We report the synthesis and characterization of a new linear polyphosphazene architecture in which rigid, bulky side units provide the possibility of interdigitation with their counterparts on neighboring chains to generate noncovalent cross-links and distinct elastomeric properties. The bulky side groups are cyclotriphosphazene rings substituted with trifluoroethoxy groups connected to the main chain via aryloxy spacers. These bulky units are distributed along the polymer backbone and separated from each other by trifluoroethoxy units linked directly to the main chain. Compared to the well-known poly[(bis-2,2,2-trifluoroethoxy)phosphazene], [NP(OCH2CF3)2]n, which is a microcrystalline film- and fiber-forming polymer, several of the new materials are elastomers with properties that arise partly from interactions of the protruding cyclotriphosphazene side units with those on nearby polymer chains. Specific elastomers are capable of regaining up to 89% of their original shape when elongated to high strain (up to 1000%) over four elongation cycles and show even longer elongations at break (>1600%). The overall physical properties depend on the ratios of the cyclic trimeric side units to main chain linked trifluoroethoxy side groups. The polymers were characterized using 1H, 31P NMR, DSC, TGA, X-ray diffraction, GPC, and stress-strain techniques.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry