Abstract
A novel thermotropic liquid crystalline polymers poly{3-benzylidene amino-4-hydroxybenzoic acid (3,4-BAHBA)-co-trans-4-hydroxycinnamic acid (4HCA: trans-coumaric acid)} (Poly(3,4-BAHBA-co-4HCA)), was synthesized by the thermal polycondensation of 4HCA and 3,4-BAHBA, which was synthesized by a reaction of 3-amino-4-hydroxybenzoic acid (3,4-AHBA) with benzaldehyde. When the 4HCA compositions of Poly(3,4-BAHBA-co-4HCA)s were above 55 mol%, the copolymers showed a nematic, liquid crystalline phase. Differential scanning calorimetry (DSC) measurements of the copolymers showed a high glass transition temperature of more than 100 °C, sufficient for use in engineering plastics. Furthermore, the copolymers showed photoluminescence in an N-methylpyrrolidone (NMP) solution under ultraviolet (UV) light with a wavelength of 365 nm. Oriented film of Poly(3,4-BAHBA-co-4HCA) with a 4HCA composition of 75 mol% emitted polarized light, which was confirmed by fluorescent spectroscopy equipped with parallel and crossed polarizers.
Highlights
Liquid crystalline (LC) polymers are oriented at the molecular level to create materials with ultrahigh-strength, a high modulus, and other orientation-related functions [1,2]
We report the synthesis and characterization of the copolymer poly{3-benzylidene amino-4-hydroxybenzoic acid (3,4-BAHBA)-co-trans-4-hydroxycinnamic acid (4HCA: trans-coumaric acid)} (Poly(3,4-BAHBA-co-4HCA)). 3,4-BAHBA is a functional biomonomer synthesized by the reaction of benzaldehyde with 3-amino-4-hydroxybenzoic acid (3,4AHBA), which can be extracted from Streptomyces griseus, a microorganism suitable for the mass-production of various biomolecules [17]. 3,4-BAHBA has a Schiff-based moiety showing visible light absorption and rigid components, and 4HCA is a suitable comonomer for the production of high-performance polymers
The monomer 3,4-BAHBA was synthesized by the reaction of 3,4-AHBA with benzaldehyde (Scheme 1)
Summary
Liquid crystalline (LC) polymers are oriented at the molecular level to create materials with ultrahigh-strength, a high modulus, and other orientation-related functions [1,2]. Polymers 2011, 3 poly(p-phenylene terephthalamide) (KevlarTM) and poly(p-phenylene-2,6-benzobisoxazole) (ZylonTM), which have a high proportion of rigid aromatic moieties, showed lyotropic liquid crystals that could be induced to prepare highly-oriented fibers [3,4]. They are widely used as electrical insulation, protective clothing, straps, cables, and aerospace materials. 3,4-BAHBA has a Schiff-based moiety showing visible light absorption and rigid components, and 4HCA is a suitable comonomer for the production of high-performance polymers.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
