Rheological behavior of brominated isobutylene‐co‐paramethylstyrene: Effect of fillers, oil and blending with EPDM

Abstract

The melt flow properties of unfilled and filled brominated isobutylene‐co‐paramethylstyrene (BIMS) were measured by means of a capillary viscometer at three different temperatures (90°C, 110°C and 130°C) and four different shear rates (61, 122, 245 and 306 s−1). The effect of addition of EPDM rubber on melt flow properties of unfilled BIMS was also studied. Evaluation of the processability was done by measuring the extrudate roughness (ER) of the extrudates obtained from the MPT. The viscosity of the systems decreased with the shear rate, indicating their pseudoplastic or shear thinning nature. As expected, the viscosity of BIMS increased with the addition of fillers and decreased with the addition of oil. For the neat systems, viscosity increased with the addition of EPDM, and the blends showed a positive deviation, indicating interdiffusion of the polymer chains across the phase boundaries. The activation energy of the filled systems at constant filler loading increased with increasing filler surface area (N330 > N550 > N774, each at 30 phr loading), and filler loading (50 > 30 > 10 phr, for N330) and decreased with the addition of oil (2.5 > 5.0 > 7.5 phr, for system containing 30 phr of N330). The silica filled system showed a higher activation energy and ER than the carbon black‐filled systems. With addition of N330 and N550 carbon blacks to BIMS, the extrudate roughness (ER) decreased, whereas it increased with the addition of N774 carbon black. With an increase in filler loading, ER initially increased and then decreased as compared to the neat system. For the filled systems, ER initially decreased up to 5 phr of oil, beyond which it increased.

Effects of quasi‐nanogel particles on the rheological and mechanical properties of natural rubber: A new insight

“…that they offer to flow, 8,23,24 with a few exceptions. 7,13,20 In this case, probably the large polymer chains roll over or slip past the comparatively semirigid, quasi-nanogel particles, and this leads to a substantial decrease in the melt viscosity at an intermediate shear rate.…”

Thermorheological studies of novel thermoplastic elastomeric blends of nitrile rubber (NBR) and scrap computer plastics (SCP) based on acrylonitrile–butadiene–styrene terpolymer (ABS)

“…Theoretical values of viscosity at the frequency of 10 rad/s were evaluated for the blends. The deviation in viscosity of blends (∆η) at a given temperature and frequency can be expressed as: 18 …”

Rheological behavior of chlorosulfonated polyethylene composites: Effect of filler and plasticizer

“…This decreases the tendency toward molecular orientation, thus decreasing the pseudoplastic behavior 20. For other filled systems, it is also observed that n increases and k decreases with increase in temperature, indicating a decrease in pseudoplastic behavior and the resistance to flow 2, 13…”

“…Figure 4 shows that at any particular rate of shear and temperature, the DOP‐filled CSM composites has lower viscosity than filled CSM composites with no plasticizer content. This can be explained in the terms of the hydrodynamic effect of the oil, which increases the volume fraction of the flow medium and tends to lower the viscosity of the system 2. Figure 4 shows that an increase in dosage of DOP from 10 to 15 phr in 30 phr carbon black‐loaded CSM composites results in progressively greater decrease in viscosity at the different shear rates and temperatures as compared with the unmodified CSM.…”

“…True shear stresses at corresponding true shear rates were considerably higher for the carbon black‐filled SBR compound than that of the virgin elastomers; however, the addition of black reduces the extent of deviation from Newtonian behavior. Effect of fillers like carbon black and silica on the melt flow properties of unfilled and filled brominated isobutylene‐co‐paramethylstyrene has been reported by Kumar et al2 wherein the silica filled system showed higher activation energy than the carbon black‐filled systems. Rheological properties of self‐vulcanizable rubber blends based on chlorosulfonated polyethylene (CSM) and carboxylated nitrile rubber filled with carbon black were studied by Mukhopadhyay and Gupta 3.…”