Crystalline Films of L‐Threonine Complexed with Copper (II) Dispersed in a Galactomannan Solution: A Structural, Vibrational, and Thermal Study

• Published in: Polymer engineering and science 2020-01, Vol.60 (1), p.71-77
• Main Authors: Oliveira Neto, João G., Cavalcante, Lincoln A., Gomes, Eduardo S., Dos Santos, Adenilson O., Sousa, Francisco F, Mendes, Fernando, Macêdo, Ana Angélica M
• Format: Article
• Language: English
• Subjects: Amino acids; Copper; Copper compounds; Crystal structure; Crystallinity; Dehydration; Dehydration (Physiology); Differential thermal analysis; Dispersion; Organic compounds; Polymers; Raman spectra; Raman spectroscopy; Spectroscopy; Spectrum analysis; Thermal properties; Thermal stability; Thermodynamic properties; Thermogravimetry; X-ray diffraction
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.25260

The study's aim was to synthesize a crystalline film formed by L‐threonine crystals complexed with Cu2+ ions (LTCu) dispersed in a galactomannan (Gal) solution as well as to characterize its structural, vibrational, and thermal properties. Gal(LTCu) films were prepared by the addition of copper II L‐threoninate crystals in concentrations of 0.25, 0.50, and 0.75 in 2% Gal solution. To characterize the Gal(LTCu) properties, we used X‐ray diffraction (XRD), UV–Vis and Raman spectroscopy, thermogravimetry, and thermal analyses (TG‐DTA). XRD showed that the Gal(LTCu) films are crystalline and have acquired coloration similar to the one of LTCu crystal. The UV–Vis spectra revealed that the films tend to assume a square planar conformation due to Jahn Teller effect. Bands related to the interaction between the metal ion with the organic compounds were observed through the Raman spectra. TG‐DTA showed that the films exhibit low thermal stability due to the dehydration process. POLYM. ENG. SCI., 60:71–77, 2020. © 2019 Society of Plastics Engineers