Research On The Physical-chemistry Properties Of Poly (Vinyl Alcohol) Composite Hydrogels

Polyvinyl alcohol (PVA) hydrogel has been recommended as a promising substitutefor biomedical and tissue engineering due to its good lubrication performance, highelasticity, highly biocompatibility, chemical stability, easy molding, biodegradable, andexcellent compatibility with the body’s tissues. However, there are still some mechanicaland bioeffective problems hindered the applications of pure PVA hydrogels. IntegratingPVA hydrogel with other materials to form composite hydrogels is a recommendedsolution. For example, to integrate it with chitosan (CS) and graphene oxide (GO). Thisarticle include two sub-items as listed below.Firstly, the PVA/CS composite hydrogel was prepared by freeze-thaw physicalcrosslinking associated with chemical crosslinking using glutaraldehyde (GA). Therheological properties, fracture morphology (SEM), thermal dehydration kinetics, FT-IR,XRD and othe physical and chemical properties of the hydrogel were systematicallystudied, and the influence of glutaraldehyde concentration, the mass ratio of gel, reactiontemperature and reaction time on water content and crystallinity were also investigated.The result shows that, the PVA/CS composite hydrogels modified by glutaraldehydepresent a porous three-dimensional and compact network structure. the moisture content,crystallinity and dehydration activation energy of the hydrogel were reduced. However theaverage energy storage modulus of PVA/CS-GA composite gel is increased.Secondly, the PVA/CS/GO composite hydrogel was prepared by freeze-thaw physicalcrosslinking method. The rheological properties, fracture morphology (SEM), thermaldehydration kinetics, FT-IR, XRD and othe properties were studied. The effect of thegraphene oxide concentration, the composition, the reaction temperature and time on thewater content and crystallinity were studied. The result shows that, GO was well dispersedin polymer matrix, and the composite hydrogel presents a porous three-dimensionalnetwork structure. GO enhanced the thermal stability, and reduced the dehydrationactivation energy. The storage modulus G’ of PVA/CS/GO hydrogel was higher than that of PVA or PVA/CS hydrogel in some composition region. In addition, there are noremakable effect on the equilibrium water content, but it improves the interface interactionbetween PVA and GO, and promotes the crystallinity.