| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 가을 (10/13 ~ 10/14, 제주 ICC) |
| 권호 | 30권 2호 |
| 발표분야 | 기능성 고분자 |
| 제목 | Solid State Polymerization of Polycarbonate oligomers : Effect of Branched Ketones |
| 초록 | Polycarbonates are the most important commercially available high temperature polymers. They have many advantages including various applications over wide range of temperature, excellent mechanical properties, excellent electrical properties, excellent thermal properties and excellent solvent resistance. Aromatic polycarbonates are prepared by reacting 2,2-bis(4-hydroxyphenyl)propane (Bisphenol-A or BPA) with a carbonic ester forming compound such as phosgene or diphenyl carbonate. Aromatic polycarbonate resin produced using Bisphenol-A is used as a raw material for electric and electronic equipments and optical equipments in many cases because of good balance of transparency and mechanical strength with moldability. Polycarbonates are widely used for the fabrication of optical data recording media, including optical disks as exemplified by compact audio disks and CD-ROM disks. Polycarbonates are generally prepared by interfacial polymerization and melt polymerization techniques. However, both the techniques have some advantages and disadvantages. Solid state polymerization (SSP) technology is expected to provide several advantages to the melt polymerization technology currently used. The polycarbonate generated via SSP has a milder thermal history, resulting in the expectation of lower thermal degradation products. The lower thermal degradation generate high purity, moderate to high molecular weight polycarbonate with uses in applications requiring optical clarity and lower hydroxyl end groups. SSP involves a first step of forming a prepolymer, typically by melt polymerization (i.e. transesterification) of a dihydroxyaromatic compound such as Bisphenol-A with a diaryl carbonate such as diphenyl carbonate, a second step of crystallizing the prepolymer and a third step of building the molecular weight of the crystallized prepolymer by heating to a temperature between its glass transition temperature and its melting temperature. Use of this method is of increasing interest by reason of its effectiveness and environmental benefits. In the present work, the effect of different non-solvents namely, acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK) was studied on the crystallization and solid state polymerization of polycarbonate oligomer. A significant decrease in the rate of solid state polymerization was observed with an increase in the branching in ketones and furthermore the rate of crystallization and solid state polymerization of polycarbonate oligomer is dependent on the solubility parameter of acetone, methyl ethyl ketone and methyl isobutyl ketone used in this study. |
| 저자 | 바스카 이드게, 오형석, 김용석, 이성구, 이재흥 |
| 소속 | 한국화학(연) |
| 키워드 | polycarbonate; bisphenol-A; diphenyl carbonate; branched ketones; crystallization; solid state polymerization |
