Date of Award
Master of Science (MS)
Dr. Ram Gupta
Dr. Charles Neef
Dr. Timothy Dawsey
Dr. John Franklin
The use of renewable resources in film formation has become a new focal point for industry because it is abundantly available and has less carbon emission during production than traditional ones. This has drawn researchers to investigate the functionality of bio-based raw materials and their end-usage. By modifying their chemical structures, the properties of these films like thermal resistance, impact resistance, and chemical resistance can be increased. In this research, limonene was used as a partial replacement for petroleum-based chemicals in film formation. A two-step chemical process was carried out to modify the limonene and the final product was used in film formulations. Titration and Fourier transform infrared spectroscopy (FTIR) analysis were used to confirm the structure of the modified limonene. The UV-cured films were also analyzed by tensile, flexural, hardness, and thermal tests to examine their mechanical and thermal properties.
Limonene oil was modified using a thiol-ene reaction to introduce hydroxyl functionality to prepare a limonene diol (LD). Then, a methacrylation reaction was carried out to synthesize methacrylated limonene diol (MaLD) with a byproduct of methacrylic acid and this mixture is referred to as ML-Ma. To prepare a solution of bio-based modified films (BMF), methacrylic acid (MA) was used as a reactive diluent, 2,2-dimethoxy-2-phenylacetophenone (DMPA) as a photoinitiator, and tetra (ethylene glycol) diacrylate (TEGDA) as a cross-linker. They were added to the ML-Ma before curing with UV radiation. By examining the intensity of the C=C peak appearing at 1635 cm-1 in the FTIR spectrum, the approximate curing percentage was calculated. A methyl ethyl ketone (MEK) rub test was also conducted to check the crosslinking of the UV-cured sample.
The BMF films were prepared with varying amounts of bio-based content ranging from 0 wt. % to 55 wt. % (BMF-0 to BMF-55) to reduce the amount of commercial cross-linker (TEGDA). The UV-cured films were investigated to study their mechanical and thermal properties. Good results were obtained using 30 wt. % of ML-Ma (BMF-30). An increase in tensile strength, hardness, and flexural characteristics was observed. The variation in the amounts of TEGDA and ML-Ma showed the bio-content needed to optimize the mechanical properties of the film. As a result of this study, it was found that commercial products TEGDA cross-linker can be partially replaced by modified bio-based content of ML-Ma with increasing the overall mechanical properties of the films.
CHAUDHARY, SAHILKUMAR, "BIO-BASED UV-CURABLE FILMS AND THE EFFECT OF BIO-CONTENT ON THE PROPERTIES OF THE FILMS" (2022). Electronic Theses & Dissertations. 400.