Shape Memory Polymer Based On Polyvinyl Alcohol

Polyvinyl alcohol (PVA) is a type of easy-processable and biocompatible shapememory polymer (SMP). For PVA based SMPs, the cross-linked network andundisturbed crystal domain contribute to the permanent phase, while the amorphousphase acts as the temperature sensitive phase. Its strength and shape memory behaviorcould be designed by changing its cross-linked degree and the incorporation of fillers. Inthis paper, several works about SMPs based on PVA had been done through the followingaspects.Firstly, PVA SMP with different cross-linked degree were successfully prepared byadding different contents of glutaraldehyde, of which the mechanical behavior,thermodynamic property and thermal induced shape memory properties were studied.Compared with the pure PVA, the cross-linked PVA showed excellent mechanicalstrength and shape memory effect. The cross-linked PVA sample containing3wt.%glutaraldehyde could completely recovery to its original shape in50s and its tensilestrength increased by1418%.Then specimens of acidic multi-walled carbon nanotubes (AMWNTs) reinforcedpolyvinyl alcohol (PVA) nanocomposites (AMWNTs-PVA) were prepared using differentamounts of AMWNTs by the traditional solution casting, involving ultrasonic waveagitation. AMWNTs had good compatibility with PVA and dispersed evenly in the PVAmatrix. The incorporation of AMWNTs improved the tensile modulus, strength,conductive capacity and thermal conductivity of the PVA. The thermal induced shaperecovery testing revealed that the recovery ratio increased and the shape recovery rateslightly decreased with the increase of AMWNTs content. The electric induced shaperecovery testing showed that with the increase of AMWNTs, the complete recoverydriven voltage decreased. As well as with the driven voltage increased, the recovery ratioincreased and the shape recovery rate increased.And finally specimens of polyaniline doped with camphorsulfonic acid (PANI-CSA)reinforced polyvinyl alcohol (PVA) nanocomposites were prepared, and the conductive capacity, thermal conductivity as well as electric induced shape memory effect wereinvestigated.