A method for the evaluation of the amount of defects in the comonomer alternation included in the crystalline phase of alternating ethylene-tetrafluoroethylene (ETFE) and ethylene-chlorotrifluoroethylene (ECTFE) copolymers, is proposed. The method is based on a comparison between X-ray fiber diffraction profiles and calculated Fourier transforms for isolated chain models. The proposed method is not affected by the regioirregularities and stereoirregularities possible for ECTFE. For the considered ECTFE sample, the chains in the crystalline phase present an amount of defects in the comonomer alternation much lower than those evaluated for all the considered ETFE samples. Substantial differences in the melting temperatures between ETFE samples are accounted for by the different amounts of defects in the comonomer alternation included in the crystalline phase. (C) 1995 John Wiley and Sons, Inc.
Evaluation of the Amount of Defects In the Comonomer Alternation Included In the Crystal Phase For Ethylene-tetrafluoroethylene and Ethylene-chlorotrifluoroethylene Alternating Copolymers / DE ROSA, Claudio; G., Guerra; C., Daniello; V., Petraccone; P., Corradini; G., Ajroldi. - In: JOURNAL OF APPLIED POLYMER SCIENCE. - ISSN 0021-8995. - STAMPA. - 56:(1995), pp. 271-278. [10.1002/app.1995.070560218]
Evaluation of the Amount of Defects In the Comonomer Alternation Included In the Crystal Phase For Ethylene-tetrafluoroethylene and Ethylene-chlorotrifluoroethylene Alternating Copolymers
DE ROSA, CLAUDIO;
1995
Abstract
A method for the evaluation of the amount of defects in the comonomer alternation included in the crystalline phase of alternating ethylene-tetrafluoroethylene (ETFE) and ethylene-chlorotrifluoroethylene (ECTFE) copolymers, is proposed. The method is based on a comparison between X-ray fiber diffraction profiles and calculated Fourier transforms for isolated chain models. The proposed method is not affected by the regioirregularities and stereoirregularities possible for ECTFE. For the considered ECTFE sample, the chains in the crystalline phase present an amount of defects in the comonomer alternation much lower than those evaluated for all the considered ETFE samples. Substantial differences in the melting temperatures between ETFE samples are accounted for by the different amounts of defects in the comonomer alternation included in the crystalline phase. (C) 1995 John Wiley and Sons, Inc.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
