Preparation of polystyrene–clay nanocomposites via dispersion polymerization using oligomeric styrene‐montmorillonite as stabilizer |
| |
Authors: | Nagi Greesh Ronald Sanderson Patrice Hartmann |
| |
Affiliation: | 1. Department of Chemistry and Polymer Science, UNESCO Associated Centre for Macromolecules, University of Stellenbosch, Private Bag X1, 7602 Matieland, South Africa;2. Mondi Packaging South Africa, Research and Development Center, Bosman Street, Paul Sauer Building, 7599 Stellenbosch, South Africa |
| |
Abstract: | This study describes the preparation of polystyrene–clay nanocomposite (PS‐nanocomposite) colloidal particles via free‐radical polymerization in dispersion. Montmorillonite clay (MMT) was pre‐modified using different concentrations of cationic styrene oligomeric (‘PS‐cationic’), and the subsequent modified PS‐MMT was used as stabilizer in the dispersion polymerization of styrene. The main objective of this study was to use the clay platelets as fillers to improve the thermal and mechanical properties of the final PS‐nanocomposites and as steric stabilizers in dispersion polymerization after modification with PS‐cationic. The correlation between the degree of clay modification and the morphology of the colloidal PS particles was investigated. The clay platelets were found to be encapsulated inside PS latex only when the clay surface was rendered highly hydrophobic, and stable polymer latex was obtained. The morphology of PS‐nanocomposite material (after film formation) was found to range from partially exfoliated to intercalated structure depending on the percentage of PS‐MMT loading. The impact of the modified clay loading on the monomer conversion, the polymer molecular weight, the thermal stability and the thermomechanical properties of the final PS‐nanocomposites was determined. Copyright © 2012 Society of Chemical Industry |
| |
Keywords: | dispersion polymerization nanocomposites encapsulation clay modification intercalated exfoliated |
|
|