Crystallization behavior of polyethylene oxide/para-nitroaniline microdispersed composites

✍ Scribed by C. Saujanya; S. Radhakrishnan

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 357 KB
• Volume: 65
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970808)65:6<1127::aid-app8>3.0.co;2-m

✦ Synopsis

The crystallization behavior of polyethylene oxide (PEO) containing microdispersed nonlinear optical chromophores such as para-nitroaniline (PNA) has been investigated with respect to comopsition and different methods of film preparation techniques viz. solvent casting, melt casting, and powder molding. Large variations in the intensities of major reflections, 012 and 101, from PNA crystallites were observed depending on the composition as well as the method of preparation. The morphology of the samples examined under cross-polarizing conditions revealed highly birefringent crystallites dispersed in the spherulitic morphology of the PEO matrix in contrast to weakly birefrindgent crystals of the additive by itself. At high concentrations exceeding 45 wt % the PNA crystals act as substrates for the growth of polymer crystals. These results have been explained on the basis of intermolecular interaction as well as good lattice match between the crystalizing components, leading to preferential growth of the crystals along a certain direction.