No abstract

Polymer-nanocomposites based on sustainable fillers are integral to the development of modern high-performance materials. Consequently, the successful preparation of Montmorillonite (MMT)polymer-nanocomposites with tailorable mechanical properties via surface grafting of RAFT polymers was established. Strategies to precisely tune the properties of filler-matrix and matrix-free composites were developed and characterized via tensile testing. The possible application of these approaches for the synthesis composites with enhanced gas barrier properties was explored.The naturally occurring layered silicate MMT was modified with an ionic monomer for radical polymerization via an ion exchange procedure and subsequently employed in a grafting through RAFTpolymerization of methyl acrylate. The successful surface modification with monomer and polymer was demonstrated with a variety of methods. Thermogravimetric analysis (TGA) and elemental analysis (EA) both showed a significant increase of organic content after modification. attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy was used to demonstrate the presence of all components (MMT, surface grafted monomer, and polymer) in the resulting composites. scanning near-field optical microscopy (s-SNOM) allowed for the proof that a significant amount of polymer can be immobilized at the surface while any unbound polymer can be separated from the sample. Hence, the production 3.1. Methods used throughout this thesis S Z S R Scheme 3.1: Schematic structure of a RAFT agent. 42 Scheme 3.2: General mechanism of a RAFT polymerization. 42 Blue balls represent monomer units.