STRUCTURE AND CRYSTALLIZATION OF MOLECULAR-COMPLEXES BETWEEN POLY(ETHYLENE OXIDE) AND HYDROXYBENZENES

Authors
Citation
M. Dosiere, STRUCTURE AND CRYSTALLIZATION OF MOLECULAR-COMPLEXES BETWEEN POLY(ETHYLENE OXIDE) AND HYDROXYBENZENES, Journal of macromolecular science. Physics, B35(3-4), 1996, pp. 303-328
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Polymer Sciences
ISSN journal
0022-2348
Volume
B35
Issue
3-4
Year of publication
1996
Pages
303 - 328
Database
ISI
SICI code
0022-2348(1996)B35:3-4<303:SACOMB>2.0.ZU;2-2
Abstract
The phase diagrams of the binary systems poly(ethylene oxide) (PEO)-re sorcinol and poly(ethylene oxide)-p-nitrophenol show the presence of m olecular complexes with well-defined stoichiometries. The crystal stru cture of these two molecular complexes has been determined from wide-a ngle x-ray diffraction patterns of stretched films and spherulites. Th e morphology of the two complexes crystallized from the melt is invest igated by differential scanning calorimetry and small-angle x-ray scat tering. The crystallization of the PEO-resorcinol complex from the mel t gives integral-folded crystals with either extended chains (EC) or n -folded chains (n-FC). As observed for PEO oligomers, the fraction of EC crystals of the PEO-resorcinol complex increases with the crystalli zation temperature to give finally only EC crystals but in a larger ra nge of crystallization temperatures than for pure PEG. On the other ha nd, the PEO-p-nitrophenol complex crystallizes over all the studied cr ystallization range as stable nonintegral-folded (NIF) crystals. Two p roposals related to the crystal structure of these complexes and their mode of growth are invoked to explain these two greatly different mor phologies at the lamellar level.