- 作者: 楊美惠 ; 楊正乾 ; 周全
- 作者服務機構: 台灣大學化學系
- 中文摘要: Methods based on anionic ring-opening polymerization, using n-butyl lithium as an initiator, were developed to prepare monodispersed (Mw/Mn<1.2) poly [ methyl(3,3,3- trifluoropropyl)siloxane ] (PMFPS) from methyl(3,3,3- trifluoropropyl) cyclotrisiloxane (F/sub 3/) in high yield. The resulting polymers have the molecular weights ranged from 4k to 190k (k=1000). Each polymer was characterized by GPC and DSC. The absolute molecular weight (Mw) of each monodispersed PMFPS was determined by means of universal calibration with GPC/DV (coupled differential viscometry- GPC) technique. Factors that affect the narrowly distributed linearly extended polymer chain, such as solvent, temperature, promoter, monomer concentration etc., were discussed in terms of molecular weight, molecular weight distribution, polymer conversion and the cyclic oligomer content through GPC and GC analyses. Back-biting occurred either in the bulk or the solution process. However, the presence of a promoter (DMSO or THF) in a proper proportion accelerated the polymerization, and the reaction went to completion in either process before serious back-biting and chain transfer occurred.
- 英文摘要: --
- 中文關鍵字: Anionic Polymerization; Monodispersed Poly Methyl Trifluoropropyl Siloxan; Glass Transition Temperature; Coupled Differential Viscometry
- 英文關鍵字: 陰離子聚合;玻璃轉移溫度;耦合差示黏度計