Synthesis of high molecular weight polylactic acid from aqueous lactic acid co-catalyzed by tin(II)chloride dihydrate and succinic anhydride.

Polylactic acid was synthesized from commercial available cheap aqueous lactic acid (85%–90% w/w) using succinic anhydride and SnCl₂·2H₂O as catalyst in the absence of organic solvents. As a result, polylactic acid with a molecular weight of 60000 was prepared in 10 h. The new procedure is much simple, cheap and outstanding in that the start material is aqueous lactic acid; the catalytic system is environmentally benign. [ABSTRACT FROM AUTHOR]