Temperature-responsive polymers properties, synthesis and applications

Abstract This chapter describes polymers that undergo a temperature-induced phase transition in aqueous solution providing an important basis for smart materials. Different types of temperature-responsive polymers, including shape-memory materials, hquid crystalline materials and responsive polymer solutions are briefly introduced. Subsequently this chapter will focus on thermoresponsive polymer solutions. At first, the basic principles of the upper and lower critical temperature polymer phase transitions will be discussed, followed by an overview and discussion of important aspects of various key types of such temperature-responsive polymers. Finally, selected potential apphcations of thermoresponsive polymer solutions will be described. [Pg.15]

Key words smart material, responsive polymer, lower critical solution temperature (LCST), upper critical solution temperature (UCST),phase transition. [Pg.15]

Temperature-responsive polymers are especially interesting since variations in temperature can be applied externally in a non-invasive manner. Furthermore, spontaneous temperature fluctuations also occur in nature, for example, during day and night cycles as well as the increased temperature of inflamed tissue. Different working mechanisms can be exploited for the development of temperature-responsive polymers as will be briefly outlined in this introductory paragraph. The three main classes of temperature-responsive polymers are [Pg.16]

1 Schematic representation of the thermoresponsive behavior of a shape-memory polymer. 7 represents the 7 of the hard phase and 71 represents the 71 of the switching phase. [Pg.16]

2 (a) Change in conformations of main-chain LC polymers from the extended nematic phase to a collapsed isotropic phase upon heating, (b) Corresponding macroscopic shape change during this nematic-isotropic phase transition. [Pg.17]