Abstract
To develop a new elastomeric impression material “Themoplastic-elastomer impression material” which indicates reversible thermal change, polycaprolactone-poly (dimethylsiloxane) block copolymers were designed and synthesized as a base polymer of the material. A coupling method was adopted to link mono-and/or difunctional polycaprolactone and poly (dimethylsiloxane) α, ω-diol, using α, ω-bis (dimethylamino) octamethyltetrasiloxane as a coupling agent. Block copolymers were obtained which had rubber elasticity at room temperature and reproducibility above the temperature of 55℃, at which the caprolactone segments melted. The dynamic rigidity of the blockcopolymers ranged from 0.2MPa to 0.5MPa at 25℃ (20〜70Hz). Melting viscosities varied with the molecular weight. They were less than 900Pa・s for high molecular weight compounds and less than 200pa・s for low molecular weight compounds, respectively, at 70℃ and 2sec-1.
