Buthaina A .I; Nahida J.H; afr Hussain koaer
Abstract
The study is aimed at preparing poly vinyl alcohol (PVA) hydrogel by physical techniques using freeze/thaw method and by chemical method via the addition of cross linking agents, such ...
Read More ...
The study is aimed at preparing poly vinyl alcohol (PVA) hydrogel by physical techniques using freeze/thaw method and by chemical method via the addition of cross linking agents, such as Glutaraldehyde (GLT) in different percentages of (1%) and (3%) and boric acide (BA) with percentage of (o.5%) . we prepared of poly vinyl alcohol and Chitosamine chloride (CsmCl) with different weight ratios . These specimens are prepared in the shape of films . Studies are made on swelling behavior for all prepared samples in different media of PH (neutral , acidic and alkaline) , using Fourier Transform Infra Red (FTIR) in order to investigate the linking between (PVA) and cross linking agents and the blends . From the test result , it is found that swelling percentage depends on cross linking degree , whether it is physical or chemical ; all sample possess high swelling percentage during the first 5 hours then settle at discrete percentage , which are attributed to disentanglement of chains that are not involved in cross linking . The freeze/thaw process leads to physical cross linking of polymer chains. Results have proved that samples containing (1%GLT) and (0.5% BA) undergo increase in their water absorption after freezing and thawing , while samples containing (3%GLT) have undergone decrease in percentage . As to swelling ration in alkaline medium increase , while the (PVA) sample retained their swelling percentage in the acidic media , as in distilled water for samples containing (GLT) . As for swelling behavior of blends , the swelling percentage is found to increase with increase of (PVA) percentage , which may be attributed to increase water absorbing (OH) in the blends . The FTIR spectra for all samples before and after blending and treatment are found to appear and disappear besides band shift at different location; this is attributed to changes in conformation. The spectral intensity decreases with increasing (CsmCl) percentage explained in view of when two polymers or more are blended , changes occur in the characteristic spectra as a result of reflection in the blend that are prepared by physical mixing and chemical reaction