Molecular and kinetic design for the expanded control of molecular weights in the ring-opening metathesis polymerization of norbornene-substituted polyhedral oligomeric silsesquioxanes
| Autor: | Myung-Jin Kim, Jae-Suk Lee, Mallela Yadagiri Lakshmi Narasimha Kishore, Yong-Guen Yu, Ho-Bin Seo, Chang-Geun Chae |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Polymers and Plastics Organic Chemistry Bioengineering 02 engineering and technology ROMP 010402 general chemistry 021001 nanoscience & nanotechnology Metathesis Macromonomer 01 natural sciences Biochemistry Silsesquioxane 0104 chemical sciences chemistry.chemical_compound chemistry Polymerization Polymer chemistry Copolymer Ring-opening metathesis polymerisation 0210 nano-technology Norbornene |
| Zdroj: | Polymer Chemistry. 9:5179-5189 |
| ISSN: | 1759-9962 1759-9954 |
| DOI: | 10.1039/c8py00870a |
| Popis: | Cube-like polyhedral oligomeric silsesquioxane (POSS) is a promising candidate for isotropically bulky pendants to expand the dimensional limit of polymer main chains. This paper presents molecular and kinetic insights into the controlled synthesis of rod-like POSS-containing polynorbornenes. Ring-opening metathesis polymerization (ROMP) was performed on three norbornene-substituted POSS monomers with different spacers. For monomers possessing non- and amide functionalities at the spacers, ROMP at the maximum concentration ([M]0 = 0.4 M) led to 100% conversion, predictable molecular weights (Mn ≤ 1236 kDa) and low dispersities (Đ ≤ 1.20) in homopolymers. Scaling analysis for POSS-containing polynorbornenes revealed an unusual finding, namely, that the periodic clustering of POSS pendants favored by long flexible spacers (16-atom chains) enhanced the rigidity of polynorbornene main chains, leading to their rod-like conformation. Kinetically optimized ROMP allowed the subsequent addition of a macromonomer to create POSS-bottlebrush copolymers (POSSBBCPs). These POSSBBCPs self-assembled into thin films to form ordered nanostructures with diverse morphologies and periodicities greater than 100 nm. |
| Databáze: | OpenAIRE |
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