Diisocyanate‐based chain extension via Mg(<scp>II</scp>) catalyzed amide formation to high‐molecular‐weight poly(lactic acid)

Abstract A simple chain‐extension reaction using diisocyanate as a chain extender was adopted to increase the molecular weight of low‐molecular‐weight (LMW) poly(lactic acid) (PLA) synthesized via direct polycondensation and recover commercial PLA after service life. The slow between carboxylic acid terminus successfully accelerated Mg(II) catalyst, affording linear chain‐extended (cePLA) connected through amide bonds. To number bonds, which exhibit higher thermal stability than urethane bonds that are formed in more common reactions isocyanates hydroxy PLA, telechelic LMW‐PLA having groups at both termini prepared. Subsequent this with presence catalyst afforded cePLA high (M w &gt; 180 × 10 3 g/mol) enhanced against degradation, while showing identical mechanical properties biodegradability PLA.