Neoteric Solvent Systems as Sustainable Media for Dissolution and Film Preparation of Poly-[(R)-3-hydroxybutyrate]

Abstract

Polyhydroxyalkanoates (PHAs) have a wide range of applicability due to their biodegradable and biocompatible characteristics. This makes them suitable for commercialization as an alternative to petroleum-based synthetic plastics. Solvents such as chloroform are reported to solubilize polyhydroxyalkanoates. With chloroform being hazardous for both health and the environment, this work attempts to replace this chlorinated solvent with green solvents like ionic liquids. In this study, poly-[(R)-3hydroxybutyrate] (PHB) was extracted from Halomonas hydrothermalis, and its solubility, stability, and film-forming ability were investigated in the presence of ammonium-based ionic liquids (ILs). Among the studied ILs, maximum solubility (3% w/v at 70 °C) along with chemical and structural stability of the polymer was observed in diethanol ammonium acetate (DA), while the lowest dissolution (0.4% w/v) was exhibited in 2-hydroxyethylammonium formate (HF). The molecular docking studies have established a critical role of the anions of the ILs in the dissolution process. Further, PHB dissolved in DA formed a film in the presence of gelatin (G). The recovered ILs were found to be soil compatible, and due to their high nitrogen content, they can be used as a fortifier for nitrogen-deficient seaweed-based liquid plant biostimulants making them suitable soil nutrients for agriculture applications.

Effective and Sustained Control of Soil-Borne Plant Diseases by Biodegradable Polyhydroxybutyrate Mulch Films Embedded with Fungicide of Prothioconazole

“…The pot experiment showed that the growth of peanut seedlings covered with a blank PHB film was better than that of peanut seedlings without a PHB film cover ( Figure 12 ). The degradation of PHB has a certain nutritional effect on the growth of plants [ 29 ]. With the increase of PRO/PHB antifungal film content, the root length, fresh weight, and dry weight of peanut seedlings increased slightly and then decreased.…”

Efficient Production of Polyhydroxyalkanoate Through Halophilic Bacteria Utilizing Algal Biodiesel Waste Residue

“… Dubey et al, 2017 reported the extraction of PHA utilizing green solvents. Also, the dissolution of PHA was reported in green solvent diethanol ammonium acetate with maximum solubility of 3% w/v at 70°C ( Sequeira et al, 2020 ). Herein, the extracted polymer showed good thermal and mechanical properties compared to standard PHB from Sigma Aldrich.…”

Sustainable Production of Quaternary Ammonium Seaweed Polysaccharide Salts and Their Evaluation for Seed Dressing in Agricultural Applications

“…Therefore, aqueous solutions of QASs were investigated for their ability to dissolve alginic acid. The cloud point method was used to determine the dissolution extent of alginic acid following the steps previously reported by us. , In a typical experiment, the dissolution efficiencies of the aqueous solutions of QASs were studied by adding desired amounts of alginic acid in each of them, first at room temperature (RT = 27 °C) and then gradually increasing temperature up to 70 °C (only for those solutions that showed insolubility at RT) with stirring under an atmosphere of nitrogen until a clear homogeneous solution is obtained. An optical microscope (100×) (Figure S1, Supporting Information) was used to observe the aliquots, and the absence of insoluble fibers of alginic acid with a gradual increase in reaction time in the respective solutions confirmed complete dissolution of the seaweed polysaccharide.…”

“…Total microbial load count in the presence of TMAA was done using soil bacteria following the method reported earlier by us. 33 Soil samples were collected from pot culture experiment sites of CSIR-CSMCRI. 1 g of TMAA was dissolved in 50 mL of distilled water (test sample).…”