Microspheres prepared with a temperature‐responsive macromonomer

A macromonomer was prepared from succinimido methacrylate and poly(N‐isopropylacrylamide) (PIPA) with an amino end group. The macronomer (MA‐PIPA) obtained shows a temperature‐responsive transition phenomenon from coil to globule in water at about 36°C. For the copolymer of MA‐PIPA with acrylamide (ratio of monomer residues of N‐isopropylacrylamide (IPA) and acrylamide (AAm) 10:3), the transition temperature of the PIPA chain was the same as that of the macromonomer, whereas the transition temperature of a linear copolymer of IPA and AAm (ratio of the monomer residues 10:3) was much higher than that of PIPA (52°C). Microspheres were prepared by emulsion polymerization of the macromonomer and styrene in the presence of sodium dodecylsulfate. The microspheres obtained show a temperature responsiveness in the critical flocculation concentration. The macromonomer prepared here can be used as a component of temperature‐sensitive devices in various forms.