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Structure studies of chemically etched poly(ethylene terephthalate) film
Author(s) -
Adams G. C.
Publication year - 1976
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760160317
Subject(s) - materials science , polymer , scanning electron microscope , gel permeation chromatography , ethylene , degradation (telecommunications) , etching (microfabrication) , solvent , composite material , polymer chemistry , organic chemistry , chemistry , telecommunications , layer (electronics) , computer science , catalysis
A macrostructure consisting of 1500 Å long network, elements has been studied in unoriented and oriented poly(ethylene terephthalate) film. The long dimension of the structure is oriented transverse to the stretch direction. A length to width ratio of approximately 10:1 is observed. The structure is observed by scanning electron microscopy after room temperature etching with n‐propylamine under special conditions. Also studied are weight loss measurements for up to 80 hrs of etching and molecular weight degradation by gel permeation chromatography. The induction time before weight loss commences depends on sample elongation and thermal history. A coincidence of the following times are observed: (I) commencement of weight loss, (2) development of a well‐defined macrostructure by SEM, and (3) completion of molecular weight degradation. Therefore, visual evidence of a macrostructure occurs when weight loss has commenced which requires degradation to products soluble in the etchant. The GPC curves vs rich time show that etched film oriented to a crystalline state possesses two molecular weight peaks. The peak for polymer in which no degradation occurred is replaced by a peak for polymer of nine to ten repeat units which is highly crystalline and, therefore, resistant to further attack.