In situ fibrillation of polypropylene/polyamide 6 blends: Effect of organoclay addition

Abstract

In situ fibrillation of PP/PA6 blends (85/15 wt %) is investigated in presence of two kinds of organically modified montmorillonite, differing by the polarity of their surfactant. The organoclay is primary dispersed either in the PP (for the low-polarity Cloisite V R 15A) or in the PA6 (for the high-polarity Cloisite V R 30B), according to its assumed affinity. In absence of organoclay, a fibrillar morphology is achieved after the melt-blending and hot-stretching step, as evidenced by SEM analysis. Upon clay addition, different morphological trends are evidenced. The C15A leads to a refinement of the fibrils whether the C30B induces a transition from fibrillar to nodular structure. These trends are ascribed to drastic changes in viscosity and elasticity ratios, due to the filler initial localization. Several techniques (DSC, STEM) point out a C15A migration from the PP to the PP/PA6 interface. Rheological measurements highlight the possibility of a double-percolation phenomenon, linked to the fibrillar microstructure of the PP/PA6/C15A blend.

The outstanding ability of nanosilica to stabilize dispersions of Nylon 6 droplets in a polypropylene matrix

“…and Table ) and the viscosities of the dispersed phase and the matrix Pas and =339.8 Pas, a value of α = 3.8 mN/m is obtained for the interfacial tension of our PP/PA blend. This value is closer to α = 5 mN/m, found by Chomat et al for PP/PA6 blends at T = 240 °C, but is lower than α = 9 mN/m reported by Shi et al for PP/PA6 blends at T = 230 °C, determined using the Palierne method. Comparatively, other literature results show that the interfacial tension of PP/PA6 blends is considerably reduced, down to α = 3 mN/m at T = 230 °C, when maleated polypropylenes were used as compatibilizers.…”

Toughening of poly(lactic acid) without sacrificing stiffness and strength by melt-blending with polyamide 11 and selective localization of halloysite nanotubes

“…In the longitudinal direction (Figure 2a'), an heterogeneous discontinuous fibrillar morphology is observed which is attributed to the viscosity difference between the PLA and PA11 [24]. Whatever the observation direction, the interface between PA11 and PLA seems to be weak, a clear gap between the PLA matrix and the PA11 domains being clearly observed.…”

Effect of selective localization of carbon nanotubes in pa6 dispersed phase of PP/PA6 blends on the morphology evolution with time, part 2: Relaxation of deformed droplets after cessation of flow

“…. Both ratios increase upon CNT addition which could only lead to significant difficulties in dispersion . The selective localization of CNTs in the dispersed phase has caused a dramatic increase in the viscosity and elasticity ratios.…”

“…Therefore, the quality of dispersion has reduced. If CNTs were located in the matrix, they might have performed like compatibilizers and improve the dispersion quality by reducing the aforementioned ratios .…”

“…The incorporation of different compatibilizing agents has been considered in a lot of works for many years . However, it is only recently that the role of nanoparticles in controlling the morphology of immiscible polymer blends has attracted attention . Most of the work on the subject is focused on the effects of nanoparticles on the final morphology and mechanical, rheological, and electrical properties .…”