates

Thermoplastic vulcanizates nanocomposites based on polypropylene (PP) and ethylene–propylene-diene terpolymer rubber (EPDM) blends reinforced with organoclay modified montmorillonite have been prepared via melt intercalation. The silicate layers of the clay were intercalated and dispersed at a nanometer level in the matrix blends. The nanocomposites exhibit improved mechanical properties, this effect being more evident at high EPDM contents in the blend (above 80%). This behavior is attributed to the fact that the EPDM chains are more easily inserted into the galleries silicate, giving rise to a more intercalated structure as was observed by X-ray diffraction.

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Characterization of Dielectric Relaxation Process by Impedance Spectroscopy for Polymers: Nitrile Butadiene Rubber and Ethylene Propylene Diene Monomer

Journal of Spectroscopy ◽

10.1155/2020/8815492 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Jae Kap Jung ◽

Young Il Moon ◽

Gyung Hyun Kim ◽

Nae Hyung Tak

Keyword(s):

Dispersion Analysis ◽

Relaxation Processes ◽

Segmental Motion ◽

Butadiene Rubber ◽

Ethylene Propylene Diene Monomer ◽

Molecular Models ◽

Temperature Dependent ◽

Ethylene Propylene ◽

Nitrile Butadiene Rubber

We invented a dispersion analysis program that analyzes the relaxation processes from dielectric permittivity based on a combination of the Havriliak–Negami and conductivity contribution functions. By applying the created program to polymers such as nitrile butadiene rubber (NBR) and ethylene propylene diene monomer (EPDM), several relaxation processes were characterized: an α process due to segmental motions of the C-C bond, an α′ process attributed to fluctuations in the end-to-end dipole vector of the polymer chain, the conduction contribution by the filler observed above room temperature, and secondary relaxation processes β and γ of motion for the side group in NBR. In the EPDM specimen, the β process associated with the rotational motion of the side groups, the α process associated with the relaxation of local segmental motion, and the αβ process associated with the origin of the β process at high temperatures above 305 K were observed. The Maxwell–Wagner–Sillars effect and conduction contribution were also presented. The molecular chains responsible for the relaxation processes were assigned by building molecular models of the two polymers. The temperature dependence of the relaxation strength and the shape parameters that characterize the process were investigated. From the temperature-dependent relaxation analysis, the merged αβ process, activation energy, and glass transition temperature were determined and compared.

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Formulations for thermoplastic vulcanizates based on high density polyethylene, ethylene-propylene-diene monomer, and ground tyre rubber

Journal of Composite Materials ◽

10.1177/0021998310369596 ◽

2011 ◽

Vol 45 (11) ◽

pp. 1189-1200 ◽

Cited By ~ 20

Author(s):

J. Cañavate ◽

P. Casas ◽

X. Colom ◽

F. Nogués

Keyword(s):

Mechanical Properties ◽

High Density Polyethylene ◽

Thermoplastic Elastomers ◽

High Density ◽

Ethylene Propylene Diene Monomer ◽

Good Balance ◽

Ethylene Propylene ◽

Thermoplastic Vulcanizates ◽

Ground Tyre Rubber ◽

Rubber Phase

Thermoplastic vulcanizates (TPVs) are a specific group of the so called thermoplastic elastomers. The main characteristic is the existence of a crosslinked rubber phase obtained by dynamic vulcanization in the presence of the thermoplastic matrix. This article studies TPVs based on ground tyre rubber (GTR), high-density polyethylene, and ethylene propylene diene monomer rubber. Vulcanization is performed by a new peroxide developed to resist high temperatures and an standard one. The aim of this study is optimize the formulation in order to include GTR, while maintaining a good balance of properties in the final TPV material. The use of GTR would improve the possibilities of recovering tyre waste. A detailed study regarding the influence of each component in the final mechanical properties has been carried out. The swelling properties, ATR infrared spectroscopy, TGA, and DSC analysis indicated a high degree of crosslink and good adhesion between the matrix and the rubber phase. Morphology of the composites was assessed by scanning electron microscopy. A composite containing a combination of peroxides and 40/30/30 of HDPE, EPDM, and GTR was found to show a good balance of characteristics regarding mechanical properties, crosslinking, and adhesion between phases.

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