Biodegradable polymers from renewable sources: rheological characterization of hemicellulose-based hydrogels.
Hemicellulose-based hydrogels were prepared by radical polymerization of 2-hydroxyethyl methacrylate or poly(ethylene glycol) dimethacrylate with oligomeric hydrosoluble hemicellulose modified with well-defined amounts of methacrylic functions. The polymerization reaction was carried out in water at 40 degrees C using a redox initiator system. The hydrogels were in general elastic, soft, and easily swellable in water. Their viscoelastic properties were determined by oscillatory shear measurements on 2 mm thick hydrogels under a slight compression to avoid slip, over the frequency range 10(-1) to 10(2). The rheological characterization indicated that the elastic response of the hydrogels was stronger than the viscous response, leading to the conclusion that the hydrogel systems displayed a predominantly solid-like behavior. The curves showed an increase in shear storage modulus with increasing cross-linking density. The nature of the synthetic comonomer in the hemicellulose-based hydrogels also influenced the shear storage modulus. Comparison of hemicellulose-based hydrogels with pure poly(2-hydroxyethyl methacrylate) hydrogels showed that their behaviors were rather similar, demonstrating that the synthetic procedure made it possible to prepare hemicellulose-based hydrogels with properties similar to those of pure poly(2-hydroxyethyl methacrylate) hydrogels.
Söderqvist Lindblad
Margaretha
M
KTH Fibre and Polymer Technology, Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden.
Albertsson
Ann-Christine
AC
Ranucci
Elisabetta
E
Laus
Michele
M
Giani
Elena
E
D001673:Biodegradation, Environmental; D003247:Conservation of Natural Resources; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D011092:Polyethylene Glycols; D011102:Polyhydroxyethyl Methacrylate; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011134:Polysaccharides; D012212:Rheology
D020100:Hydrogels; D011108:Polymers; D011134:Polysaccharides; D011102:Polyhydroxyethyl Methacrylate; D011092:Polyethylene Glycols; C007916:hemicellulose