Synthesis of Diels-Alder network polymers from bisfuranic terminated poly(l-lactide) and tris-maleimide

Synthesis, recyclability, and physical properties of poly(l-lactide) (PLLA)-based network polymers prepared by means of Diels-Alder (DA) reaction between bisfuranic terminated PLLA prepolymers (PLLAnF2-x; degree of polymerization, n = 35-59, substituent in the vicinity of furan, x = amide or ester) and a tris-maleimide cross-linker (M3) are described. Molecular weight of prepolymer and substituent in the vicinity of furan rings are strongly effective in equilibrium control of DA and retro-DA reactions between PLLAnF2-x and M3. Lower molecular weight of the prepolymer and amide-substitution in the vicinity of furans significantly enhance the reactivity between PLLAnF2-x and M3, resulting in more perfect network structure, completely suppressed crystallinity, and much better mechanical properties of the PLLA-based DA network polymers. The PLLA-based DA network polymer containing numerous thermoreversible covalent bonds is a promising material as a readily recyclable biobased polymeric material.