| abstract |
According to the method of the present invention, a star-branched polymer is obtained by polymerizing lactide or lactic acid using an oil whose main component is triacylglycerol having at least three hydroxyl groups or epoxy groups in the molecule as an initiator. A polyester polyol can be obtained. Since this polyester polyol has low crystallinity and low melting point, it has good workability when used in various applications, and since it is derived from renewable resources, it is effective in protecting the global environment and measures against depletion of fossil resources. From the point of view, it is very good. |