Tekstil substratları üzerine kaplama uygulamaları için su esaslı anyonik poliüretan ve akrilat aşılanmış poliüretan dispersiyonlarının hazırlanması

Aqueous polyurethane dispersions (PUDs) provide excellent impact and abrasion resistance to the materials by forming films on their surface. For this reason, they have wide range of applications in textile, adhesive, and wood coating industries. Aqueous PUDs are defined as binary colloidal systems in which the PU particles are dispersed in a continuous aqueous medium. However, in order to disperse water immiscible PU polymer chains in water, ionic and/or nonionic hydrophilic segments should be associated with the conventional PU structure. Therefore, PUDs are generally prepared by dispersing isocyanate terminated PU prepolymers, in the aqueous systems consisting of colloidal stabilizers. Preparing hybrid PU/polyacrylate (PAc) colloidal systems by mixing aqueous PUDs with polyacrylates (PAc), on the other hand, could be a favourable approach for the improvement of mechanical and chemical resistance of the coating materials. However, poor compatibility between PAc and PU components could cause the loss of film properties most of the time. In such case, chemical bonding between PU and PAc chains could be used as a versatile approach for obtaining hybrid systems exhibiting excellent properties of both kinds. With this thesis, by using aliphatic isocyanates and difunctional polyesters, solvent-free PUDs having 25-30% of solid content were prepared through acetone process. Afterwards, in order to introduce vinyl functionality, resulting PU prepolymers were reacted with a hydroxyl functional acrylate monomer. Then PAc grafting on the PU chains was achieved by seeded emulsion polymerization between the vinyl functional PU chains and acrylate monomers. Additionally an acylate emulsion was obtained via emulsion polymerization of butylacrylate (BA), ethylacrylate (EA) and hydroxyetyl acrylate (HEA) in order to characterize hybrids more accuretly. Chemical structures of the resulting materials were characterized by Fourier Transform Infrared (FTIR) spectroscopy. Moreover, solid content, pH, viscosity, particle size distribution, and stability of the resulting dispersions were also studied. On the other hand, thermal properties of the films prepared from the obtained dispersions were also investigated by using Diferantial Scanning Caloremetry (DSC), while mechanical properites were determined in terms of Shore A hardness and tensile strength. In the end, application properties of resulting materials in textile industry were examined by investigating the final properties of coated textile substrates.