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

Abstract

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.

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

“…However, the thermal stability is high for all the samples. Decreased stability has been reported for PBSA/LDH samples, 40 for PBS/LDH nanocomposites, 8,12,[16][17][18]20,21,59 as well as for analogous systems, such as poly(propylene carbonate)/MgAl-LDH, poly(ε-caprolactone)/LDH and poly(lactic acid):Zn 3 Al/LDH nanocomposites. [60][61][62] Table 1.…”

“…A large variety of organic anions has been used to intercalate the space between the lamellae in order to organo-modify the hydroxyl platelets and to render them compatible with the polymer chains, as well as to confer specific properties to the matrix, according to the end-use properties required. [8][9][10][11][16][17][18] The use of organic/inorganic (O/I) platelets to improve the rheological properties of a polymer, almost corresponding to an increment of the molecular weight, represents an elegant alternative to the use of typical chain extender molecules mentioned above. LDHs are efficient even at low loadings and can enlarge the possibility of polymer use.…”

“…23 However, some of its inherent shortcomings are a low melt strength and viscosity, as well as low gas barrier properties. Our research group studied PBS as the polymeric matrix in composite materials containing LDH, 8,9,12,[16][17][18][20][21][22] graphene, 24 lignocellulosic fibers [25][26][27][28] and rice endosperm 29 with the aim of improving its technical performances. PBSA is a copolymer of PBS containing a potentially biobased comonomer: dimethyladipate.…”

State-of-the-Art Production Chains for Peas, Beans and Chickpeas—Valorization of Agro-Industrial Residues and Applications of Derived Extracts

“…Aromatic amino acids (such as tryptophan and tyrosine) obtained from the hydrolysis of a protein-rich agricultural waste can also be utilized to impart high UV resistance and UV-shielding features to a polymeric matrix [111]. However, embedding these molecules directly into a polymeric matrix has several drawbacks since they can react with the polymer back-bone giving rise to polymer degradation, or they can leach out of the polymer surface itself.…”

“…However, embedding these molecules directly into a polymeric matrix has several drawbacks since they can react with the polymer back-bone giving rise to polymer degradation, or they can leach out of the polymer surface itself. In order to overcome these drawbacks, a protection strategy using hydrotalcite-like compounds (layered double hydroxides, LDH) has been developed [112] to immobilize the amino acids and using them as fillers to impart UV resistance to the polymer matrix [111]. In addition, bio-based polymers and bio-films obtained also from legume seed proteins were produced to be applied as packaging materials and composites.…”