Rheological properties of amorphous and semicrystalline polylactic acid polymers

摘要: Abstract Corn starch fermentation provides an abundant supply of lactic acid. Polymerization acid into polylactic (PLA) produces a biodegradable thermoplastic polyester with excellent functional properties comparable to many petroleum-based plastics. PLA polymers are made useful items using thermal processes, such as injection molding and extrusion. Therefore, its rheological properties, especially the shear viscosity ( η ), have important effects on film blowing, paper coating, molding, sheet forming fiber spinning. In this study, viscosities two types resins (amorphous semicrystalline) at 150 170°C various rates (30, 50, 70, 90, 110, 130, rpm screw speeds) were measured tube rheometer extruder. The data was calculated from pressure profiles volume flow rate. Statistical analyses performed SAS. resin type, temperature rate melt determined. Under same processing conditions, semicrystalline had higher than amorphous PLA. As increased, decreased for both characterized pseudoplastic, non-Newtonian fluid. Power law equations adequately described behavior melts r 2 >0.99).