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 plasticised, 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 towards 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.
Claims18
A composition, comprising a starch and a polymer acting as coupling agent which is chosen from the group consisting of polyethylene modified by grafting maleic anhydride, and terpolymers containing units derived from maleic anhydride, 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 0.1 rad per s (0.1 s.sup.-1), being greater than 1.6.
A process for preparing a composition, comprising starch and a polymer acting as a coupling agent which is chosen from the group consisting of polyethylene modified by grafting maleic anhydride, and terpolymers containing units derived from maleic anhydride, 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 0.1 rad per s (G'/G"), being greater than 1.6, said process comprising plasticising a mixture comprising the coupling agent and starch.
A composition, comprising a starch and a polymer acting as coupling agent, selected from the group consisting of polyethylene modified by grafting maleic anhydride, and terpolymers containing units derived from maleic anhydride, the ratio of the dynamic modulus of elasticity G' of said composition to the dissipative modulus G" of said composition being greater than 1.6.
A process for preparing a composition comprising starch and a polymer acting as a coupling agent, selected from the group consisting of ethylene modified by grafting maleic anhydride, and terpolymers containing units derived from maleic anhydride, the ratio of a dynamic modulus of elasticity G' of said composition to the dissipative modulus G" of said composition being greater than 1.6, said process comprising plasticising a mixture comprising the starch and coupling agent.
Dependencies are inferred from the claim text.