| 학회 | 한국고분자학회 |
| 학술대회 | 2003년 봄 (04/11 ~ 04/12, 연세대학교) |
| 권호 | 28권 1호, p.11 |
| 발표분야 | 고분자 구조 및 물성 |
| 제목 | Rigid Polymer Crystals |
| 초록 | Since the discovery of polyethylene single crystal, the chain folding has been recognized as the main chain conformation in crystalline regions of polymer solid. In recent years, rigid polymers have been synthesized successfully and used mainly for their high performance characteristics, such as high modulus, strength, and temperature resistances. Most of these polymeric chains are able to crystallize, but can not fold. The object of this study is to describe the morphology and structure formed in the crystallization stage of this rigid polymer from dilute solution. The rigid polymer poly(p-phenylene benzobisthiazole) was crystallized from dilute solution. Electron microscopy showed that upon quenching, several nanometer thick, flat fibrils were produced. Subsequent heat treatment in a solvent changed the morphology from fibrillar into "segmented ribbon" structure. Isothermal crystallization resulted in aggregate of rod crystals. The polymer chains are oriented normal to the rod crystals. The width of the rod crystal increased with average molecular length but saturated to a value much smaller than the average molecular length. This saturation means that molecular chains take part in formation of neighboring rod crystals. Based on observation of the morphology and the crystallization process, an isothermal crystallization mechanism is proposed. Because of the rigidity and wide length distribution of polymer chains, the chain ends are inevitably included within the crystals resulting in crystal defects such as axial shifts, lattice curvatures and edge dislocations, all of which were directly observed by lattice imaging. |
| 저자 | Tetsuya Uchida |
| 소속 | Okayama Univ. |
| 키워드 | |
