Preparation And Properties Of PVA Composite Hydrogels

Hydrogel is a kind of three-dimension polymer network which contains a lot of water. Among numerous hydrogels, poly (vinyl alcohol) (PVA) hydrogel, for its biocompatibility and chemical stability, has wide application potential in the fields,such as biology and medicine. Because of the weak mechanical performance of the hydrogels, its application in the biomedical fields, such as the subtituted cartilage tissue, has been limited. In order to overcome the weak mechanical property of the hydrogels, xanthan gum (XG), sodium carboxymethylcellulose (CMC), and graphite oxide were introduced into the PVA hydrogel and we prepared four kinds of hydrogels, PVA/XG?PVA/XG/GO?PVA/CMC and PVA/CMC/GO hydrogels.The results of the Fourier Transform Infrared Spectroscopy (FTIR) and the X ray diffraction analysis proved that the GO was successfully made. Besides, the structure of the prepared hydrogels were analysed by FTIR which might prove the ether bonds and other corresponding bonds were generated and the hydrogels were successfully prepared. The crystallinity of hydrogels dried were measured by XRD and the value of crystallinity was declined after the XG, CMC and GO were introduced into the PVA hydrogel coMPared to the PVA hdyrogel; the modulus of the hydrogels was measured by the dynamic mechanical thermal analysis (DMA); the water-untake kinetics was analysed by the mass of water up-taked changing with time; the dehydration thermodynamics of the hydrogels was analysed with the measured results of the differential scanning calorimetry (DSC). The modulus of the hydrogels was improved greatly and the water-untake kinetics and the dehydration thermodynamics was also altered after the introduction of the XG, CMC and GO.(1) For the PVA/XG hydrogels, when the mass ratio of the PVA and XG is 50:1, the modulus of this hydrogel attained the maximum,0.035 MPa, compared with that of the PVA hydrogel,0.005 MPa, that is, the modulus of hydrogel improved 700%, the crystallinity of this hydrogel dried decreased to 17.3% from that of the PVA hydrogel,64.1%. Meanwhile, the equlibrium swelling ratio of this hydrogel was increasing to 1206% from that of the PVA hydrogel,486%.(2) For the PVA/XG/GO hydrogels, when the mass ratio of the PVA, XG and GO is 50:1:0.1, the modulus of this hydrogel reached maximum,0.045 MPa, ascending to 900%, and the crystallinity of it was 24.8%, and the equlibrium swelling ratio of it approached to 900%.(3) For the PVA/CMC hydrogels, when the mass ratio of the PVA and CMC is 5:1, the modulus of this hydrogel reached maximum,0.1 MPa, increasing to 2000%, and the crystallinity of it was 13.4%, and the equlibrium swelling ratio of it approached to 2202%.(4) For the PVA/CMC/GO hydrogels, when the mass ratio of the PVA, CMC and GO is 5:1:0.1, the modulus of this hydrogel reached maximum,0.14 MPa, ascending to 2800%, and the crystallinity of it was 29.3%, and the equlibrium swelling ratio of it approached to 1601%.