Abstract
PBZO's having average molecular length of 27,49 and 128 nm were crystallized from dilute solution in conc.H2SO2. At high crystallization temperature, the shorter PBZO (L∼30nm) formed lath shaped lamellar crystals. Electron diffraction indicated that the long axis of the lamella to be along the crystallographic b-axis forming 100 twins, and that the molecular chains was perpendicular to the lamella. High resolution electron micrograph showed that 100 lattice fringe had an orientation distribution and curved within one crystallite. Decrease in crystallization temperature and/or increase in the chain length changed the morphology essentially into flat fibrils. Branchings through repetitive twinning across {100} and [formula-ommited] planes lead to a square network. Vacancies in the fibrillar network were finally filled by post lamellar growth resuting in a mosaic structure, except with PBZO of the longest molecular chain. Oriented rigid cilia on the lamellar surface facilitated the growth rate of daughter crystals and regulated their orientation.
Original language | English |
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Pages (from-to) | 374-378 |
Number of pages | 5 |
Journal | sen'i gakkaishi |
Volume | 54 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jan 1998 |
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Materials Science (miscellaneous)
- Polymers and Plastics
- Industrial and Manufacturing Engineering