Abstract: There is provided a method of preparing a thermoplastic starch and synthetic polymer blend, said method comprising the steps of: (a) providing a starch suspension comprising starch, water and a plasticizer, preferably glycerol; (b) obtaining a thermoplastic starch from the starch suspension by causing gelatinization and plasticization of said starch suspension by exerting heat and pressure on said starch suspension in a first extrusion unit; (c) evaporating and venting off residual water from said thermoplastic starch to obtain a substantially moisture-free thermoplastic starch; (d) obtaining a melt of a synthetic polymer or polymer blend in a second extrusion unit; and (e) combining the melt obtained from step (d) with the substantially moisture-free thermoplastic starch. Also provided are compositions of matter comprising immiscible blends of thermoplastic starches, polymers, and compatibilizers.
Type:
Grant
Filed:
December 18, 2002
Date of Patent:
January 18, 2005
Assignee:
Polyvalor, Societe en Commandite
Inventors:
Basil D. Favis, Francisco Rodriguez, Bruce A. Ramsay
Abstract: There is provided a method of preparing a thermoplastic starch and synthetic polymer blend, said method comprising the steps of:
(a) providing a starch suspension comprising starch, water and a plasticizer, preferably glycerol; (b) obtaining a thermoplastic starch from the starch suspension by causing gelatinization and plasticization of said starch suspension by exerting heat and pressure on said starch suspension in a first extrusion unit; (c) evaporating and venting off residual water from said thermoplastic starch to obtain a substantially moisture-free thermoplastic starch; (d) obtaining a melt of a synthetic polymer or polymer blend in a second extrusion unit; and (e) combining the melt obtained from step (d) with the substantially moisture-free thermoplastic starch. Also provided are compositions of matter comprising immiscible blends of thermoplastic starches, polymers, and compatibilizers.
Type:
Grant
Filed:
December 27, 1999
Date of Patent:
August 12, 2003
Assignee:
Polyvalor Societe en Commandite
Inventors:
Basil D. Favis, Francisco Rodriguez, Bruce A. Ramsay