PRODUCTION AND CHARACTERIZATION OF UREA AND SUCCINIC ACID COPOLYMERS PRODUCED VIAPOLYMERIZATION IN SOLUTION AND MECHANICAL CHEMISTRY
Urea, copolymers, polymerization, mechanochemistry
Urea-based polymers have several applications, such as in the manufacture of paints, glues, drugs, plastics, paper and coatings. In this sense, this doctoral thesis aims to develop a process for the production of new urea-based polymeric materials in both aqueous and solvent-free mechanically. The monomers used are urea (U), succinic acid (AS), as well as ethylene glycol (EG) and glycerol (GLI) as a branching and / or crosslinker. The development of the process was based on previous work of the Polymer and Bioprocess Laboratory Research Group (LPB / UFBA), and initially a classical approach using a wet polymerization route was chosen. The initial study aimed to analyze the structural, chemical and thermal properties of U / AS / EG and U / AS / GLI copolymers produced in aqueous solutions with different compositions. Fourier transform infrared spectroscopy (FTIR / ATR) analyzes, matrix assisted laser desorption ionization process - flight time (MALDI TOF), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), exploratory calorimetry Differential (DSC) and X-ray diffraction (XRD) allowed to evaluate the changes caused by the insertion of EG and GLI in the U / AS matrix chains, such as molar mass, thermal stability and crystallinity. Polymerization was also carried out by mechanical means, using a planetary ball mill. An unprecedented approach to this type of polycondensation. The obtained samples were analyzed by FTIR / ATR, electrospray ionization mass spectrometry (ESI-MS), MALDI TOF, NMR, TGA and DSC. The results confirmed that the reactions were successfully performed and materials with similar characteristics produced in solution were obtained, with low energy cost and without the use of organic solvents.