Korea Advanced Institute of Science and Technology

Cheil Synthetics Inc.

Seong I Woo

Il Doo Kim

Dae W Ihm

Chang S Lee

Myung S Lee

Hae S Jun

Jung: Sung G

There is disclosed a biodegradable copolyester having a combination structure consisting of one or more repeating unit of alkyleneterephthalate and one or more repeating unit of hydroxyalkanoate, represented by the following general formula I: ##STR1## wherein n is an integer not more than 10, R is --CH.sub.3 or --C.sub.2 H.sub.5,

Biodegradable copolyester and method for preparing the same

A highly active Ziegler-Natta catalyst for polymerizing HDPE and LLDPE at low temperature and pressure may be prepared by reacting a magnesium compound and a halogen compound with an electron donor compound to dissolve, reacting the resulting solution with a titanium compound to obtain the homogeneous solution and then adding a small quantity of surfactant to the homogeneous solution. Ethylene polymers and copolymers were prepared by activating the resulting catalyst to obtain the granular polymer having density of from 0.92 to 0.98 g/cm.sup.3 and in which the particle size distribution was narrow.

Highly active ziegler-natta catalyst for polymerizing HDPE and LLDPE and

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Seoul, South Korea

Seong I Woo