Study on synthesis of polymer/layered silicate nanocomposites using reactive amphiphiles and their characterization

Abstract

In this dissertation, we prepared two types of polymer/layered silicate nanocomposites via in-situ emulsion polymerization using reactive amphiphiles. The polymers selected for this study were ABS (acrylonitrile-butadiene-styrene) copolymer and PS (polystyrene). The effect of the hydrophobic chain length within reactive amphiphiles on the dispersion state of silicates through polymer matrix was mainly investigated. According to that, the morphology and thermal stability of the nanocomposites were also researched. In chapter 2, Acrylonitrile-butadiene-styrene copolymer (ABS)/layered silicate nanocomposites were synthesized by in-situ emulsion polymerization to investigate the role of reactive amphiphiles on the silicate dispersibility. Three reactive amphiphiles with different hydrophobic chain lengths were synthesized. When short hydrophobic chain reactive amphiphiles were used, the nanocomposites showed intercalated states of silicates. But for the long chain amphiphiles, the silicates were exfoliated in ABS copolymer matrix. And we verified that silicate layers were attached on the rubber particles by using SEM and TEM tools. The nanocomposite exfoliated by using a longer amphiphile produced a slightly larger amount of residue than those by short amphiphiles and its decomposition temperature was also higher. Therefore it could be concluded that reactive amphiphiles played an important role in the dispersibility of silicate and the thermal property of ABS/layered silicate nanocomposite. In chapter 3, ABS/layered silicate nanocomposites were prepared through in-situ emulsion polymerization using three types of reactive amphiphiles. ABS/layered silicate nanocomposites obtained by using AMPS and DC14 as reactive amphiphiles showed exfoliated states of silicates. In the case of ABS/layered silicate nanocomposites made with MPTA and DC3, on the other hand, we confirmed that the silicates were intercalated in ABS matrix. And SDS made the emulsion more stabl...