Synthesis and characterization of polyesters derived from succinic acid, ethylene glycol and 1,3-propanediol

PHB Processability and Property Improvement with Linear-Chain Polyester Oligomers Used as Plasticizers

In 2021, global petroleum-based plastic production reached over 400 million metric tons (Mt), and the accumulation of these non-biodegradable plastics in the environment is a worldwide concern. Polyhydroxybutyrate (PHB) offers many advantages over traditional petroleum-based plastics, being biobased, completely biodegradable, and non-toxic. However, its production and use are still challenging due to its low deformation capacity and narrow processing window. In this work, two linear-chain polyester oligomers were used as plasticizers to improve the processability and properties of PHB. Thermal analyses, XRD, and polarized optical microscopy were performed to evaluate the plasticizing effect on the PHB and the reflection on the mechanical behavior. Both oligomers acted as PHB plasticizers, with a reduction in T_g and T_m as a function of the plasticizer concentration, which can make it easier to handle the material in thermal processing and reduce the probability of thermal degradation. Plasticizer 2 proved to be the most promising between the two with an optimized condition of 20%, in which there was a decrease in elastic modulus of up to 72% and an increase in the maximum elongation of 467%.

Preparation of biacidic tin-based ionic liquid catalysts and their application in catalyzing coupling reaction between ethylene carbonate and dimethyl succinate to synthesize poly(ethylene succinate)

A new low-carbon and environmentally friendly process method for the catalytic synthesis of biodegradable polyester by utilizing ionic liquid catalysts.

The Effect of Molecular Weight on the Solubility Properties of Biocompatible Poly(ethylene succinate) Polyester

Poly(ethylene succinate) (PES) is one of the most promising biodegradable and biocompatible polyesters and is widely used in different biomedical applications. However, little information is available on its solubility and precipitation properties, despite that these solution behavior properties affect its applicability. In order to systematically study these effects, biodegradable and biocompatible poly(ethylene succinate) (PES) was synthesized using ethylene glycol and succinic acid monomers with an equimolar ratio. Despite the optimized reaction temperature (T = 185 °C) of the direct condensation polymerization, relatively low molecular mass values were achieved without using a catalyst, and the Mn was adjustable with the reaction time (40-100 min) in the range of ~850 and ~1300 Da. The obtained crude products were purified by precipitation from THF ("good" solvent) with excess of methanol ("bad" solvent). The solvents for PES oligomers purification were chosen according to the calculated values of solubility parameters by different approaches (Fedors, Hoy and Hoftyzer-van Krevelen). The theta-solvent composition of the PES solution was 0.3 v/v% water and 0.7 v/v% DMSO in this binary mixture. These measurements were also allowed to determine important parameters such as the coefficients A (=0.67) and B (=3.69 × 104) from the Schulz equation, or the Kη (=8.22 × 10-2) and α (=0.52) constants from the Kuhn-Mark-Houwink equation. Hopefully, the prepared PES with different molecular weights is a promising candidate for biomedical applications and the reported data and constants are useful for other researchers who work with this promising polyester.

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.

Biotic and Abiotic Synthesis of Renewable Aliphatic Polyesters from Short Building Blocks Obtained from Biotechnology

Biobased polymers have seen their attractiveness increase in recent decades thanks to the significant development of biorefineries to allow access to a wide variety of biobased building blocks. Polyesters are one of the best examples of the development of biobased polymers because most of them now have their monomers produced from renewable resources and are biodegradable. Currently, these polyesters are mainly produced by using traditional chemical catalysts and harsh conditions, but recently greener pathways with nontoxic enzymes as biocatalysts and mild conditions have shown great potential. Bacterial polyesters, such as poly(hydroxyalkanoate)s (PHA), are the best example of the biotic production of high molar mass polymers. PHAs display a wide variety of macromolecular architectures, which allow a large range of applications. The present contribution aims to provide an overview of recent progress in studies on biobased polyesters, especially those made from short building blocks, synthesized through step-growth polymerization. In addition, some important technical aspects of their syntheses through biotic or abiotic pathways have been detailed.

Biobased copolyesters from renewable resources: synthesis and crystallization behavior of poly(decamethylene sebacate-co-isosorbide sebacate)

A series of biobased copolyesters poly(decamethylene sebacate-co-isosorbide sebacate) are synthesized and their crystallization behavior is explored.

Biobased copolyesters from renewable resources: synthesis and crystallization kinetics of poly(propylene sebacate-co-isosorbide sebacate)

The thermal properties and crystallization kinetics of a novel bio-based poly(propylene sebacate-co-isosorbide sebacate) copolyesters are explored.