Stabilization of PE/PEO Cocontinuous Blends by Interfacial Nanoclays

Abstract

Organomodified clays are known to be effective in polymer blend compatibilization if located preferentially at the domain interfaces, but little is known regarding the origin of their localization. In this study, we investigate the effect of organomodifier, clay loading, and shear environment on the compatibilization extent in nonreactive polyethylene (LDPE)/ poly(ethylene oxide) (PEO) and reactive maleic anhydride functional polyethylene (PE-g-MA)/PEO polymer blends. We pose important questions: If clay is to compatibilize blends by interfacial localization, how does organomodifier affect its localization? How does an increase in clay loading affect the shape and elasticity of the interface? What is the shear intensity needed to overcome the equilibrium distribution of clays and delaminate it from the interface? We utilize laser scanning confocal microscopy and 3D image analysis to calculate characteristic phase size and gain unique insights into the connection between the clay loading and the interfacial curvature. Our experiments demonstrate that 1 wt % of interfacially localized clay is sufficient to suppress coarsening and greatly reduce phase domains. However, further increase of clay loading only saw a marginal reduction in phase size compared to 1 wt % clay loading. The interfacial curvature calculations showed that with increase in clay loadings beyond 1 wt % the shape of the interface does not change significantly; however, slight broadening of curvature distribution and increasing asymmetry are observed from 3D images. This can be attributed to the multiple layers of clay jammed at the interface at higher clay loadings. When reactive PE-g-MA was substituted for LDPE, graft copolymers were generated via in situ coupling at the interface. These copolymers combined with clay resulted in the smallest phase domains. In addition, we show that clay dispersion and localization were largely independent of shear intensity, which suggests that clay does not delaminate from the interface even in high shear environments.

Phase structure, rheology and electrical conductivity of co-continuous polystyrene/polymethylmethacrylate blends filled with carbon black

“…A C C E P T E D ACCEPTED MANUSCRIPT 14 properties in comparison to directly mixed and PS premixture blends due to lower affinity of CB to PMMA.…”

“…Pronounced suppression of structure coarsening during annealing was observed in filled co-continuous blends with selective M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 3 localization of the filler particles in one component or at the interface [12][13][14].…”

Porous fibers surface decorated with nanofillers: From melt‐spun PP/PVA blend fibers with silica nanoparticles

“…6,7 In some cases, several approaches are combined to get rid of the drawbacks of a single method. A large number of water-soluble polymers are available as sacrificial polymers, such as polyvinyl alcohol (PVA), 10,11 poly(ethylene oxide), [12][13][14] polyvinylpyrrolidone, 15 and sulfopolyester 16,17 to avoid any toxicity problem during the process. Among the technologies, melt blending is a nonsolvent, cost-effective, and highly efficient process.…”

Effect of a dual compatibilizer on the formation of co-continuous morphology of immiscible po`lymer blends

“…Co-continuous blends can also be used to generate porous materials by extraction of one of the phases with a selective solvent, yielding a self-supporting scaffold of the remaining material [1][2][3][4][5][6][7][8][9][10]. However, co-continuous morphologies are kinetically trapped and thermodynamically unstable structures that coarsen during annealing [11,12]. Many factors may affect the formation and stability of co-continuous morphology in polymer blends.…”

“…Some of them are processing conditions [14][15][16], viscosity or viscosity ratio [17,18], blend composition [13,19], shear intensity [20], interfacial tension [21,22], interfacial behaviors [23], compatibilizers (e.g. block copolymers [24][25][26][27][28] or graft copolymer [29][30][31][32][33][34][35], and inorganic nanoparticles such as nanoclay [12,36,37] and carbon nanotubes [38,39]). For immiscible polymer pairs, adding premade copolymers as compatibilizers is an effective way to reduce the interfacial tension [21,40].…”