In-situ reactive compatiblization modified poly(l-lactic acid) and poly (butylene adipate-co-terephthalate) blends with improved toughening and thermal characteristics

Triglycidyl isocyanurate (TGIC) with multifunctional epoxy is used for reactive compatibilization of Poly (l-lactic acid) (PLLA)/Poly (butylene adipate-co-terephthalate) (PBAT) blends. Interfacial tension, FTIR and SEM results show that TGIC has greater affinity and stronger reactivity with PBAT. The mixing sequence of PLLA/PBAT/TGIC blends has a significant impact on the compatibility. The TGIC and PBAT are reactive blended first, followed by the PLLA, which is most advantageous to produce a substantial amounts of branched copolymers PLLA-g-PBAT at the interface for the (PBAT/4%T) /PLLA blend. The considerable improvement of interfacial compatibility and the thickening of interfacial layer promote the stress transfer from the matrix to the dispersed PBAT phase. In comparison to PLLA/PBAT blend, the breaking elongation of (PBAT/4%T)/PLLA blend is raised by 25.6 times up to 164.2 % and the tensile strength is enhanced up to 32.1 MPa. The present work offers valuable perspectives on how to encourage the efficient application of reactive compatibilizers with epoxy groups in polyester blends.