Molecular Weight Polydispersity Research Articles

Evaluation of Grafting Parameters of Styrene onto Alkaline Modified Sugarcane Bagasse using Fe2+/H2O2 and Fe2+/H2O2-N2H4 initiator systems and Characterization of the Hydrolyzed Grafted Polystyrene Chains

Cellulose the most abundant natural fibre can be modified, via grafting with vinyl monomers, in homogenous or heterogeneous reaction medium. Therefore, the objective of this paper was to study the grafting parameters of styrene onto alkaline modified sugarcane bagasse using Fe2+/H2O2 and Fe2+/H2O2- N2H4 initiator systems and characterized the hydrolyzed grafted polystyrene chains for their viscometry and average molecular weight distributions using standard appropriate methods. The grafting parameters increases within 0.10-0.25 M styrene concentration in both initiator systems and initiator concentration within the range 1.0x10-3 to 6.0x10-3 for Fe2+/H2O2- N2H4 and 1.0x10-3 to 9.0x10-3 for Fe2+/H2O2 systems, albeit with higher values in the former system. These parameters decrease at higher monomer and initiator concentrations in both systems. The viscometry of hydrolyzed polystyrene chain prepared at optimum initiator concentrations and 0.10-0.30 M styrene concentration in both initiator systems are in the range (1.6416-4.5327 cP), (0.6416-3.5327 cP) and (73.2277-202.1927 cP) for relative, specific and inherent viscosities respectively, consistent with increases in activation energy of flow (1.24-5.30 KJmol-1) and average viscosity molecular weights (307.92-565.79 gmol-1) , these parameters decreases at higher monomer concentration in both initiator systems. The number and weight-average molecular weight distributions and polydispersity indices indicates that grafted polystyrene chains in Fe2+/H2O2 system are broader and more polydispersed than those for Fe2+/H2O2- N2H4 initiator system. The results showed that the hydrazine enhanced initiator system was more effective for the copolymerization reaction with polystyrene polydispersity indices comparable to those of synthetic chain-growth polymers.

Effects of different penetration‐grade asphalt binders on the microstructure, mechanical, and aging properties of cold‐mixed epoxy asphalt binder

AbstractThe aim of this research was to investigate asphalt effects on the storage stability, mechanical properties and micro‐properties of cold‐mixed epoxy asphalt binder (CEAB). Firstly, four CEAB were prepared with four base asphalt types and storage stability, miscibility analyses were performed by fluorescence microscopy (FM). Then, cured CEAB and epoxy resin (ER) were treated by ultraviolet aging. Tensile test, dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy were applied to clarify the mechanical properties and micro‐properties of aged and unaged CEAB. Also, bending beam rheometer (BBR) tests were conducted to study low‐temperature performance of CEAB. The results revealed that the CEAB prepared with asphalt with penetration grade 60 ~ 80 presented superior storage stability, miscibility, mechanical properties and that prepared with penetration graded 80 ~ 100 showed slightly better low‐temperature performance. Moreover, asphalt properties were found to have little impacts while epoxy resin played a key role in the mechanical properties of CEAB. Glass transition temperature () of the CEAB containing penetration‐graded asphalt 80 ~ 100 decreased more significantly than that with penetration‐graded asphalt 60 ~ 80, and it was also found that the CEAB prepared with base asphalt with higher molecular weight polydispersity index had better ductility performance.

The Gibbs and Butler Equations and the Surface Activity of Dilute Aqueous Solutions of Strong and Weak Linear Polyelectrolyte-Surfactant Mixtures: The Roles of Surface Composition and Polydispersity.

In a previous paper, we applied a combination of direct measurements of both surface tension and surface excess in conjunction with the Gibbs equation to explain features of the adsorption and surface tension of mixtures of surfactants and strong linear polyelectrolytes at the air-water interface. This paper extends that model by including (i) the restrictions of the Butler equation for the behavior of the surface tension of mixed systems and (ii) the surface behavior of surfactant and linear weak polyelectrolyte mixtures, for which the inclusion of measurements of the surface excess and composition is shown to be particularly important. In addition, a closer examination of earlier data at higher concentrations provides evidence that the surface layering that is often observed in polyelectrolyte-surfactant systems is also an average equilibrium phenomenon and is driven by particular aggregation patterns that occur in some systems and not in others. Although the successful application of the Gibbs and Butler equations indicates that strong polyelectrolyte-surfactant systems can be described in terms of an average equilibrium over wide ranges of concentration, we have identified two concentration ranges where polydispersity in either polyelectrolyte molecular weight or composition results in significant time dependence of the surface behavior.

The Effect of Weakly Coordinating Solvent and Counter Anion on Diphosphine‐Palladium(II) Catalytic Reactivity for Copolymerization of 1‐Butene with Carbon Monoxide in Aqueous Media

AbstractWater soluble bis(acetonitrile) diphospalladium (II) complexes cis‐[Pd(L1–L5)(NCCH3)2][BF4]2 (C1–C5) were obtained by the reaction [Pd(NCCH3)4][BF4]2 with diphosphines ligands L1–L5 (CH2(CH2PR2)2: where R=(CH2)nP(O)(OEt)2, n=2–4, n=6 and n=8)) in dichloromethane–acetonitrile. The isolated complexes were characterized by elemental analysis, FTIR, 1H‐ and 31P‐NMR spectroscopy. The complexes were applied as catalysts for the copolymerization of 1‐butene with carbon monoxide in aqueous media. The present work emphasized on the effect of weakly coordinated solvent and counterion on the catalytic behavior of cis‐[Pd(L1–L5)(NCCH3)2][BF4]2 complexes compared to previously prepared cis‐[ Pd(L1–L5)(OAc)2] (A1–A5). The exchange of π‐bonding NCCH3 ligand with π‐bonding CO and alkene was more favored than the exchange of σ‐bonding OAc− as reflected by the much higher catalytic activity (TON) of the former compared to the latter. In order to compare the catalytic efficiency of water soluble complexes with the performance of a standard, the water insoluble complex, cis‐[Pd(CH2(CH2P(CH2CH3)2)2(NCCH3)2][BF4]2, C6, was prepared and incorporated in the investigations. The isolated alternating 1‐butene/CO copolymer exhibits glass transition temperature of Tg=−3–−15 °C, which is in the range desirable for latex emulsion application. The solid content is up to 21 % with high molecular weight (Mw=4×104 g mol−1) and narrow polydispersities (Mw/Mn=2–3). The C5 complex was found to be fourteen times more active in aqueous polymerization medium (6369 mol substr. mol Pd−1 h−1) than C6 complex in nonaqueous medium (441 mol substr. mol Pd−1 h−1).

Solvent Fractionation of Technical Lignin Materials with Industrially Relevant Solvents

Lignin fractionation aims at dividing the original lignin material into more uniform fractions that have the qualities desired for further processing of the material. Solvent fractionation is a versatile method that produces a soluble and an insoluble fraction with varying compositions, including molecular weight distribution, polydispersity (PDI), and phenolic hydroxyl (OHph) content. These properties are key factors in the further downstream applicability of lignin. Kraft, organosolv, and hydrolysis lignins were fractionated using multiple solvents and their water solutions with a single-stage fractionation protocol. The produced fractions were analyzed for their molecular size distribution and OHph content. Soluble fractions were discovered with desirable qualities, including a narrow size distribution (lowest PDI 1.4) and accumulation of OHph groups (up to 3.05 mmolOH/glignin). Three fractionation solvents, i.e., pure isopropanol, pure ethanol, and 30% γ-valerolactone, were found to produce solvent-specific soluble fractions that had relatively identical characteristic Mw, Mn, and PDI values regardless of the initial lignin material. This is crucially important new data that is beneficial for robust lignin applicability at industrial scale. Other important observations were made regarding water-alcohol solutions, as the increase in initial solid content resulted in changes in the composition of the fractions produced. Further applicability of the obtained fractions is examined in this paper. Patterns as well as differences between the three lignin materials were observed in their dissolution and the resulting compositions of the soluble fractions. This wide comparable dataset of industrially relevant solvents and lignin materials provides significant insight into the possibilities of lignin downstream processing.

Microwave‐Assisted Extraction of Polysaccharides From the Abelmoschus sagittifolius: Optimization, Structure, and Bioactivity

The aim of this study was to extract polysaccharides from Abelmoschus sagittifolius using the microwave‐assisted extraction (MAE) method. Three independent variables, including extraction temperature, microwave power, and microwave time, were chosen for investigation through single‐factor experiments. Response surface methodology (RSM) based on a Box‐Behnken design (BBD) was utilized to optimize the extraction conditions. The study found that the optimal conditions for polysaccharide extraction were a temperature of 63°C, a microwave power of 650 W, and a duration of 58 min. The polysaccharide yield under these conditions was 29.8 g/100 g, closely matching the experimental yield of 30.1 g/100 g. This yield was approximately 1.15 times higher than the yield achieved through conventional extraction methods (heat reflux extraction (HE) method). The study also demonstrated that polysaccharides extracted using the MAE method exhibited improved antioxidant capacity and enzyme inhibition and displayed significant inhibitory effects on HepG2 cells compared to the conventional extraction method. Moreover, the polysaccharides obtained from the optimized MAE process had a lower molecular weight and higher polydispersity than the HE method. These findings indicate that MAE is a promising, efficient, and environmentally friendly technology for extracting polysaccharides from A. sagittifolius.

Nanoscale Self-Assemblies from Amphiphilic Block Copolymers as Proficient Templates in Drug Delivery

This review article emphasizes the current enlargements in the formation and properties of the various nanostructured aggregates resulting from the self-assembly of a variety of block copolymers (BCPs) in an aqueous solution. The development of the different polymerization techniques which produce polymers with a desired predetermined molecular weight and low polydispersity is investigated with regard to their technological and biomedical applications; in particular, their applications as vehicles for drug delivery systems are considered. The solution behavior of amphiphilic BCPs and double-hydrophilic block copolymers (DHBCs), with one or both blocks being responsive to any stimulus, is discussed. Polyion complex micelles (PICMs)/polymersomes obtained from the electrostatic interaction of a polyelectrolyte-neutral BCP with oppositely charged species are also detailed. Lastly, polymerization-induced self-assembly (PISA), which forms nanoscale micellar aggregates with controlled size/shape/surface functionality, and the crystallization-driven self-assembly of semicrystalline BCPs facilitated when one block of the BCP is crystallizable, are also revealed. The scalability of the copolymeric micelles in the drug delivery systems and pharmaceutical formations that are currently being used in clinical trials, research, or preclinical testing is emphasized as these micelles could be used in the future to create novel nanomedicines. The updated literature and the future perspectives of BCP self-assembly are considered.

Diffusion NMR of Poly(acrylic acid) Solutions: Molar Mass Scaling and pH‐Induced Conformational Variation

AbstractSelf‐diffusion of poly(acrylic acid) (PAA) in dilute solution is studied by pulsed field gradient (PFG)‐NMR, also known as DOSY, and correlated to molecular weight with scaling laws at varying pH. Fitting a diffusion coefficient distribution model to PFG‐NMR data, the molecular weight polydispersity of commercial PAA samples is quantified. Due to good agreement with GPC data, diffusion measurements offer a viable alternative to estimate chain length properties with minimal sample preparation. Similar results are achieved by dynamic light scattering (DLS), however, with lower precision. The evolution of the scaling exponent with increasing pH indicates a transition from a globular state in highly acidic conditions (ν = 0.46) to a partially stretched conformation with a maximum at pH 5 (ν = 0.67). At higher pH, counterion screening counteracts chain expansion, while an unexpected increase in the width of the diffusion coefficient distribution occurs. A universal scaling law of the diffusivity applies for a chain length range of 25 ≤ N ≤ 1585, albeit with distinctly different scaling exponents. While opposing arguments are brought forward in recent literature concerning the pH‐dependence of short‐chain conformations, analysis supports the view that chain conformation is significantly affected by pH, even for short chains.

Synthesis and Reduction of Nitrogen-Substituted Diaryl Dihydrophenazine Diradical Dications.

A one-pot synthetic approach to form core-extended N,N'-disubstituted diaryl dihydrophenazine (DADHP) diradical dications (DRDCs) via chemical oxidation from aryl-substituted ortho-phenyldiamines is reported. The isolated N,N'-disubstituted DADHP DRDCs were reduced to their neutral counterparts with hydrazine. The model system featuring an unsubstituted fluorene aryl group, 2a, was tested as a photocatalyst for the polymerization of methyl methacrylate using organocatalyzed atom transfer polymerization (O-ATRP), which yielded a polymer with a controlled molecular weight and narrow polydispersity.

Continuous Addition Terpolymerization of Maleic Anhydride, Octadecyl Acrylate, and Docosyl Acrylate: Experimenting the Terpolymers as Pour Point Depressants for Waxy Crude Oils

Owing to their large specific surface areas and excellent heat and mass transfer compared with those of conventional batch reactors, microreactors have been widely used in chemical industries. In this study, a strategy is proposed for precisely controlling the synthesis of comb-type terpolymers in a microreactor. Poly(octadecyl acrylate–docosyl acrylate–maleic anhydride) was investigated as a pour point depressant (PPD) for waxy crude oils. A terpolymer showing a high weight-average molecular weight (Mw) and low polydispersity index (PDI) was synthesized within 5 min compared with a conventional time-consuming batch reaction. Under the optimal conditions, the Mw of the terpolymer reached 3.7 × 104, and the PDI was 1.42. Notably, the pour point of the crude oil was reduced by 8 K at a PPD dosage of 1300 ppm. The polymerization kinetics revealed that the microreactor accelerated the polymerization. In contrast to the batch reactor, the microreactor exhibited better heat transfer, which avoided the generation of hot spots. Furthermore, the calculated Bodenstein number (Bo) revealed that the degrees of plug-flow deviation and backmixing are negatively correlated with the molecular weight distribution.

Polyether-Thiourea-Siloxane Copolymer Based on H-Bonding Interaction for Marine Antifouling.

By introducing thiourea and ether groups into MQ silicone resin polymer via free radical polymerization, a polyether-thiourea-siloxane (PTS) copolymer was synthesized. The characterization of the synthesized copolymer indicated the occurrence of H-bonding interactions and a narrow molecular weight polydispersity index. Antifouling coatings were produced by incorporating the synthesized copolymer and phenylmethylsilicone oil (PSO). The addition of a minute amount of copolymer enhanced the hydrophobicity of the coating by increasing its surface roughness. However, excessive addition of copolymer resulted in a significant deterioration of the coating surface smoothness. The copolymer improved the mechanical properties of the coating, but excessive addition decreased the crosslinking density and weakened the mechanical performance. With increasing copolymer addition, the leaching of PSO was significantly improved due to the change in the storage form of PSO in the coating caused by the copolymer. Based on the H-bonding interaction of the copolymer, the adhesion strength between the coating and the substrate was significantly improved. However, excessive addition of copolymer did not infinitely enhance the adhesion strength. The antifouling performance demonstrated that an appropriate amount of copolymer could obtain adequate PSO leaching efficiency, thereby effectively enhancing the antifouling performance of the coating. In this study, the prepared coating P12 (12 g of PTS in 100 g of PDMS) showed the most effective antifouling performance.

Synthesis of Si‐O‐Si bridged diamido Group 4 complexes and the applications to polymerization of olefins

Titanium, zirconium, and hafnium complexes O[Me2Si(Dip)N]2MCl2 [Dip = 2,6‐iPr2C6H3; M = Ti (1), Zr (2), Hf (3)], O[Me2Si(tBu)N]2ZrCl2 (4), and O[iPr2Si(Dip)N]2ZrCl2 (5) supported by Si‐O‐Si bridged diamido ligands were synthesized. X‐ray diffraction analysis disclosed that complex 2 displays a distorted trigonal bipyramidal geometry. Complexes 1–5, upon the activation with sMAO, exhibited diverse catalytic performance for the polymerization of ethylene and copolymerization of ethylene with norbornene or 1‐octene. For ethylene homopolymerization, both complexes 1–2 are good catalysts giving polymer with high molecular weight and narrow polydispersities. Complex 2 catalyzed copolymerization of ethylene with 1‐octene exhibiting high catalytic activity but with norbornene showing moderate activity, affording corresponding high molecular weight copolymers with relatively high comonomer incorporations of 11% and 29%, respectively.

Rapid Controlled Synthesis of Large Polymers by Frontal Ring-Opening Metathesis Polymerization

Tunable molecular weight and well-defined polydispersity are the hallmarks of a controlled polymerization. This process relies on vanishingly small termination rates, minimal chain transfer, and initiation rates faster than propagation rates. Ring-opening metathesis polymerization (ROMP) is a well-known controlled polymerization based on the opening of strained cyclic olefins. The exothermic nature of ROMP allows rapid conversion of neat monomers to polymers through frontal ROMP (FROMP). Unlike traditional ROMP, FROMP uses the exothermic heat from the opening of strained cyclic olefins to thermally activate the initiator that sustains the propagation of a cascading reaction front. Although the reaction mechanisms for ROMP and FROMP are the same, the reaction conditions differ greatly, especially in the temperature and monomer concentration. The ability to control the polymerization under FROMP conditions has yet to be investigated, as well as its potential in the synthesis of well-defined polymers without the use of solvents and with minimal energy input. Here, we show that FROMP rapidly transforms monomers into polymers of high-molecular weight (Mn) with good fidelity and low dispersity (Đ). Specifically, the synthesis of polymers with Mn up to 700 kg/mol and Đ of 1.5 was achieved with a rapid, solvent-free, and oxygen-tolerant frontal polymerization technique. Further control of the polymerization was possible with the addition of a phosphite ligand that lowered the Đ to 1.2. We anticipate that controlled FROMP will become a valuable macromolecular synthetic tool due to its reliability, speed, scalability, and simplicity.

Confinement-Induced Fractionation and Liquid-Liquid Phase Separation of Polymer Mixtures.

The formation of (bio)molecular condensates via liquid-liquid phase separation in cells has received increasing attention, as these aggregates play important functional and regulatory roles within biological systems. However, the majority of studies focused on the behavior of pure systems in bulk solutions, thus neglecting confinement effects and the interplay between the numerous molecules present in cells. To better understand the physical mechanisms driving condensation in cellular environments, we perform molecular simulations of binary polymer mixtures in spherical droplets, considering both monodisperse and polydisperse molecular weight distributions for the longer polymer species. We find that confinement induces a spatial separation of the polymers by length, with the longer ones moving to the droplet center. This partitioning causes a distinct increase in the local polymer concentration near the droplet center, which is more pronounced in polydisperse systems. Consequently, the confined systems exhibit liquid-liquid phase separation at average polymer concentrations where bulk systems are still in the one-phase regime.

Degradation of Alkaline Lignin in the Lactic Acid-Choline Chloride System under Mild Conditions

Lignin is a natural polymer, second only to cellulose in natural reserves. Degradation is one of the ways to achieve the high-value transformation of lignin. Deep eutectic solvent (DES) thermal degradation of lignin can be used as an excellent green degradation method. This paper introduces the degradation mechanism and effect of the lactic acid-choline chloride DES system in dissolving and degrading alkaline lignin, and the final solvent recovery. It can also be found from the scanning electron microscope (SEM) images that the surface of the degraded solid product is transformed from smooth to disordered. Fourier transform infrared (FTIR) spectroscopy and 1 H-NMR spectroscopy were used to characterize the changes in lignin functional groups during DES treatment. The results showed that the content of phenolic hydroxyl groups increased after degradation, indicating that the β-O-4 ether bond was broken. The molecular weight of the degraded lignin was observed by gel permeation chromatography (GPC), and the lignin residue with low molecular weight and narrow polydispersity index was obtained. The lowest average molecular weight (Mw) reached 2512 g/mol. The ratio of oxygen to carbon atoms in lignin increased substantially during degradation as measured by X-ray photoelectron spectroscopy (XPS), probably because DES treatment was accompanied by many oxidation reactions, which led to significant structural changes in lignin and a large number of ether bond breakage reactions during the reaction. The main final degradation products are aromatic monomers, vanillin, butyrovanillone, etc.

Living ring-opening polymerization of β-butyrolactone initiated by mononuclear zirconium compounds containing sterically hindered N,O-chelate and anionic dimethylamide ligands.

The ring-opening polymerization of β-lactones into polyhydroxyalkanoates (PHA), biodegradable polymers with high molecular weight and narrow polydispersity, is of significant interest. The mononuclear zirconium compound containing sterically hindered N,O-chelate and anionic dimethylamide ligands was used as an initiator for the polymerization of β-butyrolactone (BBL), resulting in polyhydroxylbutyrate (PHB) with a number-average molecular weight of 12 000 g mol-1. Kinetic studies demonstrate a first-order dependence on β-butyrolactone (BBL) concentration at room temperature, accompanied by narrow molecular weight distributions (ca. 1.03-1.07), indicating a well-controlled living polymerization.

Mechanically Driven Atom Transfer Radical Polymerization by Piezoelectricity.

Targeting sustainable and eco-friendly polymer synthesis, we demonstrate here a synergistically catalyzed atom transfer radical polymerization (ATRP) induced and controlled by interplay between ball milling (BM) and piezoelectric nanoparticles (piezoNPs). BM-induced electron transfer can be achieved through piezoNPs deformation under impact force, serving as an external stimulus to mediate polymerization. The ppm level of copper loading is sufficient in fabrication of a polymer with well-defined molecular weight and low polydispersity. High-molecular-weight polymers ranging from 33 to 74 kDa were prepared successfully through DMSO-assisted grinding. Besides, its good performance on availability of water as liquid-assisted grinding additive, the recyclability of piezoNPs, and the formation of cross-linker-free composite resin make our ATRP approach a green and practical option alongside the existent heat-, electro-, and photo-induced methods.

Structure–property relationship in the evaluation of xanthan gum functionality for oral suspensions and tablets

The functional properties of xanthan gum (XG) in pharmaceutical preparations depend on its rheological properties, which inevitably rely on its molecular structure. Hence, this work investigated the relationship between the molecular structure of XG and its rheological properties and functional characteristics, and revealed the structural factors influencing the XG functionalities in oral suspensions and matrix tablets. Primarily, the molecular structures of four commercial XG products were characterized by infrared spectroscopy, differential scanning calorimetry and measuring the monosaccharide composition, average molecular weight, and pyruvate and acetyl contents. Furthermore, the flow behavior and viscoelasticity of XG solutions, the viscoelasticity of XG hydrogels, and XG combinations (XGC, aqueous solution containing XG, liquid glucose, and glycerin) were investigated. Finally, the dissolution time of XGC and the swelling and erosion properties of the XG matrix were studied to evaluate XG functionality in oral suspensions and matrix tablets, respectively. Results showed that the polydispersity of molecular weight and the pyruvate content affected the functionality and performance of XG in suspension and tablet forms. The higher polydispersity and pyruvate content of XG improved the hydrogel strength, which led to a longer dissolution time of XGC and a higher swelling extent of the XG matrix but a slower erosion rate.

Characterization of DOM Released from Bacteria in Response to Chlorine in Water Based on Indicator Bacteria E. coli

In this study, Escherichia coli (E. coli) was used as an indicator bacterium treated with five different concentrations of chlorine (0.1; 0.5; 1.0; 2.0, and 5.0 mg/L) and without chlorine (0.0 mg/L) to evaluate the changes in the DOM characteristics. The dissolved organic carbon (DOC) concentration initially increased along with the chlorine concentrations and decreased after 24 hours (0.0 and 0.1 mg/L) and 168 hours (0.5; 1.0; 2.0 and 5.0 mg/L). Ultra-violet absorbance at 260 nm (UV260) showed that the absorbance decreased for control without chlorine (0.0 mg/L) and 0.1 mg/L chlorine, while increased for other concentrations of chlorine within 120 hours. The DOC and UV260 results indicated that the high concentrations of chlorine initiated high contents of DOM which contained more humic-like molecules than the DOM released from E. coli without chlorine. Fluorescence excitation-emission matrix (EEM) analysis suggested that the DOM released from E. coli without chlorine enriched with protein-like substances, whereas the fulvic-like and humic-like substances more intensified in the DOM for the high concentrations of chlorine (>1.0 mg/L). The molecular weight distribution of DOM showed that the intensity of high molecular weight substances and polydispersity increased along with chlorine concentration and contact time, whereas the low molecular weight substances were relatively higher in the DOM for control without chlorine. The obtained results of this study would be useful for a better understanding of the variation of DOM during treatment and could be used as an important reference for optimizing the operation condition of the water treatment plants.

Subcritical Water as a Pre-Treatment of Mixed Microbial Biomass for the Extraction of Polyhydroxyalkanoates.

Polyhydroxyalkanoate (PHA) recovery from microbial cells relies on either solvent extraction (usually using halogenated solvents) and/or digestion of the non-PHA cell mass (NPCM) by the action of chemicals (e.g., hypochlorite) that raise environmental and health hazards. A greener alternative for PHA recovery, subcritical water (SBW), was evaluated as a method for the dissolution of the NPCM of a mixed microbial culture (MMC) biomass. A temperature of 150 °C was found as a compromise to reach NPCM solubilization while mostly preventing the degradation of the biopolymer during the procedure. Such conditions yielded a polymer with a purity of 77%. PHA purity was further improved by combining the SBW treatment with hypochlorite digestion, in which a significantly lower hypochlorite concentration (0.1%, v/v) was sufficient to achieve an overall polymer purity of 80%. During the procedure, the biopolymer suffered some depolymerization, as evidenced by the lower molecular weight (Mw) and higher polydispersity of the extracted samples. Although such changes in the biopolymer’s molecular mass distribution impact its mechanical properties, impairing its utilization in most conventional plastic uses, the obtained PHA can find use in several applications, for example as additives or for the preparation of graft or block co-polymers, in which low-Mw oligomers are sought.