1992 Volume 40 Issue 7 Pages 1897-1901
The influence of the addition of powder on the viscoelasticity of carboxycinylpolymer (CVP) hydrogel was studied by the oscillation method. The powder-filled hydrogels (PFHs) were prepared using Hiviswako 103 and 105 (CVP of rich side chains and poor side chains, respectively), and six powders [zinc oxide (ZnO), titanium dioxide (TiO2), magnesium stearate (StMg), talc, synthetic aluminum silicate (SiAl), and hydrated silicone dioxide (Cp)].The profiles of storage modulus (G') and loss modulus (G") of each PFH differed depending on powder and CVP. log G' and log G" changed little with TiO2, monotonously increased with talc, StMg and Cp, and showed fairly complex behaviors differing with polymer species with znO and SiAl. Plotting according to the kerner equation suggested that powder bridge structures were formed in the PFHs.The possible structures formed in the PFHs were presumed as follows on the basis of their viscoelasticity change and microscopic observation. With TiO2 : the original hydrogel network was not ruptured and powders were dispersed uniformly in the gel network. With talc, StMg and Cp : the original hydrogel networks and the powder bridge structures coexisted. With ZnO and SiAl : the original hydrogel networks were ruptured and powder bridge structures were constructed.
