ABSTRACT PEG at compositions of 10, 15 and
20 g were added into the initial formulation of hydrogel L, which was composed
of 6 g low molecular weight chitosan (LMC) and 14 g poly (vinyl pyrrolidone) in
100 g of 2% lactic acid. The mixtures were moulded and exposed to γ radiation
at 7 kGy. The hydrogels obtained were characterized in term of gel fraction,
swelling property, syneresis effect, FTIR, XRD and cross section morphology.
The results indicated PEG reduces almost 27% crosslinking density of the LMC-PVP
hydrogel yet increased hydrogel’s water holding capacity from 450% and 480% to
750% and 650% in phosphate buffer solution (PBS) at pH5.5 and pH7.0,
respectively. Also PEG enhanced the ability of LMC-PVP hydrogel to retain its
moisture from dehydration at body temperature. The morphological study showed
PEG developed thick pores wall and reduced the pores size of the hydrogels’
network.
Keywords: Covalent-crosslink; plasticizer;
porosity; swelling-equilibrium; syneresis
