Selective etching of thermotropic liquid crystalline polyesters

Hedmark, Per G. (author): Department of Polymer Technology, The Royal Institute of Technology, Stockholm, Sweden

Jansson, Jan-Fredrik (author): Department of Polymer Technology, The Royal Institute of Technology, Stockholm, Sweden

Hult, Anders (author): Department of Polymer Technology, The Royal Institute of Technology, Stockholm, Sweden

Lindberg, Henrik (author): Department of Polymer Technology, The Royal Institute of Technology, Stockholm, Sweden

Gedde, Ulf W. (author): Department of Polymer Technology, The Royal Institute of Technology, Stockholm, Sweden

(creator_code:org_t)

Wiley, 1987
1987
English.
In: Journal of Applied Polymer Science. - : Wiley. - 0021-8995 .- 1097-4628. ; 34:2, s. 743-762

Related links:: https://urn.kb.se/re...; show more...; https://doi.org/10.1...; show less...

Abstract Subject headings

DSC, IR, ESCA, macroscopic etching rate measurements, analysis of etchant solution, and electron microscopy conclusively show that n-alkylamines (ethylamine, n-propylamine, n-butylamine, and n-pentylamine) and NaOH selectively degrade (etch) the ethylene terephthalate (ET)-rich phase in glassy liquid crystalline poly(p-hydroxybenzoic acid-co-ethylene terephthalate) [P(HBA-ET)] with molar compositions 0.60:0.40 and 0.80:0.20. ESCA demonstrates the excellent selectivity of the n-alkylamine etchants in the 0.60:0.40 copolymer. The 50 Å top layer of the etched samples contains 95 mol% HBA. Treatment with H2SO4 and NH3 gives ambiguous results, and these compounds are not suitable as etchants. It is demonstrated by electron microscopy on the 0.60:0.40 copolymer, in accordance with earlier reports by Joseph et al.,5-8 that the ET-rich phase is discontinuous (1-2 m spheres) and surrounded by an HBA-rich matrix. SEM is a useful tool for characterization of this morphology. However, both phases have a substracture which is revealed only by TEM. The morphology of the 0.80:0.20 copolymer is fine-textured, which means that SEM is a less suitable method for the characterization of etched samples.

DSC, IR, ESCA, macroscopic etching rate measurements, analysis of etchant solution, and electron microscopy conclusively show that n-alkylamines (ethylamine, n-propylamine, n-butylamine, and n-pentylamine) and NaOH selectively degrade (etch) the ethylene terephthalate (ET)-rich phase in glassy liquid crystalline poly(p-hydroxybenzoic acid-co-ethylene terephthalate) [P(HBA-ET)] with molar compositions 0.60:0.40 and 0.80:0.20. ESCA demonstrates the excellent selectivity of the n-alkylamine etchants in the 0.60:0.40 copolymer. The 50 Å top layer of the etched samples contains 95 mol% HBA. Treatment with H2SO4 and NH3 gives ambiguous results, and these compounds are not suitable as etchants. It is demonstrated by electron microscopy on the 0.60:0.40 copolymer, in accordance with earlier reports by Joseph et al.,5-8 that the ET-rich phase is discontinuous (1-2 m spheres) and surrounded by an HBA-rich matrix. SEM is a useful tool for characterization of this morphology. However, both phases have a substracture which is revealed only by TEM. The morphology of the 0.80:0.20 copolymer is fine-textured, which means that SEM is a less suitable method for the characterization of etched samples.

By the author/editor: Hedmark, Per G.; Jansson, Jan-Fre ...; Hult, Anders; Lindberg, Henrik; Gedde, Ulf W.

About the subject

ENGINEERING AND TECHNOLOGY: ENGINEERING AND ...; and Industrial Biote ...; and Bio Materials

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