Constructing
stable co-continuous morphology of commercial immiscible
polymer blends remains an ongoing challenge in terms of complex presynthetic
routes, multiple parameter dependency, and intrinsic instability of
phase morphology. Herein, we demonstrate a full biodegradable polymer
blend, poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate), where hitherto inaccessible co-continuous with asymmetric
compositions (70/30) can be obtained with the assistance of interfacial
stereocomplex crystallites (i-SCs) through reactive blending. By taking
full advantages of this unprecedented compatibilizer, nanostructured
co-continuous blends with synergistically enhanced comprehensive performance
are achieved. First, due to the “rigid” i-SC, co-continuous
morphology is induced through a simple melt blending procedure; second,
considerable augmentation of the crystallization rate of the PLA matrix
is accomplished on account of the in situ formed
nucleation agent (i.e., i-SC); third, a super toughened
material with simultaneously enhanced tensile strength, ductility,
and impact strength can be acquired, resulting from the i-SC-induced
co-continuous morphology; and fourth, i-SC can function as a “rigid”
supporting layer between phases even above 200 °C, resulting
in significantly enhanced morphology stability in melt. The versatile,
facile, and practical strategy offers an industrially relevant technique
to fabricate super-robust and fully biobased polymer materials.