Date of Award
Master of Science in Chemical Engineering (MSChE)
Chemical and Petroleum Engineering
Dr. Muhammad Zafar Iqbal
With increasing stringent environmental regulations and attempts to reduce dependence on fossil fuels for polymer production, bio-based polymers are receiving appreciable global attention. In this context, bio-based poly (lactic acid) (PLA) is one of the most frequently used polymers in packaging applications. However, despite of its high versatility, this polymer is limited in packaging applications due to its low mechanical properties. The two-dimensional nanofillers such as nanoclay and graphene are well known for improving the thermo-mechanical properties of polymers at low concentrations. However, increasing higher filler concentration to improve barrier properties of polymers reduces their mechanical properties which is a drawback. This thesis investigates the effects of two-dimensional nanoclays on the thermal, mechanical, and barrier properties of PLA/clay nanocomposites.
The nanocomposites of PLA with clay and chemically modified clay were synthesized via the solution blending method, and their thermal and mechanical properties were investigated. Several characterization techniques were used to understand the chemical structure of nanoclays and the thermophysical properties of PLA/clay nanocomposites. The x-ray diffraction indicated increased dispersion and exfoliation of modified clay in PLA compared to unmodified clay. A significant decrease in percent crystallinity of PLA-modified clay nanocomposites was observed. A higher Young’s modulus and yield strength and reduced elongation at break revealed increased filler/polymer interactions in PLA/modified clay nanocomposites. Moreover, results from gas permeability revealed 75% reduction in Nitrogen gas permeability for PLA/Modified nanocomposites at 5wt%. The results could be used as a fundamental understanding of clay/PLA interactions for thin-film packaging applications. However, a detailed analysis of extensional rheology is required to assess the feasibility of these nanocomposites for film blowing applications.
Akram Adi, Maissa, "POLY (LACTIC ACID)/NANOCLAY NANOCOMPOSITES FOR PACKAGING APPLICATIONS" (2020). Theses. 815.