Facile Synthesis of Well-Defined Gradient 4-Vinylbenzyl-piperidine/β-Myrcene Copolymer via Living and Controlled Anionic Copolymerization under mild conditions

To develop myrcene-based polymers with both functionalization characteristics and controllable structure, this paper employs 1-(vinylbenzyl) piperidine (VBMP) as a tertiary amine functional monomer and achieves the controlled copolymerization of VBMP with β -myrcene (MY) under mild conditions above room temperature in cyclohexane using living anionic polymerization. By leveraging the dual role of VBMP as both a comonomer and a polarity regulator, and optimizing the monomer feed ratio, poly(MY- co -VBMP) copolymers with controllable molecular weight and narrow molecular weight distribution (1.11 < PDI < 1.23) are successfully prepared. 1 H NMR and FTIR characterizations confirm that VBMP is uniformly inserted into the polymer backbone via in-situ copolymerization, achieving a quantitative functionalization. The reactivity ratios are determined using the Fineman-Ross and Kelen-Tüdős methods, yielding r MY = 4.62-4.80 and r VBMP = 0.43-0.54. Moreover, DSC analysis shows that with increasing VBMP content, the glass transition temperature ( T g ) of the copolymers gradually rises from −18 °C to 25 °C, accompanied by significantly enhanced chain segment regularity. In addition, the LAP chain-end active center coordination mechanism and the N-Li coordination synergy mechanism within the polymer chain are proposed to rationalize the experimental results. Overall, this polymerization system not only exploits the weak regulatory effect of the tertiary amine group of VBMP on anionic polymerization but also achieves quantitative functionalization of β -myrcene copolymers, providing an efficient route to functional materials possessing both elastic properties and reactive sites.