Synthesis and characterization of UV-curable linear and branched urethane acrylate resins

In this thesis, a series of linear and branched polyurethane acrylate oligomers were synthesized using different isocyanates and diol/triol structures. In the synthesis of polyurethane prepolymers, PEG400 and PEG1000 for linears and trimethylol propane (TMP) for branched structures were used as soft segments. The hard segment of polyurethane prepolymers is formed with hexamethylene diisocyanate (HDI) or toluene diisocyanate (TDI). In the next step, polyurethane acrylate oligomers were obtained by capping the active isocyanate terminals of the polyurethane prepolymers with Setalux and/or 2-hydroxyethyl methacrylate (HEMA). Changes in the chemical structure, thermal behavior, microphase behavior, microstructure, surface and film properties of the linear and branched polyurethane acrylate oligomers were determined by changing the HEMA/Setalux molar ratios. The microphase separation properties of polyurethane acrylate oligomers have been investigated by FT-IR band analysis of the C=O streching vibration using a deconvolution method by Origin software. In the next step of the thesis, UV curing studies were carried out with the addition of reactive diluent using some of the linear and branched polyurethane acrylate oligomers. The effect on curing was investigated by using different amounts of HEMA by weight as the reactive diluent. FT-IR, 1H-NMR, TGA, DSC, SEM analysis techniques and gloss and contact angle measurements were used to investigate some chemical and physical properties of the obtained polyurethane acrylate oligomers and UV cured films. Within the scope of this thesis, the effects of hard segment structure, soft segment structure and reactive diluent amounts on the properties of UV curable acrylate oligomers and their cured films were systematically examined and it was aimed to make significant contributions to the literature and related application areas.