| Project/Area Number |
11450356
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
高分子合成
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
SAWAMOTO Mitsuo Kyoto Univ, Engineering, Professor, 工学研究科, 教授 (90150325)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KAMIGAITO Masami Kyoto Univ., Eng.Assoc. Professor, 工学研究科, 助教授 (00273475)
|
|---|
| Project Period (FY) |
1999 – 2000
|
| Project Status |
Completed (Fiscal Year 2000)
|
| Budget Amount *help |
¥15,500,000 (Direct Cost: ¥15,500,000)
Fiscal Year 2000: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1999: ¥12,800,000 (Direct Cost: ¥12,800,000)
|
|---|
| Keywords | Cationic Polymerization / Lewis Acid / Polymerization in Water / Emilsion Polymerization / Stereospecific Polymerization / Rare Earth Metal Salt / Alkoxystyrene Monomers / Vinyl Ethers / アルコキスチレン |
|---|
| Research Abstract |
This research is to develop "cationic polymerization in water" and "stereospecific cationic polymerization", both of which have been considered very difficult in cationic polymerization of vinyl monomers. Both objectives have been achieved by designing Lewis acids as catalysts that control the growing carbocations. The achievements of this 2-year research is summarized as follows :
(A) Cationic Polymerization in Water
In general, cationic polymerization is impossible to proceed in water, because the growing carbocation and catalysts (Lewis acids) are readily deactivated. In this study, rare-earth metal trifluoromethanesulfonates (triflates) and related compounds are found to be eater-tolerant and can be used in cationic polymerization. The following have been achieved :
(a) Cationic Polymerization of p-Alkoxystyrenes in Water
1) Suspension polymerizations p-methoxystyrene and other monomers with rare-earth metal triflates and similar copper or zinc derivatives ;
2) Emulsion polymerizations with similar catalysts and amphiphilic compounds ;
3) Precision control of polymer molecular weight in water.
(b) Direct Living Cationic Polymerization of p-Hydroxystyrene
1) Direct polymerization of "unprotected" p-hydroxystyrene with boron trifluoride/alcohol initiating systems in aqueous acetonitrile solvent ;
2) Precision synthesis of block and random copolymers of the monomer.
(B) Stereospecific Cationic Polymerization
Stereoregulation is another difficult subject in cationic polymerization. This study is directed its design of Lewis acids to this area, and achieved the following :
(a) Highly isospecific polymerizations of isobutyl and isopropyl vinyl ethers with bisphenoxy titanium dichlorides in nonpolar media at -78℃ ; isotacticity > 90%.
(b) Isospecific cationic polymerizations of alkyl vinyl ethers with phosphinic acids with long alkyl substituents.
|
