Synthesis and Crystallization‐Driven Self‐Assembly of Triblock Copolymers Based on Narrowly Distributed Poly( <i>p</i> ‐diethynylbenzene)

Poly(p-diethynylbenzene)s (PDBs) containing consecutive diacetylene units along their main chains exhibit distinctive optoelectronic properties. However, conventional oxidative homocoupling strategies fail to effectively control the molecular weight and dispersity of PDBs, which critically compromises polymer purity and material performance, thereby severely limiting their practical applications. In this study, we employed a confined polymerization method to restrict the formation of PDBs within the pores of a nanoreactor. This approach allows for better control over the step-growth polymerization process, as well as the molecular weight and its distribution of the resulting polymer. The narrowly distributed PDBs were subsequently functionalized into crystalline conjugated segments via azide-alkyne cycloaddition with polyethylene glycol monomethyl ether to construct triblock copolymers. We systematically investigated the crystallization-driven self-assembly behavior of these copolymers in solution, with particular emphasis on the morphological evolution of the cylindrical micelles through modulation of flexible chain lengths and solvent quality.