| The effect of bacterial cellulose on the shape memory behavior of polyvinyl alcohol nanocomposite hydrogel |
| Paper ID : 1095-UFGNSM-FULL (R2) |
| Authors: |
|
PEGAH PIRAHMADI *1, Mehrdad Kokabi2 1Tehran, Jalal AleAhmad, Nasr, tarbiat modares university 2Polymer Engineering Department, Faculty of Chemical Engineering, Tarbiat Modares University, P.O. Box: 14115-114, Tehran, Islamic Republic of Iran |
| Abstract: |
| Most research on shape memory polymers has been confined to neat polymers in their dry state, while, some hydrogel networks are known for their shape memory properties. Hydrogels have low glass transition temperatures which are below 100°C depend on the content of water. But they are usually weak and brittle, and not suitable for structural applications due to their low mechanical strengths because of these materials have large amount of water (>50%), so they could not remember original shape perfectly. Bacterial cellulose nanofibers with perfect properties such as high water holding capacity, high crystallinity, high tensile strength and good biocompatibility can dismiss all the drawbacks. In the present study, polyvinyl alcohol/bacterial cellulose nanocomposite hydrogel prepared by repetitive freezing-thawing method. The bacterial cellulose was used as reinforcement to improve the mechanical properties and stimuli response. Differential scanning calorimetry was employed to obtain the glass transition temperature. Nanocomposite morphology was characterized by field-emission scanning electron microscopy and mechanical properties were investigated by standard tensile test. Finally, the effect of bacterial cellulose nano-whiskers on shape memory behavior of polyvinyl alcohol/bacterial cellulose nanocomposite hydrogel was investigated. It is found that switching temperature of this system is the glass transition temperature of the nano domains formed within the system. The results also show increase of shape recovery, and shape recovery speed due to presence of bacterial cellulose. |
| Keywords: |
| PVA hydrogel; Bacterial cellulose nanofibers; Shape memory; |
| Status : Paper Accepted (Poster Presentation) |
