POLYMER DECORATION STUDY IN CHAIN FOLDING BEHAVIOR OF SOLUTION-GROWN POLY(ETHYLENE OXIDE) CRYSTALS

The polymer decoration method based on the vaporization and condensati on-crystallization of polyethylene (PE) upon the fold surface of polym er crystals has been widely used to study the chain folding behavior o f the crystals. When this method was utilized to study solution-grown high molecular weight poly(ethylene oxide) (PEG) lamellar crystals, th e highly anisotropic, low molecular weight fragment PE decorated becom e oriented parallel to the fold direction and form rods, which can be observed by transmission electron microscopy (TEM) and electron diffra ction (ED). The growth sectors were clearly observed. From the ED patt erns the {200} planes of the orthorhombic low molecular weight PE rod crystals can be observed, and the c-axis of these crystals is aligned parallel to the {120} growth planes of the PEO crystals. The decoratio n results indicate that the major fold orientation of high molecular w eight PEO single crystals grown from dilute solution is along the {120 } planes. (C) 1995 John Wiley and Sons, Inc.