Typical Formulation Ingredients
Ingredient
Parts by weight
Resin grade polylactic acid (NatureWorks)
Lactic acid based tackifying resin
Plasticizer (Sanitizer 160, ERA Polymers)
(Source: US Patent 5,753,724)
Typical Properties
T-Peel strength (gm) and failure mode on substrate:
• Starch-polycaprolactone
Kraft-to-Kraft 100 gm peel failure temperature
Kraft-to-Kraft 500 gm shear failure temperature
Resulting Properties
The initial application for biobased PLA in adhesives appears to be as a hot melt, possibly for food packaging applications. The commercial driver is their thermoplastic flow characteristics and their excellent biodegradability. Thus, PLA adhesives can be used to maintain the good biodegradability of natural fiber based packaging materials or of packaging made from other biodegradable polymers. A limiting factor for PLA is its brittleness. This, however, is being addressed by the use of tougheners and other additives in a PLA plastic blend.