Abstract
Poly (ethyl methacrylates) of different molecular weights were synthesized by suspension polymerization. These polymer powders, and a liquid that contained butyl phthalyl butyl glycolate and ethyl alcohol were used. The storage modulus G′, dynamic viscosity η′ and loss tangent tanδ of a mixture of powder and liquid were determined over the frequency range of 0.05 to 70 Hz at different temperatures. By the application of the time-temperature superposition principle, the curves of G′, η′ and tanδ versus frequencies at different temperatures for each material were superimposed to a single master curve. The remarkable effects of molecular weight of polymer on the viscoelastic properties of the materials found at the low frequency region; the lower the molecular weight, the lower the storage modulus G′ and the higher the loss tangent tanδ. These results suggest that in the use of poly (ethyl methacrylate) as the powder of tissue conditioner, the polymer should be adjusted to a lower molecular weight so that the material flows and deforms according to the recovery of the deformation of tissue.
