Influence of polarity on the preferential intercalation behavior of clay in immiscible polypropylene/polystyrene blend

Abstract

The immiscible polypropylene (PP)/polystyrene (PS) blend was prepared via melt compounding and the preferential intercalation behavior of clay was investigated by wide angle X-ray diffraction (XRD) and transmission electron microscope (TEM). It was found that the clay platelets initially located in the PS phase in PP/ PS/Clay composites and PS chains intercalated into the clay layers. However, all clay migrated from the PS phase to the modified PP phase after introducing polar maleic anhydride group (MAH) to PP chains. Interestingly, most of clay migrated from the modified PP phase to the modified PS phase again when PS matrix was modified with sulfonic group, and some enriched in the interphase region. The interaction energy density (B) of the blends was determined by combining the melting point variation with the ternary interaction model for heat of mixing. It was found that the value of B decreased with the introduction of polar group (MAH or sulfonic group), indicating that the polarization of PP and PS can enhance interaction between clay platelet and polymer component. Different interaction between clay platelet and polymer component leads to the preferential intercalation behavior. The higher polarity of the polymer generates higher interaction between clay and polymer component as well as results in stronger preferential intercalating ability. Moreover, the results of FTIR spectra after extraction of all samples gave additional explanation of the preferential intercalation behavior of clay in the immiscible PP/PS blends. On the basis of the results of the measurement mentioned above, a possible mechanism was proposed.

Polymer blend nanocomposites: effect of mercapto silane modified kaolin clay on the thermal properties of Polypropylene/Polystyrene blend

“…The insertion of organoclay in polymer blends significantly changes the structure, typically decreasing the size of the dispersed phase. The location and the degree of dispersion of clay influence the thermal and mechanical properties of polymer blend/clay nanocomposites …”

Polypropylene/combinational inorganic filler micro‐/nanocomposites: Synergistic effects of micro‐/nanoscale combinational inorganic fillers on their mechanical properties

“…Interfacial adhesion of various components is one of the most important factors, and an adequate adhesion strength is vital to mechanical properties of polymer composites 28, 29, 45‐47. Coupling agents, compatibilizers, and irradiation grafting polymerization have been usually used to modify the surfaces of inorganic fillers and consequently to enhance the affinity and bonding strength between inorganic fillers and organic matrices 11, 18, 23, 33, 34, 38–49. Particle sizes and morphologies of inorganic fillers are also found to be important factors that influence the properties of polymer composites 20–24, 31, 32, 41, 42, 50, 51.…”

“…In addition, uniform dispersion of the filler particles in polymer matrices has been a precondition of achieving an effective reinforcement 39. On the basis of the literature survey, inorganic fillers with singular species are widely used to reinforce polymer‐matrix composites,13–24, 40–46 whereas the combinational inorganic fillers (CIFs), consisting of various species of particles with different morphologies and different size‐distributions, have seldom been designed to modify polymer composites 50–54…”

“…9,11,[33][34][35][36][37] Nanocrystalline inorganic fillers (i.e., carbon nanotubes, nano-SiO 2 , nano-CaCO 3 , and organoclays) have been extensively investigated to modify polymers, and a number of reports indicate that small amounts of nanocrystalline fillers can strengthen, toughen, and functionalize PP-matrix materials. 2,14,32,[38][39][40][41][42][43][44][45][46][47][48] But there are two big challenges in reinforcing polymer-matrix materials with nanocrystalline fillers: one is the uniform dispersion of nanocrystals in polymer matrix and the other is the high costs. 39,49 To the best of our knowledge, there have been no efficient routes to solve these problems yet.…”

“…28,29,[45][46][47] Coupling agents, compatibilizers, and irradiation grafting polymerization have been usually used to modify the surfaces of inorganic fillers and consequently to enhance the affinity and bonding strength between inorganic fillers and organic matrices. 11,18,23,33,34,[38][39][40][41][42][43][44][45][46][47][48][49] Particle sizes and morphologies of inorganic fillers are also found to be important factors that influence the properties of polymer composites. [20][21][22][23][24]31,32,41,42,50,51 In addition, uniform dispersion of the filler particles in polymer matrices has been a precondition of achieving an effective reinforcement.…”