Study on effect of the clay size on the dispersion morphology and emulsion stability of abs/layered silicate nanocomposites

Abstract

In this dissertation, polymer/layered silicate nanocomposites were prepared via in-situ emulsion polymerization using amphiphiles. The polymer selected for this study were ABS (acrylonitrile-butadiene-styrene) copolymer. The dispersion morphology and emulsion stability of the nanocomposites were researched. Water-soluble PVP/MMT nanocomposites were prepared via solution intercalation method. The d spacing of Na-MMT layers were expanded. The result could be assisted by the hydrogen bonding interaction between C=O of PVP and OH on the silicate surface. And ABS/MMT nanocomposites were synthesized via emulsion polymerization. ABS/MMT nanocomposites showed no peak on XRD pattern. From the result, the nanocomposites were exfoliated. Exfoliated ABS/MMT nanocomposites were synthesized via emulsion polymerization. PVP helps the silicates to be exfoliated. ABS/layered silicate nanocomposites were synthesized through an emulsion polymerization with different sizes of silicates. The particle sizes of Laponite, Cloisite-Na and Kunipia-F are about 20~30 nm, 70~150 nm and 300~500 nm, respectively. When ABS was synthesized by the emulsion polymerization in the presence of Laponite and Cloisite-Na, ABS/layered silicate nanocomposite emulsion showed a stable suspension without the precipitation of solid particle. On the other hand, ABS/layered silicate nanocomposite synthesized with Kunipia-F showed the precipitation of large aggregated particles and the phase separation. Smaller sizes of silicates like Laponite and Cloisite-Na than polymerized particle worked as resided barrier preventing the emulsion particle from coagulation. Larger size of silicate like Kunipia-F than emulsion particle was not able to enclose the emulsion particle delicately because of its stiffness and large aspect ratio. The monomers inserted into the intercalated Kunipia-F connected the ABS particles and clay particles. The Kunipia-F particles anchored ABS particles around them inducing the aggreg...