Thermal, Mechanical and Rheological Properties of Poly(lactic acid) Chain Extended with Polyaryl Polymethylene Isocyanate

In this study, polyaryl polymethylene isocyanate (PAPI) was used as a chain extender for poly(lactic acid) (PLA) to produce a high molecular weight material with better rheological, thermal and mechanical properties. The reaction between PLA chains and PAPI was proved by FTIR during reactive blending. The results showed that the molecular weight and molecular weight distribution were increased with the addition of PAPI content due to the chain extension. Chain extension was also responsible for the increased modulus and complex viscosity. The glass transition temperature (T-g) and thermal stability increased by incorporating with PAPI. The results of mechanical properties showed that a considerably higher tensile strength and Young's modulus of the reactive blends compared with neat PLA.