| 학회 | 한국고분자학회 |
| 학술대회 | 2003년 봄 (04/11 ~ 04/12, 연세대학교) |
| 권호 | 28권 1호, p.2 |
| 발표분야 | 초청특별강연 |
| 제목 | Design of Functional Polymers Based on Organic Synthesis －Novel Ring-Opening Polymerization and Its Function－ |
| 초록 | Recent remarkable progress on initiator and monomer design has developed a wide variety of living ring-opening polymerization systems. Several attempts have been made to achieve controlled cationic ring-opening polymerization of lactones and cyclic carbonates. In this article, we wish to report controlled ring-opening polymerization of ε -caprolactone and cyclic carbonate derivatives. 1. Living Ring-Opening Polymerization of Lactone and Cyclic Carbonate by Alcohol-Hydrogen Chloride ε -Caprolactone and a seven-membered cyclic carbonate, 1,3-dioxepan-2-one undergo living polymerization with combination use of an alcohol as an initiator and hydrogen chloride as an activator.1) The molecular weight of the polymers can be controlled by the amount of the alcohol in the range of 103-104 maintaining a low polydispersity index. The second feeding of the monomer after completion of the first polymerization is converted quantitatively to afford the corresponding polymer with a low polydispersity index. Block copolymers of ε -caprolactone and the cyclic carbonate are satisfactorily obtained by the initiator system.2) Boron trialkoxide3) and boron trichloride4) instead of an alcohol are also effective for the controlled polymerization. 2. Living Ring-Opening Polymerization of Cyclic Monothiocarbonate A cyclic monothiocarbonate, 5,5-dimethyl-1,3-dioxane-2-thione undergoes living ring-opening polymerization with conventional cationic initiators such as Et2O · BF3, Et3O · BF4, TfOMe, and TfOH.5) The key importance for living tendency is isomerization of the thiocarbonyl group into more stable carbonyl group, preventing side reactions such as back-biting and transesterification. 3. Living Ring-Opening Polymerization of Cyclic Dithiocarbonate Based on Neighboring Group Participation A five-membered cyclic dithiocarbonate substituted with benzoxymethyl group undergoes living cationic polymerization. The propagating species is a cation stabilized by the neighboring ester group.6) References T. Endo et al. 1) Macromolecules, 33, 3590 (2000). 2) Macromolecules, 33, 4316 (2000). 3) Macromolecules, 33, 3630 (2000). 4) Macromol. Rapid Commun., 21, 489 (2000). 5) Macromolecules, 33, 7229 (2000). 6) Macromolecules, 31, 9093 (1998). |
| 저자 | Takeshi ENDO |
| 소속 | Department of Polymer Science and Engineering |
| 키워드 | |
