Temperature responsive polymers able to alter their chemical or physical properties have been extensively investigated. Most of these polymers have an alkane polymer backbone with only carbon-carbon bonds. In this sense, the design of thermoresponsive polymers not only with sharp transition temperatures but also possessing hydrolizable linkages such as esters, carbonates or urethanes in the main backbone are highly desired. Here we show a library of thermoresponsive cationic and anionic polyurethanes synthesized by copolymerization of isophorone diisocyanate with poly(ethylene glycol) and ionic diols. These polyurethanes exhibit lower critical solution temperatures (LCST) that can be easily tuned from 20 °C to 60 °C by altering the polyurethane composition. Our findings show that LCST temperature could be reduced by the using poly(ethylene glycol) of lower molecular weight and/or increasing the hydrophobicity of the employed ionic diol. We also demonstrated that the thermoresponsive behavior could be translated to hydrogels based on those ionic polyurethanes. These "a la carte" This is a postprint of an article published by Elsevier . The final version of Ludmila

-In miniemulsion polymerization, droplet nucleation is the key factor to ensure the production of polymer particles with a desired composition. The influence of the initiation on droplet nucleation is conflicting and it has not been completely considered. The result of employing different initiator systems on the nucleation mechanism and kinetics in the polymerization of stable styrene/polystyrene miniemulsions with varied droplet size is discussed here. The initiation systems employed provide all combinations between the phase (aqueous or organic) where initiation mainly occurs and the phase affinity of the produced radicals. Latexes with different contributions of droplet nucleation were synthesized according to the employed initiation system and the droplet size of the miniemulsion. The results presented here could be used as a guide for choosing the initiation system to achieve the required contribution of droplet nucleation.