TY - JOUR TI - The effect of the polar solvents on the synthesis of poly(urethane-urea-siloxane)s AU - Balaban Milica AU - Antić Vesna AU - Pergal Marija AU - Francolini Iolanda AU - Martinelli Andrea AU - Đonlagić Jasna JN - Journal of the Serbian Chemical Society PY - 2012 VL - 77 IS - 10 SP - 1457 EP - 1481 PT- Article AB- Segmented poly(urethane-urea-siloxanes) (PUUS) based on 4,4’- methylene diphenyl diisocyanate-ethylene diamine (MDI-ED) hard segments and hidroxypropyl-terminated poly(dimethylsiloxane) (PDMS, M n =1000 g mol-1) soft segments were prepared under various experimental conditions. The copolymers with constant molar ratio of hard and soft segments (PDMS:MDI:ED = 1:2:1; 20 wt. % of the hard segments) were synthesized in two different solvent mixtures, by two-step polyaddition procedure. The first one was THF/DMAc with different co-solvent ratio (1/1, 1/2 and 1/9, v/v), whereas the second one was THF/NMP (1/9, v/v). The reaction conditions were optimized by varying the co-solvents ratio, the concentration of the catalyst, the initial monomer concentration, as well as the time of the first and the second step of reaction. The effect of the experimental conditions on the size of PUUS was investigated by gel permeation chromatography (GPC) and viscometry of the dilute solutions [η]. The copolymers with the highest molecular weights were obtained in the THF/NMP mixture (1/9, v/v). The structure and composition of the copolymers were determined by 1H NMR and FTIR spectroscopy. The morphology of the synthesized copolymers was investigated by atomic force microscopy (AFM), while the thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The surface properties were evaluated by measuring the water contact angle (WCA). The copolymers showed phase separated microstructure and were stable up to 200°C in nitrogen.