Thesis Type: Doctorate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2014
Student: BURCU ŞENGÜL
Supervisor: NURSEL DİLSİZ
Abstract:Poly(lactic acid)/layered silicate nanocomposite films, intended to use as a food contact material, were prepared by solution casting technique. Halloysite, bentonite and four types of organo-modified montmorillonite were used for the preperation of nanocomposites as inorganic filler. The structural characterizations of the nanocomposite films were performed by FTIR/ATR and dispersion of the layered silicates in the polymer matrix was characterized by XRD. Clay layers were found to be dispersed in the polymer matrix, although agglomerated particles were also detected by XRD. DSC was performed to study the thermal behaviour of the prepared films. The surface properties of the films were investigated with static and dynamic contact angle measurements and AFM analysis. The viscoelastic properties of the films were determined by using DMA. Water vapor and oxygen gas permeability of the nanocomposite films were decreased up to 80% and 49 %, respectively when compared to neat PLA film. The risks of nanocomposite films, over consumer and environmental safety are outlined with overall migration tests. Overall migration test results showed that it is safe to use the nanocomposite films prepared as food contact materials. It is determined that PM24 nanocomposites gave the best oxygen barrier property and migration values due to the compatibility between M24 clay and PLA. The biodegradability of prepared films was studied under compost and monitored by using Raman Spectroscpoy firstly in this study. It is observed that the rate of biodegradation was increased with clay loading.