Starch-based composition
AssigneeSolvay (Societe Anonyme)
InventorsClaude Dehennau, Thierry Depireux
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Abstract
The invention relates to an alloy composition possessing improved properties of mechanical resistance. The composition contains a starch, which is preferably plasticized, and a polymer which acts as coupling agent which is chosen from the group consisting of polyolefins modified by chemical functional groups which are active toward the hydroxyl functional groups of starch. Generally, the composition also contains a thermoplastic polymer. The invention also relates to the process for preparing this composition and the use of these compositions for the manufacture of films intended for the paper market and for packages made from biodegradable plastic.
Claims17
A composition comprising a starch and a coupling agent which is a polymer chosen from the group consisting of polyethylene modified by grafting maleic anhydride, and ethylene terpolymers containing units derived from maleic anhydride, the ratio of the dynamic modulus of elasticity G' to its dissipative modulus G" of said composition measured at 160.degree. C. and a frequency of 100 rad per second, being greater than 1.6.
A process for preparing a composition comprising starch and a coupling agent which is a polymer chosen from the group consisting of polyethylene modified by grafting maleic anhydride, and ethylene terpolymers containing units derived from maleic anhydride, said process comprising a step for plasticising a composition comprising said coupling agent and starch until the ratio of the dynamic modulus of elasticity G' of said composition to the dissipative modulus G" of said composition, measured at 160.degree. C. and at a frequency of 100 rad per s (G'/G"), is greater than 1.6, and recovering said plasticised composition.
Dependencies are inferred from the claim text.