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Influence of arm length and number on star-shaped poly(2-isopropyl-2-oxazoline) aggregation in aqueous solutions near cloud point |
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| Authors: | Alina I Amirova Olga V Golub Tatyana U Kirila Alla B Razina Andrey V Tenkovtsev Alexander P Filippov |
| Institution: | 1. Institute of Macromolecular Compounds of Russian Academy of Sciences, Saint Petersburg, Russiaaliram.new@gmail.com;3. Institute of Macromolecular Compounds of Russian Academy of Sciences, Saint Petersburg, Russia;4. Saint Petersburg University, Saint Petersburg State University, Saint Petersburg, Russia |
| Abstract: | Four-arm star-shaped poly(2-isopropyl-2-oxazolines) (PiPrOx4) are synthesized by cationic polymerization on t-butylcalix4]arene macroinitiator. The obtained samples differ by polymerization degree of arms NPiPrOx = 9 and 25 and are characterized in chloroform. The behavior in aqueous solutions is studied by light scattering methods and compared with the results of investigation of eight-arm star with similar structure. Three types of particles are observed in solution of short-arm PiPrOx4 at room temperature, whereas only two particle types are present in long-arm star solution. Arm shortening leads to widening of the phase transition interval. The arm number decreasing reduces the phase transition temperature by 1°C. |
| Keywords: | Aggregation light scattering solution properties star polymers stimuli-sensitive polymers |