New thermo-responsive graft copolymer s and hydrogelswere synthetized. The graft copolymer were synthesized bythe cationic ring-opening polymerizatio n of 2-methyl-2-oxazoline (MeOXA) , or 2-ethyl-2-oxazoline (EtOXA), respectively, initiated by the random copolymer s ofchloromethylstyren e (CMS) and N-isopropylacrylamide(NIPAAm) using the “grafting from” method with a yield of 66to 94%1. The polymers were characterized by NMR, GPC andDSC and the conformational transition (Lower Critical SolutionTemperature-LCST) of macroinitiators and graft copolymerswas determined by the turbidity and DSC measurements. Thetransition temperature of the graft copolymers could be finetunedthrough the composition of the macroinitiator and the graft copolymer. An increasing quantity of the hydrophobiccomonomer chloromethylstyrene in the macroinitiator lowered its LCST, while in the graft copolymer an inc...

New thermo-responsive graft copolymer s and hydrogelswere synthetized. The graft copolymer were synthesized bythe cationic ring-opening polymerizatio n of 2-methyl-2-oxazoline (MeOXA) , or 2-ethyl-2-oxazoline (EtOXA), respectively, initiated by the random copolymer s ofchloromethylstyren e (CMS) and N-isopropylacrylamide(NIPAAm) using the “grafting from” method with a yield of 66to 94%1. The polymers were characterized by NMR, GPC andDSC and the conformational transition (Lower Critical SolutionTemperature-LCST) of macroinitiators and graft copolymerswas determined by the turbidity and DSC measurements. Thetransition temperature of the graft copolymers could be finetunedthrough the composition of the macroinitiator and the graft copolymer. An increasing quantity of the hydrophobiccomonomer chloromethylstyrene in the macroinitiator lowered its LCST, while in the graft copolymer an inc...

New thermo-responsive graft copolymer s and hydrogelswere synthetized. The graft copolymer were synthesized bythe cationic ring-opening polymerizatio n of 2-methyl-2-oxazoline (MeOXA) , or 2-ethyl-2-oxazoline (EtOXA), respectively, initiated by the random copolymer s ofchloromethylstyren e (CMS) and N-isopropylacrylamide(NIPAAm) using the “grafting from” method with a yield of 66to 94%1. The polymers were characterized by NMR, GPC andDSC and the conformational transition (Lower Critical SolutionTemperature-LCST) of macroinitiators and graft copolymerswas determined by the turbidity and DSC measurements. Thetransition temperature of the graft copolymers could be finetunedthrough the composition of the macroinitiator and the graft copolymer. An increasing quantity of the hydrophobiccomonomer chloromethylstyrene in the macroinitiator lowered its LCST, while in the graft copolymer an inc...

New hydrogels were synthesized based on free radical polymerization of N-isopropylacrylamide (NiPAAm) and macromonomers of 2-oxazolines in presence of clay Laponite XLS (synthetic hectorite). The used macromonomers were statistical copolymers of 2-(2-methoxycarbonylethyl)- and 2-methyl-2-oxazoline, with a polymerization degree of 20 and 24 units and a content of 23 and 49 mol-% of 2-(2-methoxycarbonylethyl)-2-oxazoline, respectively, and had a vinyl group at the chain end. The hydrogel synthesis was carried out using ammonium persulfate (APS) and N,N,N,N-tetramethylethylendiamine (TEMED) as initiating system and Laponite XLS as crosslinker. After polymerization, the esters groups of the obtained hydrogels were hydrolized in situ to obtain carboxylic acids groups. Finally, hydrogels were obtained with high mechanical stability, transparency, and responsivity to temperature and pH. The hyd...