Nowadays, various commercial polymers such as low density poly(ethylene) (LDPE), poly(propylene) (PP), and Nylon, may contain or are fabricated with molecular and/or nano-sized inorganic filler... Show moreNowadays, various commercial polymers such as low density poly(ethylene) (LDPE), poly(propylene) (PP), and Nylon, may contain or are fabricated with molecular and/or nano-sized inorganic filler elements. These fillers elements often modify, enhance or bring desired changes to the native properties of these polymers. However, these additives also have the potential to interact with the physical environment. For any new additive, it is important to assess and evaluate the potential consumer exposure under intended conditions of use. This thesis reports on the preparation of model polymer samples fabricated with various molecular and nano-sized filler elements (exfoliated clays, quantum dots, and organic colorants) to help evaluate factors affecting the rate of migration and the potential consumer exposure associated with these materials. One of the main aims of this project is the development of methods to incorporate organic and inorganic additives into polymers relevant to food packaging and medical devices using a laboratory scale twin-screw micro-compounder. Some of the samples prepared via optimized methods include (1) 1, 3, 5, and 7 wt.% Montmorillonite in LDPE; (2) quantum dots (QDs) spanning a size range of 3-8 nm into LDPE; and (3) 1-2 wt.% colorant-loaded polymer films, where the colorants include phthalocyanine blue, phthalocyanine green, quinizarin blue, manganese (II) phthalocyanine and titanium (IV) oxide, and the host polymers include poly(propylene), poly(carbonate), Nylon 12, and PEBAX (poly(ether-block-amide)). In addition to optimizing methods for composite fabrication, the properties of these materials were analyzed using many techniques, including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and Fourier transform-infrared (FT-IR) spectroscopy. Migration experiments were carried out to evaluate the interaction of samples with model food and environmental systems. This research was instrumental to support efforts to understand the mechanisms of potential exposure to polymer additives. Show less
