Polymerization-Induced Self-Assembly of Poly(Vinyl Chloride)-Based Block Copolymers: A New Frontier for Commodity Polymer Nanotechnology

In this work, the potential of the polymerization induced self-assembly (PISA) methodology is explored for the first time for the synthesis of innovative tailor-made poly(vinyl chloride) (PVC) nanoparticles with controlled morphology. Initially, various PVC macromolecular chain transfer agents (macroCTAs) were successfully synthesized by macromolecular design via the interchange of xanthate (MADIX) polymerization of vinyl chloride (VC) and characterized using 1 H nuclear magnetic resonance spectroscopy ( 1 H NMR) and size exclusion chromatography (SEC). Subsequently, the PVC macroCTAs were used to yield poly(vinyl chloride)- b- poly(styrene) (PVC- b -PS) block copolymers via PISA of styrene (Sty), which underwent spontaneous in situ self-assembly, in dimethyl sulfoxide (DMSO). To the best of our knowledge, this work is also the first reported PISA system using PS as the core-forming block and DMSO as the continuous phase. The synthesis of PVC n - b -PS x nanoparticles using PISA was investigated under a wide range of reaction conditions, including varying temperature, block copolymer composition, and solids content (from 10 to 40 wt%). It was found that successful PISA of Sty from PVC n -CTAs in DMSO required temperatures below 55 °C. In addition to the structural characterization of PVC macroCTAs and PVC- b -PS block copolymers obtained by 1 H NMR spectroscopy and size exclusion chromatography (SEC), the PVC n - b -PS x dispersions were analyzed by dynamic light scattering (DLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The characteristics of PVC n - b -PS x nanoparticles (formation, stability and morphology) obtained by this PISA are strongly dependent on PISA temperature, PVC-MEA macroCTA design and solids content. Variations in the solids content and molar mass of the PS block induced the formation of diverse morphologies, including spheres and worms. In summary, this work presents a proof-of-concept demonstration of PVC-based MADIX-PISA as a platform for preparing of PVC- b -PS nanoparticles with tunable morphologies, laying the groundwork for future studies targeting applications in coatings, films, lithography, and polymer nanocomposites.