Yukong Limited

Won-yung Cho

Yong-wook Kim

Yong-deuk Yoo

In the present invention, the lowering of physical properties is minimized by bonding matrix resin and starch chemically using a coupling agent in the presence of an organic acid catalyst, at the same time lowering of the production cost is achieved by simplyfing the process. In the prior arts, the problems associated with low physical properties caused by starch incorporation were approached only in terms of enhanced physical interacting strength between matrix resin and starch. The purposes of the present invention are to provide a biodegradable polyethylene composition chemically bonded with starch comprising 100 parts by weight of matrix resin, 5-400 parts by weight of biodegradable incorporating material, 0.01-10 parts by weight of coupling agent, 0.01-1.0 parts by weight of radical initiator, 0.01-5 parts by weight of Lewis acid catalyst, 0.01-10 parts by weight of autoxidizing agent and 0.01-10 parts by weight of plasticizer and to provide a process for preparing thereof. The biodegradability of the polyethylene composition prepared by the present invention was determined in addition with reclamation test and shown to be excellent at a content of more than 10 wt. % of starch.

Biodegradable polyethylene composition chemically bonded with starch and

The present invention relates to a biodegradable film prepared by chemical bonding of starch and polyethylene chains using polyethylene, which is polyolefin having the most widest general application, coupling agent such as maleic anhydride, methacrylic anhydride or maleimide which bonds with starch and polyethylene, and acid catalytic comonomer like acrylic acid and/or methacrylic acid and to a process for preparing thereof. The present invention was accomplished varying coupling agent such as maleic anhydride, methacrylic anhydride or maleimide at an amount of 0.01-10 weight %, acid catalytic comonomer such as acrylic acid and/or methacrylic acid at an amount of 0.01-10 weight % and radical initiator at an amount of 0.01 1.0 weight % based on the amount of polyethylene, and the reactive extrusion was appelied to lower the production cost by process simplification. There was no difference in tensile strength and tensile elongation of the prepared biodegradable films comprising up to 20 wt. % of starch in comparison with the base resin by Instron measurement. The facts that ester bond showing chemical bonding between starch and matrix resin was found on the infrared absorption spectrum and the phenomenons that the boundary between matrix resin and starch particle is unclear, and the starch particle is cross-sectionally cut are shown on the cross-section of films with scanning electron microscope approving chemical bonding between starch and matrix. The biodegradability was the most excellent with more than 10 wt. % of starch.

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Incheon, South Korea

Won-yung Cho