Polymers find a widespread application in therapeutics and their use can play important structural and functional roles in different disease conditions. Bioartificial biodegradable materials, to be used as biomaterials and, in particular, as localised drug carriers, were prepared mixing chitosan (CHI) and poly(vinyl alcohol) (PVA), then manufactured as films, and finally cross-linked with glutaraldehyde (GTA), both in the absence and in the presence of the edible plasticizer sorbitol (SOR). The materials were characterised by Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction, scanning electron microscopy (SEM), and tensile test. The FTIR spectroscopy and the X-ray diffraction indicate that the presence of CHI lessens the crystallinity of PVA, and that the cross-linking with GTA does not modify the interactions between the two polymers, but only forms bridges between the different chains. Also the thermodynamic parameters for PVA, evaluated from the DSC measurements, confirm that the structure of PVA is less crystalline in the blends than in the pure state. The addition of SOR as a plasticizer to the CHI/PVA blends generally improves the characteristics of the films, making the cross-linked films less brittle, as confirmed by the SEM measurements and by the mechanical test. The TGA measurements confirm the presence of chemical interactions between the polymers, as indicated by the DSC measurements. On the whole, the physico-chemical properties of the blends show the strong interactions existing between the component materials.
Biodegradabile bioartificial materials made by chitosan and poly(vinyl alcohol). Part I: Physicochemical characterization
Cristallini C;Guerra G D;
2007
Abstract
Polymers find a widespread application in therapeutics and their use can play important structural and functional roles in different disease conditions. Bioartificial biodegradable materials, to be used as biomaterials and, in particular, as localised drug carriers, were prepared mixing chitosan (CHI) and poly(vinyl alcohol) (PVA), then manufactured as films, and finally cross-linked with glutaraldehyde (GTA), both in the absence and in the presence of the edible plasticizer sorbitol (SOR). The materials were characterised by Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction, scanning electron microscopy (SEM), and tensile test. The FTIR spectroscopy and the X-ray diffraction indicate that the presence of CHI lessens the crystallinity of PVA, and that the cross-linking with GTA does not modify the interactions between the two polymers, but only forms bridges between the different chains. Also the thermodynamic parameters for PVA, evaluated from the DSC measurements, confirm that the structure of PVA is less crystalline in the blends than in the pure state. The addition of SOR as a plasticizer to the CHI/PVA blends generally improves the characteristics of the films, making the cross-linked films less brittle, as confirmed by the SEM measurements and by the mechanical test. The TGA measurements confirm the presence of chemical interactions between the polymers, as indicated by the DSC measurements. On the whole, the physico-chemical properties of the blends show the strong interactions existing between the component materials.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
