Js. Park et E. Ruckenstein, Viscoelastic properties of plasticized methylcellulose and chemically crosslinked methylcellulose, CARBOHY POL, 46(4), 2001, pp. 373-381
Films of methylcellulose (MC), poly(ethylene glycol)400 (PEG400) plasticize
d MC, and MC gels (MC crosslinked with glutaraldehyde (GA)) were prepared b
y casting from aqueous solutions. The swelling test has shown that the MC g
els were insoluble in water and that their crosslinking density increased w
ith increasing GA and HCl concentrations. The effect of the addition of PEG
400 or GA to MC was investigated through dynamic mechanical analysis (DMA).
The DMA analysis of PEG400/MC blends has shown that PEG400 was compatible
with MC and was an effective plasticizer since the curves of tan delta agai
nst temperature exhibited single peaks (corresponding to a single glass tra
nsition temperature), which were displaced to lower values with increasing
PEG400 content. The thermogravimetric analysis (TGA) indicated that the the
rmal stability of MC was not affected by the chemical crosslinking. The ten
sile strength was slightly increased through crosslinking while the elongat
ion was slightly decreased. The presence of moisture in MC hydrogels decrea
sed the tensile strength and enhanced the elongation while the addition of
PEG400 decreased the tensile strength but sharply increased the elongation.
(C) 2001 Elsevier Science Ltd. All rights reserved.