Properties of copolymers of aspartic acid and aliphatic dicarboxylic acids prepared by reactive extrusion

✍ Scribed by Randal L. Shogren; J. L. Willett; David Westmoreland; Sergio O. Gonzalez; Kenneth M. Doll; Graham Swift

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 100 KB
• Volume: 110
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.28944

✦ Synopsis

Abstract

Aspartic acid is prepared chemically or by the fermentation of carbohydrates. Currently, low molecular weight polyaspartic acids are prepared commercially by heating aspartic acid at high temperatures (>220°C) for several hours in the solid state. In an effort to develop a more rapid, continuous, melt polymerization scheme, aspartic acid was copolymerized with adipic, azelaic, sebacic, and dodecanedioic acids using a vented twin‐screw extruder. Copolymers having ratios of aspartic/diacid ≤16 and M~w~ up to 9100 were prepared at temperatures of 240–260°C and residence times of only about 5 min. M~w~ generally increased with aspartic/diacid ratio but melt viscosities became very high and processing became difficult at ratios >16. Most of the copolymers exhibited inhibition of calcium carbonate precipitation at concentrations similar to that of pure polyaspartic acid and thus may find application as antiscalants. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008