Supramolecular shape memory polymers properties

Thermally-induced properties of supramolecular shape memory polymers containing pyridine... 

Abstract This chapter introduces the moisture-induced shape memory effect (SME) observed in supramolecular shape memory polymers, particularly shape memory polyurethane (SMPU), containing pyridine moieties. The moisture absorption of polyurethane networks containing pyridine moeties (PUPy) is discussed followed by an investigation into the effect of relative humidity (RH), temperature, BINA content and MDI-BDO content. The induence of moisture absorption on both the thermal properties and the dynamic mechanical properties of SMPUs is also described, along with the moisture-induced SME mechanism. 

In more recent times, the possibilities enabled by utilising the reversible nature [11] of supramolecular interactions has resulted in their introduction into materials chemistry [12, 13]. The driving force for such studies is that the strength of supramolecular interactions can be reversibly altered by application of external stimuli. In the case of materials chemistry, this means that a physical property of the material (for example, its tensile strength) can be changed in real time and in situ. This feature has transformative potential in numerous applications, including those as healable materials [14-24] and shape-memory polymers [25-28]. 

The main-chain type pyridine containing SMPU has so far not been fully investigated. In future studies, the pyridine ring will be attached to the polymer backbone as a pendant. Based on the hydrogen-bonded supramolecular stmcture, the BIN-SMPUs will have maity unique advantages due to their shape memory, mechanical and damping properties. 

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