Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl Groups

Soluble and transparent wholly aromatic polyamides (PAs) were synthesized from an unsymmetrical diamine monomer having trifluoromethyl (CF<sub>3</sub>) groups, 4-(4′-aminophenoxy)-3,5-bis(trifluoromethyl)aniline. The monomer was polymerized with several dicarboxylic acid monomers via the...

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Main Authors: Seong Jong Kim, Inah Kang, Taejoon Byun, Jongho So, Sang Youl Kim
Format: Article
Language:English
Published: MDPI AG 2022-01-01
Series:Polymers
Subjects:
Online Access:https://www.mdpi.com/2073-4360/14/3/501
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author Seong Jong Kim
Inah Kang
Taejoon Byun
Jongho So
Sang Youl Kim
author_facet Seong Jong Kim
Inah Kang
Taejoon Byun
Jongho So
Sang Youl Kim
author_sort Seong Jong Kim
collection DOAJ
description Soluble and transparent wholly aromatic polyamides (PAs) were synthesized from an unsymmetrical diamine monomer having trifluoromethyl (CF<sub>3</sub>) groups, 4-(4′-aminophenoxy)-3,5-bis(trifluoromethyl)aniline. The monomer was polymerized with several dicarboxylic acid monomers via the Yamazaki–Higashi polycondensation method. All of the synthesized polyamides have an amorphous morphology, and they are soluble in many polar organic solvents at room temperature. Flexible and transparent films of the polyamides were prepared by solution casting and these polymer films show good optical transparencies with cut-off wavelengths of 337–367 nm and transparencies of 88%–90% at 550 nm. In addition, all the polymers were thermally stable over 400 °C and exhibited glass transition temperatures (<i>T</i><sub>g</sub>) higher than 300 °C. Unsymmetrically inserted trifluoromethyl groups on polyamides improves the solubility as well as the transparency of the polymers while maintaining good thermal properties. They also showed low refractive indices around 1.5333~1.5833 at 633 nm owing to the existence of low polarizable trifluoromethyl groups.
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spelling doaj.art-7361a271b8a54bf9b88223896a3742992023-11-23T17:34:53ZengMDPI AGPolymers2073-43602022-01-0114350110.3390/polym14030501Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl GroupsSeong Jong Kim0Inah Kang1Taejoon Byun2Jongho So3Sang Youl Kim4Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, KoreaDepartment of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, KoreaDepartment of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, KoreaDepartment of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, KoreaDepartment of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, KoreaSoluble and transparent wholly aromatic polyamides (PAs) were synthesized from an unsymmetrical diamine monomer having trifluoromethyl (CF<sub>3</sub>) groups, 4-(4′-aminophenoxy)-3,5-bis(trifluoromethyl)aniline. The monomer was polymerized with several dicarboxylic acid monomers via the Yamazaki–Higashi polycondensation method. All of the synthesized polyamides have an amorphous morphology, and they are soluble in many polar organic solvents at room temperature. Flexible and transparent films of the polyamides were prepared by solution casting and these polymer films show good optical transparencies with cut-off wavelengths of 337–367 nm and transparencies of 88%–90% at 550 nm. In addition, all the polymers were thermally stable over 400 °C and exhibited glass transition temperatures (<i>T</i><sub>g</sub>) higher than 300 °C. Unsymmetrically inserted trifluoromethyl groups on polyamides improves the solubility as well as the transparency of the polymers while maintaining good thermal properties. They also showed low refractive indices around 1.5333~1.5833 at 633 nm owing to the existence of low polarizable trifluoromethyl groups.https://www.mdpi.com/2073-4360/14/3/501high temperature polymerpolyamidestrifluoromethyl group
spellingShingle Seong Jong Kim
Inah Kang
Taejoon Byun
Jongho So
Sang Youl Kim
Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl Groups
Polymers
high temperature polymer
polyamides
trifluoromethyl group
title Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl Groups
title_full Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl Groups
title_fullStr Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl Groups
title_full_unstemmed Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl Groups
title_short Highly Transparent Aromatic Polyamides from Unsymmetrical Diamine with Trifluoromethyl Groups
title_sort highly transparent aromatic polyamides from unsymmetrical diamine with trifluoromethyl groups
topic high temperature polymer
polyamides
trifluoromethyl group
url https://www.mdpi.com/2073-4360/14/3/501
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