Synthesis and properties of biomass eugenol-functionalized isotactic Poly(1-butene)s

Functional isotactic poly(1-butene) (iPB) bearing natural antioxidant has been successfully synthesized via the MgCl2-supported TiCl4 Ziegler-Natta catalyst-mediated copolymerization of 1-butene with a renewable eugenol (EG) comonomer. The incorporated EG contents could be conveniently tailored by changing the comonomer loadings and reaction parameters such as temperature, molar ratio of co-catalyst/main catalyst (Ti), and external electron donor loading, up to 0.62 mol% EG units incorporated into iPB chain. Interestingly, the introduction of EG into the 1-butene polymerization are beneficial for improving the molecular weight of resultant copolymers. EG-functionalized iPB demonstrate a higher thermal-oxidative stability with respect to the pristine PB, nearly being proportional to the EG content, whose oxidation induction time (OIT) of iPB containing 0.62 mol% EG units is prolonged by 25 fold than that of iPB without EG units. Nevertheless, the EG counits in the iPB backbone limit the crystallization rate and suppress the Form II-Form I crystal transformation.