EPDM

In this research the variation of mechanical and rheological properties of the composite as a function of different processing parameters and ethylene propylene diene monomer (EPDM) rubber content was studied. The optimum amount of dicumyl peroxide (DCP) to achieve the highest percentage of grafting of maleic anhydride to EPDM was obtained by Fourier transform infrared (FTIR) spectroscopy. In general, immiscibility between nylon 66 and EPDM, and their high interfacial tension makes their blending difficult. Maleic anhydride was grafted to EPDM to reduce interfacial tension between two phases. Also the blends were prepared at highest possible speed of mixing (screw speed in extrusion) and lowest temperature to reach a well mixed sample which can be seen in scanning electron microscopy (SEM) images and impact strength results. Dynamic mechanical thermal analysis (DMTA) tests were conducted to evaluate the miscibility of the components and to measure the glass transition temperature of...

The curing characteristics and mechanical properties of natural rubber/polypropylene blends were investigated with the aim of improving tensile strength. Two different types of filler were tested: carbon black and reclaimed rubber. It was found that, the increasing carbon black compositions improve the tensile strength of the NR/PP blends. Reclaimed rubber shows beneficial effect by increasing the scorch time and decreasing the cure time of the NR/ PP blends. And the use of reclaimed rubber results in compositions of improved elasticity and tensile mechanical performance.

In this research the variation of mechanical and rheological properties of
the composite as a function of different processing parameters and ethylene
propylene diene monomer (EPDM) rubber content was studied. The optimum
amount of dicumyl peroxide (DCP) to achieve the highest percentage of grafting of
maleic anhydride to EPDM was obtained by Fourier transform infrared (FTIR)
spectroscopy. In general, immiscibility between nylon 66 and EPDM, and their high
interfacial tension makes their blending difficult. Maleic anhydride was grafted to
EPDM to reduce interfacial tension between two phases. Also the blends were
prepared at highest possible speed of mixing (screw speed in extrusion) and lowest
temperature to reach a well mixed sample which can be seen in scanning electron
microscopy (SEM) images and impact strength results. Dynamic mechanical
thermal analysis (DMTA) tests were conducted to evaluate the miscibility of the
components and to measure the glass transition temperature of the blends.
Rheological measurement showed that the viscosities of the components of the
blend getting closer to each other when EPDM content, time of mixing and shear
rate increase.

A novel mixing approach for achieving a good dispersion of multi-walled carbon nanotubes (MWCNTs) in ethylene- propylene diene monomer (EPDM) matrix has been investigated. In this approach EPDM was modified with vinyltrimethoxysilane (VTMS) during melt mixing. In addition the effect of MWCNT concentration on mechanical and rheological properties of modified EPDM has been studied. The formulated composites by this method exhibited significantly enhanced physical properties even at very low nanotube concentration. The grafting reaction was confirmed by Fourier transform infrared spectroscopy (FT-IR) peak at 1070 and 1250 cm-1according to Si-O and Si-C vibration. The state of dispersion of the fillers in the polymer matrix was evaluated through transmission electron microscopy (TEM) and scanning electron microscopy (SEM), In addition surface topology was studied with atomic force microscopy (AFM). The results showed that VTMS-grafted on the EPDM surface improved the dispersion of MWCNTs in the matrix. The rheological characteristics have been studied by rubber process analyzer (RPA). Some properties such as storage modulus (Ǵ) and complex viscosity (η^*) increased with increasing MWCNT content. It was found that at concentration of 2 wt.% MWCNT, the nanocomposites exhibited notably enhanced mechanical properties such as modulus and tensile strength.

Pure and oil extended ethylene propylene diene monomer nanocomposites were prepared using suitable compatibilizer. Since ethylene propylene diene monomer (EPDM) is non-polar, incorporation of organically modified nanoclay may not lead to better dispersion in the rubber matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer for dispersing nanoclay in the EPDM matrix. ENR-organically modified nanoclay composites (EC) were prepared by solution mixing. The nanoclay used in this study is Cloisite 20A. ENR-nanoclay composites were incorporated in EPDM and oil-extended EPDM (OE-EPDM) matrices along with carbon black. The morphological studies prove that the nanoclay platelets get intercalated in ENR. Low loading of EC in EPDM and OE-EPDM matrices enhances the dispersion of nanoclay forming partially exfoliated platelets. Curing study shows improvement in torque and faster cure time for the compatibilized EPDM and OE-EPDM nanocomposites containing dual filler system compared to pure and single filler (carbon black) containing rubber compounds. Dynamic mechanical thermal analysis shows high storage modulus and lesser damping characteristics for the dual fillers containing EPDM and OE-EPDM compounds. The same compounds show tremendous improvement in mechanical properties. Scanning electron microscopic (SEM) images of tensile fractured single and dual filler containing rubber specimens show rough and tortuous path of fracture, which may be due to physical interaction between filler and rubber.

Evolution of the surface characteristics of EPDM elastomer was studied as a function of thermal ageing at 80 degrees C and 120 degrees C in air for up to 100 days. The components of the surface free energy (SFE) were determined from contact angle measurements of five liquids using acid-base regression and Fowke's theories. SFE increased with ageing duration. For