Solvent induced crystallization behavior of poly(ethylene 2,6-naphthalate)film

The relationship between the diffusion behavior and the solvent induced cry stallization (SINC) was investigated. We have also studied the crystalline structures of PEN crystallized by solvent and compared them with those of t hermally crystallized PEN. The diffusion behavior of dioxane at 40 degrees C and 60 degrees C is not pure Fickian but apparent Fickian where diffusion is controlled by crystallization. The diffusion behavior at 25 degrees C i s also not pure Case II. The diffusion behavior in DMF is similar to that i n dioxane. The samples treated in dioxane above 40 degrees C, which show th e Fickian diffusion behavior, exhibit alpha-crystal and spherulitic texture . The sample treated in dioxane at 25 degrees C, which show the Case II dif fusion behavior, mainly exhibits beta-crystal and the amoebae structure. Th e samples treated with DMF mainly show the alpha-crystal, irrespective of t reatment temperature. The change of diffusion behavior by varying the treat ment temperature affects the crystallization conditions? and crystalline fo rm in SING is changed by the characteristic of solvent. (C) 1999 Elsevier S cience Ltd. All rights reserved.