Hybrid Block Copolymer Synthesis by Merging Photoiniferter and Organocatalytic Ring‐Opening Polymerizations

Abstract

Access to block copolymers from monomers that do not polymerize via a common mechanism requires initiation from a multifunctional species that allows orthogonal polymerization chemistries. We disclose a strategy to provide well‐defined polyacrylamido‐b‐polyether block copolymers by a one‐pot combination of photoiniferter polymerization and organocatalytic ring‐opening polymerization (ROP) using a hydroxy‐functionalized trithiocarbonate photoiniferter as the dual initiator at ambient temperature. Our results reveal good compatibility between the two polymerization systems and highlight that they can be performed in arbitrary order or simultaneously with good retention of the thiocarbonylthio functionality. We also demonstrate selective temporal control over the photoiniferter polymerization during concurrent ROP. We harnessed the efficiency of combining these polymerization systems to provide tailor‐made block copolymers from chemically distinct monomers.

Hybrid Photoiniferter and Ring‐Opening Polymerization Yields One‐Pot Anisotropic Nanorods

“…4‐Hydroxybutyl 2‐((dodecylthiocarbonothioyl)thio)‐2‐methylpropanoate was synthesized according to previous literature procedures. [ 27 ] l ‐Lactide (TCI) was recrystallized three times from toluene. Anhydrous toluene (99.8%), DBU, and (−)‐sparteine were obtained from Sigma‐Aldrich and stored under 4 Å molecular sieves.…”

“…[24,25] As far as we know, this is the sole example of PDMA-b-PLLA synthesis in a two-pot, two-step manner. [24][25][26] Recently, Xia et al [27] showed that photoiniferter polymerization and organocatalytic ROP could be performed stepwise or synchronously using a hydroxy-functionalized trithiocarbonate (TTC) dual-initiator for the one-pot production of polyacrylamido-b-polyether BCPs. Photoiniferters enable the polymerization of vinyl monomers with predictable molecular weights, low dispersity (Ð), and high end-group fidelity with the advantage of being performed at ambient conditions.…”

“…[ 33,34 ] However, these ROPs are typically performed in solvents at monomer concentrations of around 1 m , [ 25,35 ] whereas the photoiniferter polymerization of polyacrylamides is carried out at higher monomer concentrations. [ 27 ]…”

A Photoinduced Dual‐Wavelength Approach for 3D Printing and Self‐Healing of Thermosetting Materials

“…As expected, samples were not healed after 16 h in the absence of UV light, as the TTC units of DBTTC in the network cannot be activated without light irradiation at room temperature. Under white light irradiation for 24 h, 35±2% tensile strength recovery was observed (Supporting Information, Characterization, Table S1), which was attributed to the low homolysis rate of C−S bonds under white light [9j] . To demonstrate the importance of TTC in the polymer network, control samples were printed in the absence of DBTTC and subsequently used in self‐healing tests (Supporting Information, Characterization).…”

Unlocking the Photoredox and Photoacid Dual Catalytic Activity of BINOLs for the Development of Organocatalytic Orthogonal Polymerization of ATRP and ROP with Light Regulation

“…Living polymerization provides powerful tools for polymer synthesis, featuring its precise controls over the polymer sequence, architecture, functionality, etc. − Recently, the integration of light regulation into living polymerization methods has shown many advantages, featuring further improved precision and additional controls over chain growth in spatial and temporal dimensions. − This advancement has also led to the development of orthogonal photocontrolled polymerizations by integrating a light-regulated polymerization with another polymerization method, which could thus enable the synthesis of block copolymers comprising different block compositions in a one-pot process. In this regard, the orthogonality of living radical polymerization (LRP) and ring-opening polymerization (ROP) has attracted considerable research interest, which could allow access to various block copolymers (e.g., polyacrylate- b -polyester) with diverse functions and applications in biomedical engineering fields, drug delivery, degradable polymers, antifouling agents, etc. − Typically, to synthesize these block copolymers, a two- or multicatalyst system was used, as the radical polymerization of vinyl monomers and the ring-opening polymerization of lactones proceed via inherently different mechanisms (Figure A). − For example, Goto and Kaji reported an effective orthogonality of photocontrolled iodide-mediated LRP with ROP by employing a sulfonium-type photoinitiating acid precatalyst .…”