Structural Modification of triacylglycerols to obtain monomers and polymers following Principles of Green Chemistry: Efficient synthetic pathways with less energy spending.

Author(s)

Rafael Turra Alarcon

• Document type: Doctoral Thesis
• Press: Bauru. 2022-05-24.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências. Bauru
• Defense date: 2022-05-06
• Advisor: Gilbert Bannach

Abstract

Researches have been improving new polymeric synthetic routes using renewable chemicals. The vegetable oil is an excellent example of a renewable chemical, which can be easily extracted and modified to be applied in the polymer field. However, the use of a renewable chemical is not enough; therefore, researchers have been looking for cleaner and efficient synthetic routes. Thus, the twelve Principles of Green chemistry can assist these researches. One principle describes that experiment should be performed at room temperature not to expend energy; however, some reactions do not occur at room temperature even using correct catalysts. It is therefore necessary to use new efficient energetic systems such as microwave irradiation and light (photochemistry) not to use conventional thermal routes. As consequence, some triacylglycerols were modified by microwave irradiation to synthesize new monomer, which were used in polymers production by photochemistry process. Therefore, triacylglycerols were chemical modified by microwave irradiation to synthesize maleinized oils. These presented 54% more incorporation o anhydride to those synthesized by a conventional thermal route, in only 15 minutes. The synthetic route by microwave irradiation has exhibited a cleaner and more efficient process than the conventional thermal route. Furthermore, maleinized oils were reacted with diethyleneglycol or glycerol to obtain polymers that displays luminescence under UV light, due to the Agreggation-induced Emission-AIE; the reaction was fast without catalyst. Triacylglycerols of baru and macaw were epoxidized in an efficient manner using a heterogeneous catalyst (Amberlite IR-120). Thereafter, these were reacted with CO2 in the presence of an aluminium catalyst to provide carbonated triacyclglycerols with a carbonate conversion of ≥99,9. These carbonated triacyclglycerols were further reacted with diamines to obtain polyhydroxyurethanes, which exhibited self-healing properties under a red light (660 nm). Moreover, the epoxidized triacylglycerol of macaw was reacted with acrylic acid to synthesize acrylated oils. This acrylated oil exhibits self-polymerization under UV light without presence of a coinitiator, which is a promising monomer to be used in 3D printers. All polymeric material were characterized by Simultaneous Thermogravimetry- Differential Thermal Analysis and Differential Scanning Calorimetry to determine their thermal stabilities, degradation steps and glass transition. The techniques such as Mid-Infrared Spectroscopy (MIR) and Nuclear Magnetic Resonance (1H-RMN e 13C-RMN) were used to understand the chemical and structural changes in these vegetable oils. (AU)

• FAPESP's process: 18/03460-6 - Structural modification of triglycerides aiming new monomers and polymers, using different synthetic routes: microwave irradiation and photopolymerization
• Grantee: Rafael Turra Alarcon
• Support Opportunities: Scholarships in Brazil - Doctorate