Palindromic sequence-induced specific and genetic functions widely exist in biological systems. Nevertheless, the study of synthetic palindromic sequence-defined polymers has received rare attention due to the challenge of efficient synthesis....

A series of quaternary copolymerized thermoplastic polyimides (PI) films with good thermal resistance has been synthesized via two-step method from bicomponent isomeric dianhydrides, 2,3′,3,4′-biphenyltetracarboxylic dianhydride (α-BPDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), and bicomponent flexible diamines, 4,4′-oxydianiline (ODA) and 1,3-bis(4′-aminophenoxy)benzene (TPE-R). By adjusting the molar ratio of dianhydrides to diamines, its effects on the thermal stability, thermoplasticity and solubility of PI films were investigated in detail. The results showed that these quaternary copolymerized PI films were in possession of both thermoplasticity and excellent thermal stability. It is derived from the synergetic effect of isomeric dianhydrides and flexible diamines. It has also been found that there is one critical molar ratio between dianhydrides and diamines, that is, α-BPDA:s-BPDA:ODA:

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The on-demand building copolymer structures, from sequence to architecture, is crucial in understanding the relation between polymer structure and property, meanwhile motivating the innovation of polymer hierarchy. However, the challenge is conspicuous for complicated polymer structures from inherently intricate polymerization. In this work, copolymers with tailored grafting density and distributions were achieved using successive latent monomer and grafting-from strategies. The hydroxyl group functionalized furan/maleimide adduct (FMOH) was selected as the latent monomer for RAFT polymerization of an array of copolymers with tailored localization of hydroxyl group along the main chain. The hydroxyl group further initiated the ring opening polymerization (ROP) of L-lactide or ε-caprolactone, resulting in a library of multicomponent copolymers via grafting-from strategy. The initiating efficiency reached to ~100% with variable molecular weight (21 300-58 600 Da) and narrow distributions (Ð M < 1.25), indicating that such graft copolymers possessed controlled density and distribution of side chains as its linear template. The investigation on thermal properties of the well-defined graft copolymers implied that the precise tailoring over copolymer structures at the molecule level could lead to tunable chemical/physical properties. This work bridged polymer from sequence to architecture, unveiled a new method in creating graft copolymers with programmable structures and provided the insight into the structure/property relationship.