Electrical and mechanical properties of grafted and ungrafted polyacrylamide-rubber blends

Abstract

ABSTRACT:A systematic dielectric and mechanical study was carried out on an ethylene propylene diene monomer (EPDM) and a nitrile rubber (NBR) blended with polyacrylamide (PAM). From the compatibility investigations, it was found that EPDM/ PAM is incompatible while NBR/PAM is semicompatible. To overcome the problem of phase separation between rubber and PAM, PAM was grafted with two different monomers, acrylonitrile (AN) and acrylic acid (AA), and added with 10 phr to both EPDM and NBR. Poly(vinyl chloride) (PVC) was also added as a compatiblizing agent to both types of blend. It was concluded that the addition of either a grafted polymer or PVC to the rubber-plastic blend could improve to some extent the compatibility of such blends.

Influences of the grafting percentage of natural rubber‐graft‐poly(2‐hydroxyethyl acrylate) on properties of its vulcanizates

“…The dielectric constant of NR‐ g ‐PHEA vulcanizates increased with amount of grafting due to the higher polarity of PHEA. These results are in agreement with prior studies …”

“…These results are in agreement with prior studies. 23,24 Figure 8(b) exhibits the dissipation factor or dielectric loss tangent (tan ) as a function of frequency for the various NR-g-PHEA vulcanizates. In the lower frequency region, the dissipation factor increased with frequency from 5 MHz to 25 MHz, possibly due to mobile charges.…”

Preparation and characterization of blends containing natural and some synthetic rubbers with synthesized aromatic polyester

“…Raising the AP content in SBR to 20 and 30 phr accompanied by an increase in the strain more than 100% at the stress 1.3 and 1.4 MPa, respectively, Figure 7(b). The decrease in stress–strain of SBR/AP compared to NR/AP may be attributed to the reduction in the adhesion between the two phases in SBR/AP blends and/or the decrease in the dispersion of the components in each other 31. The stress–strain curves of NBR/AP and EPDM/AP blends exhibit nearly similar trends and are represented in Figure 7(c,d), respectively.…”

Compatibility study of natural rubber and ethylene-propylene-diene rubber blends

“…To overcome the problem of phase separation in NR/EPDM blends, we made trials with different compatibilizers. That is, the compatibility of NR/EPDM blends could be improved either by the addition of a third component (compatibilizer) such as BR, chlorosulfonated PE, PVC,15, 16 or EPDM‐ g ‐MAH or by the creation of some crosslinks between the components of the blend by γ‐irradiation.…”

“…Several attempts have been made to minimize phase separation and increase interfacial adhesion. These include the addition of a compatibilizing agent such as a third polymer, that is, a graft or block copolymer that improves the interactions between constituent polymers 12–17. Interfacial agents, including both reactive and nonreactive types, for polymer blends and composites have been the subjects of some reviews 17–19.…”