Dataset Information

Effect of Different Plasticizers on Thermal, Crystalline, and Permeability Properties of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Films.

ABSTRACT: Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) films were prepared using a cast film technique. Dioxane was chosen over other polymer solvents as it resulted in homogenous films with better morphology. Several plasticizers with different molecular weights and concentrations were added to the biopolymer solution prior to casting. Thermal, crystalline, and permeability properties were analyzed by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and both water vapor and oxygen transmission rate analysis. In general, the addition of plasticizers decreased the glass transition temperature (T_g), cold crystallization temperatures (T_cc), melting temperatures, as well as crystallinity degrees and increased the crystallite sizes and water vapor and oxygen transmission rates. The use of isosorbide and low-molecular-weight poly(ethylene glycol) (PEG) lowered the Tg around 30 °C at the highest used concentration, also being the most effective in increasing the crystallite size. When considering isosorbide and low-molecular-weight poly(ethylene glycol) (PEG) as very good plasticizers for PHBH, the question of which plasticizer to use strongly relies on the desired PHBH application.

SUBMITTER: Farrag Y

PROVIDER: S-EPMC9460745 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Effect of Different Plasticizers on Thermal, Crystalline, and Permeability Properties of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Films.

Farrag Yousof Y Barral Luis L Gualillo Oreste O Moncada Danny D Montero Belén B Rico Maite M Bouza Rebeca R

Polymers 20220826 17

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) films were prepared using a cast film technique. Dioxane was chosen over other polymer solvents as it resulted in homogenous films with better morphology. Several plasticizers with different molecular weights and concentrations were added to the biopolymer solution prior to casting. Thermal, crystalline, and permeability properties were analyzed by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XR ...[more]

PMID: 36080578

Similar Datasets

Project description:Poly(hydroxybutyrate-co-hydroxyhexanoate) [P(HB-co-HHx)] and poly(hydroxybutyrate-co-hydroxyvalerate-co-hydroxyhexanoate) [P(HB-co-HV-co-HHx)] demonstrate interesting mechanical and thermal properties as well as excellent biocompatibility, making them suitable for multiple applications and notably biomedical purposes. The production of such polymers was described in Rhodospirillum rubrum, a purple nonsulfur bacteria in a nutrient-lacking environment where the HHx synthesis is triggered by the presence of hexanoate in the medium. However, the production of P(HB-co-HHx) under nutrient-balanced growth conditions in R. rubrum has not been described so far, and the assimilation of hexanoate is poorly documented. In this study, we used proteomic analysis and a mutant fitness assay to demonstrate that hexanoate assimilation involve β-oxidation and the ethylmalonyl-coenzyme A (CoA) (EMC) and methylbutanoyl-CoA (MBC) pathways, both being anaplerotic pathways already described in R. rubrum. Polyhydroxyalkanoate (PHA) production is likely to involve the de novo fatty acid synthesis pathway. Concerning the polymer composition, HB is the main component of the polymer, probably as acetyl-CoA and butyryl-CoA are intermediates of hexanoate assimilation pathways. When no essential nutrient is lacking in the medium, the synthesis of PHA seems to help maintain the redox balance of the cell. In this framework, we showed that the fixation of CO2 is required to sustain the growth. An increase in the proportion of HHx in the polymer was observed when redox stress was engendered in the cell under bicarbonate-limiting growth conditions. The addition of isoleucine or valerate in the medium also increased the HHx content of the polymer and allowed the production of a terpolymer of P(HB-co-HV-co-HHx). IMPORTANCE The use of purple bacteria, which can assimilate volatile fatty acids, for biotechnological applications has increased, since they reduce the production costs of added-value compounds such as PHA. P(HB-co-HHx) and P(HB-co-HV-co-HHx) have demonstrated interesting properties, notably for biomedical applications. In a nutrient-lacking environment, R. rubrum is known to synthesize such polymers when hexanoate is used as the carbon source. However, their production in R. rubrum in non-nutrient-lacking growth conditions has not been described so far, and the assimilation of hexanoate is poorly documented. As the carbon source and its assimilation directly impact the polymer composition, we studied under non-nutrient-lacking growth conditions the assimilation pathway of hexanoate and PHA production in R. rubrum. Proteomic analysis and mutant fitness assays allowed us to explain PHA production and composition. An increase in HHx content of the polymer and production of P(HB-co-HV-co-HHx) was possible using the knowledge gained on metabolism under hexanoate growth conditions.

Dataset Information

Effect of Different Plasticizers on Thermal, Crystalline, and Permeability Properties of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Films.

Publications

Effect of Different Plasticizers on Thermal, Crystalline, and Permeability Properties of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Films.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets