Abstract
Upon extending a hydrophobic polymer chain from the end of a preceding hydrophilic chain in aqueous solutions, the resultant block copolymers may eventually undergo self-assembly. Further chain propagation continues in the newly formed hydrophobic polymer rich domain. This process is often referred to as polymerization-induced self-assembly (PISA). Its kinetics are determined by the polymerization and the micelle formation/growth, which may influence each other, possibly leading to a highly complex process of structural development. In this study, we examined PISA in aqueous solution on the reversible addition fragmentation chain transfer (RAFT) dispersion polymerization of poly(N-acryloylmorpholine)-b-poly(N-acryloylthiomorpholine). Using in situ small-angle X-ray scattering (SAXS) and nuclear magnetic resonance spectroscopy (NMR), the polymerization and micelle formation were observed. In the analysis, because the time scale of the micelle formation/growth is much shorter than that of the polymerization, the polymerization and micelle fomarion/growth can be decoupled. Thus, these were separately analyzed in depth, and a combination of the kinetics of RAFT polymerization and the simple scaling theory of the micellar structures can quantitatively describe the overall micellar structural development during PISA. This study provides an unprecedented insight into the processes underlying PISA and deepens our quantitative understanding of it.
| Original language | English |
|---|---|
| Pages (from-to) | 1514-1524 |
| Number of pages | 11 |
| Journal | Polymer Chemistry |
| Volume | 11 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 28 Feb 2020 |
| Externally published | Yes |
Bibliographical note
Funding Information:The SAXS experiments were performed at SPring-8 under the approval of JASRI (proposal numbers: 2018A1454 and 2018B1396). This work was financially supported by JST CREST (JPMJCR1521). J. B. and F. S. further thank the DFG for generous funding in the Emmy-Noether-Program (BR 4905/3-1) and the SFB 1278 Polytarget (project A05), respectively.
Funding
The SAXS experiments were performed at SPring-8 under the approval of JASRI (proposal numbers: 2018A1454 and 2018B1396). This work was financially supported by JST CREST (JPMJCR1521). J. B. and F. S. further thank the DFG for generous funding in the Emmy-Noether-Program (BR 4905/3-1) and the SFB 1278 Polytarget (project A05), respectively.