Assessment of compatibilization role of nanoclay in immiscible polystyrene/ethylene–octene copolymer blends via wide‐angle X‐ray scattering, microstructure, rheological analyses, and mechanical properties

Abstract

Polystyrene (PS)/ethylene–octene copolymer (EOC) blends with 80/20 wt % composition containing different amounts (0, 1.0, 2.5, 5.0 and 7.5 wt %) of an organically modified nanoclay were prepared by one‐step melt‐mixing method. Also, the EOC‐rich blends with 80 wt % EOC content loaded with 0 and 5.0 wt % of the nanoclay were prepared under the similar processing conditions. Presence of both PS and EOC chains in between clay layers localized at the interface of the blends could be deduced by X‐ray diffraction analysis, which suggested formation possibility of PS‐EOC physical structures at the blend interface. Transmission electron microscopy results confirmed that clay nanoparticles were mainly localized at the interface of the blends and also partly in the PS and EOC components of the systems. The localization of the nanoclay was also described by the linear viscoelastic melt rheological studies. It is also revealed that nanoclay had stronger interactions with PS than EOC. This is reflected in the higher tensile properties in the PS‐rich system. The analysis of morphology of the developed systems by emulsification curve revealed that the optimum amount of nanoclay to modify PS‐rich blend is 2.5 wt %. At this clay loading, the blend exhibited the highest impact resistance. According to the overall results, suitability of nanoclay was confirmed for compatibilization of the PS/EOC blends. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48748.

Flexible high dielectric polystyrene/ethylene‐α‐octene copolymer/graphene nanocomposites: Tuning the morphology and dielectric properties by graphene's surface polarity

“…Therefore, the morphological change in this sample is not related to the interfacial energy and can be explained by the viscosity ratio; the PS phase's solubility parameter is 9.1 cal/cm 3 , and this amount for EOC phase is 8.4, so the PS phase is more polar. 23 Therefore, the non-polar GN nanoplatelets select EOC phase to be localized. 23 Also, this preferential location is because of the lower viscosity of EOC phase.…”

“…23 Therefore, the non-polar GN nanoplatelets select EOC phase to be localized. 23 Also, this preferential location is because of the lower viscosity of EOC phase. 35 Moreover, with GN nanoplatelets' presence, the viscosity of the EOC phase increases, and the viscosity ratio reaches one.…”

“…Figure 8 shows the rheological behavior of pure PS, EOC, and PS/EOC 80/20 wt%. According to Figure 8A, all of the samples have Newtonian behavior in low frequencies, which among them, the PS/EOC 80/20 wt% blend has the lowest range of Newtonian behavior and in average frequencies shows shear-thinning behavior considering the Cox-Merz rule 23. Figure8B,C shows storage modulus and loss modulus in the aspect of frequency, respectively.…”

“…6 Ethylene octene copolymer (EOC) is a new member of polyolefin elastomers and has been used to enhance thermoplastics' ductility because of its good processability and high impact resistance in recent years. 23 Because of PS and EOC's thermodynamic immiscibility, adding of block copolymers and in situ compatibilization has been used for compatibilization of PS and EOC phase. [17][18][19][20][21][22] Recently, Kiani et al 23 have investigated the effect of nanoclay sheets on the compatibilization of PS/EOC/nanoclay blend nanocomposites.…”

“…23 Because of PS and EOC's thermodynamic immiscibility, adding of block copolymers and in situ compatibilization has been used for compatibilization of PS and EOC phase. [17][18][19][20][21][22] Recently, Kiani et al 23 have investigated the effect of nanoclay sheets on the compatibilization of PS/EOC/nanoclay blend nanocomposites. According to this investigation, nanoclays prefer to stay in the interface of phases and increase rheological storage modulus.…”