Epitaxial crystallization of polyoxymethylene, polypropylene, and polypropylene oxide from solution on cleaved surfaces of alkali halides

Perfectly Alternating Ethylene−Carbon Monoxide Copolymer Crystallized Epitaxially on Alkali Halides. 1. Morphological Observation by TEM

“…Figure a shows the typical rodlike morphology of POK crytallized epitaxially on the (001) face of NaCl from a nitrobenzene solution ( T c = 180 °C, t c = 5 min). This morphology is closely similar to those observed for polyethylene (PE) and polyoxymethylene (POM) crystals grown on various alkali halides. − ,− The two orthogonal sets of POK rodlike crystals are oriented at 45° to the shadowing direction (the arrow in Figure a), i.e . , parallel to the [110] and [1̄10] directions of the substrate.…”

“…In the present work, rodlike crystals of perfectly alternating ethylene−carbon monoxide copolymer (POK) have been successfully oriented on the (001) cleavage faces of the NaCl and KI single crystals by isothermal crystallization from a 0.01 wt % solution in nitrobenzene. The morphology, with a perpendicular orientation of the deposited rodlike crystals, bears close resemblance to that observed for PE and POM crystals grown on various alkali halides; that is to say, the rodlike crystals of PE and of POM are oriented in the 〈110〉 directions of the substrates. − ,− Though the orthorhombic PE grows favorably on KBr, the monoclinic form grows transiently just on NaCl, and the growth transition to the orthorhombic one occurs within a few nanometers from the NaCl surface. , As for POM, for example, the hexagonal form grows on KCl and NaCl, but the orthorhombic form is mingled with the hexagonal one on KI and KBr . The present TEM study on POK reveals the following: (i) Epitaxial interactions of POK with the NaCl (001) face are rather nonspecific in terms of crystalline phase as well as of contact plane.…”

Preparation Methods for Thin Films

“…Polymer films of materials such as polypropylene, polystyrene (66) and P.V.C. (67) have been obtained by the simple technique of direct isothermal immersion of a substrate into a suitable solution of the polymer, and also by allowing the evaporation of the solvent from the polymer solution placed on a substrate.…”