SMPU/POSS nanocomposite

The nanocomposites were elastic at temperatures above the Tg of PDLLA-domains as determined by DMTA measurements. The SMPU/POSS nanocomposites had storage tensile moduli greater than 2GPa at low temperatures (see Fig. 15a). The modulus dropped to a value of about lOMPa upon heating above Tg of the switching domains. This rubbery plateau bridged the temperature range from PDLLA domains associated T and POSS related Tm. Pure SMPU without POSS... 

Fig. 14 Chemical formula of the obtained SMPU/POSS nanocomposite. Reprinted with permission from [117]. Copyright 2008, American Chemical Society...

Fig. 15 Thermomechanical properties of SMPU/POSS nanocomposites, (a) Storage tensile modulus and tanS depending on temperature for SMPU with different POSS/polyol ratios (i) 0, (ii) 0.98, (iii) 1.67, and (iv) 2.63. (b) Cyclic thermomechanical tests for SMPU/POSS (POSS/polyol = 2.623). Three cycles are shown (solid line) first cycle, (broken line) second cycle, and (dotted line) third cycle. The asterisk marks the beginning of the cycle and the arrows denote the various stages, specifically (1) deformation, (2) cooling/fixing, (3) unloading, and (4) recovery. Reprinted with permission from [117], Copyright 2008, American Chemical Society...

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