Inorganic-Organic Hybrid Materials Based on Amino Acid Modified Hydrotalcites Used as UV-Absorber Fillers for Polybutylene Succinate

Strategy of Integrating Ultraviolet Absorption and Antimicrobial Activity in a Single Molecule: DFT Calculation and Experiment

In the present study, (3,5-benzamide-2,4-dihydroxyphenyl)(phenyl) methanone (UV-CB) was synthesized and investigated as an ultraviolet (UV) absorber and a bacteriostatic agent. The optimized geometry, energy levels, charges, and UV electronic absorption bands of UV-CB in the singlet were calculated by density functional theory (DFT) calculations. The quantum chemical method was used to investigate the geometry and natural bond orbital (NBO) parameters. And the computational studies indicated that the intramolecular hydrogen bond (IMHB) was formed between the 2,4-dihydroxybenzophenone (UV-C) group and the N-(hydroxymethyl)benzamide (NBA) group, which was beneficial to the stability after the combination. The results of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests illustrated that UV-CB is a promising antibacterial agent. The successful synthesis of UV-CB with anti-UV performance and antibacterial ability evidences that DFT calculation is an available approach to design and analyze novel compounds.

Chain extender effect of 3-(4-hydroxyphenyl)propionic acid/layered double hydroxide in biopolyesters containing the succinate moiety

3-(4-Hydroxyphenyl)propionic acid intercalated in Mg₂Al/layered double hydroxide has been used as a filler in biopolyesters containing the succinate moiety, with the aim of inducing a chain extender effect.

Outstanding chain-extension effect and high UV resistance of polybutylene succinate containing amino-acid-modified layered double hydroxides

Polybutylene succinate (PBS) nanocomposite materials were prepared using a melt compounding process. The Mg₂Al-based PBS nanocomposites, dispersed with inorganic-organic hybrid materials (layered double hydroxides, LDHs), were functionalized with the amino acids L-histidine (HIS) and L-phenylalanine (PHE). The rheological and anti-ultraviolet (anti-UV) properties were investigated and compared to filler-free PBS as well as LDH Mg₂Al/nitrate as references. Both organo-modified LDHs exhibited a remarkable chain-extension effect for PBS with an outstanding increase in the zero-shear viscosity η₀ for PBS-Mg₂Al/PHE (two order of magnitude increase as compared to filler-free PBS). These results were compared to data found in the literature. Moreover, HIS and PHE anions embedded into the LDH structure can successfully prevent the chain scission reactions that usually occur during photo-ageing of PBS under UV radiation exposure. This highlights the outstanding performance of the LDH hybrid materials, and in particular, their application as a polymer chain extender and UV stabilizer for PBS, which can likely be extended to other biodegradable polymers.