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Because of its acidic and oxidative nature, iron gall ink promotes the endogenous degradation of paper manuscripts. Mechanical damage in areas of concentrated ink application or along mechanically stressed edges or folds results in problems during storage and handling. So far, such strongly degraded areas have usually been stabilized locally with thin Japanese paper and adhesives. A new and innovative material—nanocellulose—is being evaluated as a stabilizer for manuscripts that have been degraded by iron gall ink. The aim of this study is to integrate the nanocellulose application into a multi-stage calcium phytate/calcium hydrogencarbonate treatment to combine deacidification and stabilization, thus avoiding an additional stabilization and drying step. Two different types of fibrillated nanocelluloses were applied on manuscripts damaged by iron gall inks in different treatment steps. The newly formed, interlinked network of nanocellulose and paper was characterised before and after accelerated degradation in closed vials. The effects on the paper cellulose were studied by size exclusion chromatography and light scattering with carbonyl group profiling to follow cellulose hydrolysis and oxidation pathways. In addition, the migration behavior of iron ions was examined by laser ablation coupled with metal analysis (ICP-MS). This paper discusses the applicability and stability of nanocellulose on paper damaged by iron gall ink with regard to its long-term performance. Advantages and limitations are covered in detail.

Two extracellular alkalistable 1,4-β- d -glucan-4-glucanohydrolase (EC 3.2.1.4) fractions, namely Endo A and Endo B were separated from the culture filtrate of an alkalotolerant Fusarium strain by gel chromatography on Bio Gel P-100 column. The viscometric characterization of enzyme indicated that the Endo B was 1.9 times more random in action as compared to Endo A. Both the endoglucanases showed comparable patterns of their ability to release short fibers in the reaction mixture when filter paper was used as the substrate. The average size of released short fibers was determined by scanning electron microscopy ranged between 20 and 100 μm. Adsorption characteristics of the endoglucanases indicated that the enzyme complex acts prominently at the surface of substrate rather than at their cracked edges. The X-ray diffractograms showed that the crystallinity of the substrates does not vary significantly in the initial stages of the enzymatic action. The extracellular enzyme preparation was found to be suitable for deinking of mixed office waste papers. The enzyme treatment resulted in the increase in brightness with the reduction in ink counts of the recycled paper. Based on the distinct properties of endoglucanases a probable mechanism of enzymatic deinking process is presented schematically.

In this work, a novel polymeric fluorescent brightener agent based on 4,4′-diamino-stilbene-2,2′-disulfonic acid-triazine structure has been synthesized by radical polymerization. The structure of 4,4′-diamino-stilbene-2,2′-disulfonic acid -based polymeric fluorescent brightener agent was characterized by Fourier-transform-infrared spectroscopy, 1HNMR, and gel permeation chromatography. Photo-property was measured and analyzed by the ultraviolet–vis spectra and fluorescence spectra. The performance on paper was evaluated by determining the surface strength and smoothness, the brightness degree, and the post color number value of paper. Results showed that 4,4′-diamino-stilbene-2,2′-disulfonic acid-based polymeric fluorescent brightener agent had a better light stability in water solution than that of 4,4′-diamino-stilbene-2,2′-disulfonic acid-based fluorescent monomer as light stabilizer. Through the surface-sizing experiment and ultraviolet aging experiment, the 4,4′-diamino-stilbene-2,2′-disulfonic acid-based polymeric fluorescent brightener agent not only enhanced the surface strength and smoothness of paper as a surface-sizing agent, but also had a better effect on anti-ultraviolet aging than that of 4,4′-diamino-stilbene-2,2′-disulfonic acid-based fluorescent monomer as a light stabilizer and fluorescent brightener agent.

Fifty actinomycete strains isolated from lignocellulosic substrates were examined for the ability to remove the color from a paper mill effluent obtained after semichemical alkaline pulping of wheat straw. Streptomyces sp. strains UAH 15, UAH 23, UAH 30, and UAH 51 were selected for their ability to decolorize the effluent in a liquid medium containing 1% (wt/vol) glycerol, 0.2% (wt/vol) ammonium sulfate, and 80% (vol/vol) effluent. The highest levels of decolorization achieved after the strains grew were 60 to 65%. Strains UAH 30 and UAH 51 were selected for further study because of their different patterns of effluent decolorization during growth. Fractionation of the decolorized effluent by gel permeation chromatography demonstrated that there were reductions in the levels of absorbance of the high- and medium-molecular-weight compounds. These fractions were mainly responsible for the color of the effluent, while the last fractions, the low-molecular-weight compounds, could have been responsible for the residual color of the decolorized effluent. Thin-layer chromatography revealed significant differences among the patterns of bands corresponding to the acidified supernatants obtained after precipitation of alkali-lignin from the effluent samples decolorized by different Streptomyces strains.

A method has been developed for the analysis of chlorinated dioxins and furans in paper products at the pg/g level. The procedure involves Soxhlet extraction of the paper with ethanol, gel permeation chromatography, sulphuric acid treatment, and Florisil and Carbopack chromatography. The paper extracts are analysed by capillary column gas chromatography/high resolution mass spectrometry. Preliminary analyses indicate the presence of chlorinated dioxins and furans in most paper products tested.

Herein, we report an iron(II)‐catalyzed polymerization of arylallenes. This reaction proceeds rapidly at room temperature in the presence of a hydride co‐catalyst to generate polymers of weight up to M n=189 000 Da. We have determined the polymer structure and chain length for a range of monomers through a combination of NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. Mechanistically, we postulate that the co‐catalyst does not react to form an iron(II) hydride in situ, but instead the chain growth is proceeding via a reactive Fe(III) species. We have also performed kinetic and isotopic experiments to further our understanding. The formation of a highly unusual 1,3‐substituted cyclobutane side‐product is also investigated., A rare example of transition metal‐catalyzed polymerization of aryl allenes is presented. Reactions are mild and generate very high M n polymers with narrow polydispersity by using a well‐defined Fe(II) pre‐catalyst and a hydride additive. [2+2] cycloaddition to form cyclobutanes is also viable using the same catalytic system.

Here, we investigate the recovery and reuse of polyvinylidene fluoride (PVDF) binders from both homemade and commercial cathode films in Li ion batteries. We find that PVDF solubility depends on whether the polymer is an isolated powder or cast into a composite film. A mixture of tetrahydrofuran:N‐methyl‐2‐pyrrolidone (THF : NMP, 50 : 50 v/v) at 90 °C delaminates composite cathodes from Al current collectors and yields pure PVDF as characterized by 1H nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), wide‐angle X‐ray scattering (WAXS), and scanning electron microscopy (SEM). PVDF recovered from Li ion cells post‐cycling exhibits similar performance to pristine PVDF. These data suggest that PVDF can be extracted and reused during Li ion battery recycling while simultaneously eliminating the formation of HF etchants, providing an incentive for use in direct cathode recycling., The structure, purity, and reuse of polyvinylidene fluoride binder recovered from spent lithium‐ion battery cathodes have been investigated.

The electron beam irradiation (EBI) of native lignin has received little attention. Thus, its potential use in lignin-based biorefineries is not fully understood. EBI was applied to selected lignin samples and the structural and chemical changes were analyzed, revealing the suitability, limitations, and potential purpose of EBI in wood biorefineries. Isolated milled wood, kraft, and sulfite lignin from beech and eucalyptus were subjected to up to 200 kGy of irradiation. The analysis included gel permeation chromatography for molar masses, heteronuclear single quantum coherence (HSQC)- and 31P NMR and headspace gas chromatography-mass spectrometry for functional groups, and thermogravimetric analysis for thermal stability. Most samples resisted irradiation. Subtle changes occurred in the molecular weight distribution and thermal stability of milled wood lignin. EBI was found to be a suitable pretreatment method for woody biomass if the avoidance of lignin condensation and chemical modification is a high priority.

End‐functionalized hydrogenated polymers obtained from nitrile‐butadiene rubber (NBR) yield new materials with suitable properties for a number of applications as sealing material and adhesives. We investigated the one‐step synthesis of ester end‐functionalized hydrogenated nitrile‐butadiene rubber (EF‐HNBR) by combining the functional metathesis with the hydrogenation of NBR in the presence of the 2nd generation Grubbs catalyst and a functionalized olefin as a chain transfer agent (CTA). We established the operating conditions for the effective production of saturated functional polymers with a high degree of hydrogenation, high chemo‐selectivity and moderate molecular weight. The structures of the products were confirmed by FT‐IR and 1H‐NMR spectroscopy, rubber molecular weight, and distribution determined by using gel permeation chromatography (GPC); their thermal properties were determined by thermo‐gravimetric analysis (TGA) and different scanning calorimetry (DSC)., The one‐step synthesis of high degree of hydrogenation and designated structure ester end‐functionalized hydrogenated nitrile‐butadiene rubber (EF‐HNBR) was successfully explored via combining the functional metathesis with the hydrogenation of NBR in presence of the 2nd generation Grubbs catalyst and a functionalized olefin as a chain transfer agent (CTA). Our results pave a new way for the precise synthesis of the end‐functionalized saturated polymers in one single step.

Modification of lignin with poly(e-caprolactone) is a promising approach to valorize industrial low-value lignins and to advance the bioeconomy. We have synthesized lignin grafted poly(e-caprolactone) (lignin-g-PCL) copolymers via ring-opening polymerization of e-caprolactone with different types of lignins of varying botanical sources (G-type pine lignin, S/G-type poplar lignin, and C-type Vanilla seeds lignin) and lignin extraction methods (Kraft and ethanol organosolv pulping). The lignin-g-PCL copolymer showed remarkably improved compatibility and dispersion in acetone, chloroform, and toluene in comparison to non-modified lignins. The structure and thermal properties of the lignin-g-PCL were investigated using Fourier-transform infrared spectroscopy (FTIR), 31P nuclear magnetic resonance (NMR), 2D heteronuclear single quantum correlation (HSQC) NMR, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). We have found that all the technical lignins were reactive to the copolymerization reaction regardless of their plant source and isolation methods. The molecular weights of the synthesized lignin-g-PCL copolymers were positively correlated with the content of aliphatic lignin hydroxyls, suggesting that the copolymerization reaction tends to occur preferentially at the aliphatic hydroxyls rather than the phenolic hydroxyls of lignin. Thermal analyses of the lignin-g-PCL copolymers were studied, and in general, a reduction of melting temperature and crystallinity percentage in comparison to the neat PCL was observed. However, the thermal behavior of lignin-g-PCL copolymers varied depending on the lignin feedstocks employed in the copolymerization reaction.

The health of key species in the Baltic region has been impaired by exposure to anthropogenic hazardous substances (AHSs), which accumulate in organisms and are transferred through food chains. There is, thus, a need for comprehensive characterization of the occurrence and accumulation of AHSs in the ecosystem. In this study, we use a non-target screening (NTS) approach for this purpose. A major challenge in NTS of biological samples is the removal of matrix components such as lipids that may interfere with the detection and identification of compounds of interest. Here, we combine gel permeation chromatography with Florisil® column fractionation to achieve sufficient lipid removal for gas chromatography–high-resolution mass spectrometry analysis using electron ionization (EI) and electron capture negative ion chemical ionization (ECNI). In addition, we present new data processing workflows designed to systematically find and identify frequently occurring and biomagnifying AHSs, including known, emerging, and new contaminants. Using these workflows, we discovered a wide range of contaminants in tissue samples from blue mussels, fish, and marine mammals, and calculated their biomagnification factors (BMFs). Compounds with BMFs above 1 for herring and at least one marine mammal included legacy chlorinated pollutants (polychlorinated biphenyls, DDTs, chloro-benzenes/cyclohexanes, chlordanes, toxaphenes, dieldrin), polybrominated diphenyl ethers (PBDEs), and brominated biphenyls. However, there were also several halogenated natural products (halogenated methoxylated brominated diphenyl ethers, 1′-methyl-1,2′-bipyrroles, 1,1′-dimethyl-2,2′-bipyrroles, and the halogenated monoterpene mixed halogenated compound 1) as well as the novel flame retardant Dechlorane 602 and several polycyclic aromatic hydrocarbons, terpenoids, and steroids. The legacy pollutants exhibited the expected biomagnification behavior, demonstrating the utility of the unguided data processing workflow. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s00216-020-03018-4.

The aim of this work was to investigate the possibility of processing forest residues by chemical delignification preceded by mild steam explosion. The focus was on using soda pulping, due to its simplicity. Kraft cooking was used for comparison to improve the understanding of the separation of the complex yet promising resource. The raw material consisted of chipped branches, bark, and twigs of mixed hardwood and softwood. Analysis of the raw material proved to be challenging due to the presence of a substantial fraction of extractives. Analysis of the pulps showed that the forest residue delignification was faster than that of wood. The effects of steam explosion were evaluated with the help of composition analysis, gel permeation chromatography (GPC) for the molecular weight of lignin, and NMR for the changes in its structure. The impact of steam explosion was found to be limited, possibly due to the relatively small size of the material.

This study investigates the feasibility of acid precipitation for the separation and recovery of lignin and hydrocarbon derivatives from the waste stream of the alkali extraction of recycled cardboard. The recovery of chemicals from this effluent is complex due to their heterogeneity. Apart from the lignin and hydrocarbon derivatives, also, fillers, inks, and polysaccharides are present. A procedure of fractional acid precipitation was designed, reducing the pH from 10.7 to 8.8, 7.2, 5.1, 3.1, and 1.5. Each solid fraction was analyzed by infrared spectroscopy to determine its chemical composition and amount of precipitate. A mixture of lignin and hydrocarbon derivatives was detected in the solids obtained at pH 3.1. A dichloromethane extraction of the hydrocarbon derivatives was performed. Both recovered lignin and hydrocarbon were analyzed by infrared and gel permeation chromatography. The lignin showed similar characteristics (e.g., molecular weight ≈ 10.000 Da) as commercial lignin from virgin softwood. For the hydrocarbon derivatives, a molecular weight range between 10,000 and 150 Da was observed. In conclusion, this paper shows that the recovery of lignin and hydrocarbon derivatives is scientifically and technologically possible from thewaste stream of the cardboard recycling processes. Further research is necessary to improve the extraction efficiency that was around 7.9% for the lignin and around 5.5% of the total amount of extractives compared with their amount in cardboard. Despite the low extraction efficiency, the estimated 9.6 million tons of lignin present in cardboard and the lignin price around 300–500 USD/ton make this research of industrial interest.

International audience; A high-throughput agarose gel electrophoresis (AGE) analytical method has been developed to separate lignin fractions according to their molecular weight (M w), charge, and shape. Operating conditions to effect separation of species have been evaluated along with imaging parameters. Kraft, soda (Protobind), and Organosolv lignins showed distinct differences in migration. Bands were cut, extracted, and cross-analyzed by gel permeation chromatography (GPC), 1 H NMR, and pyrolysis GC/MS to confirm their identity as lignin. The band intensity was correlated with lignin concentration by running serially diluted samples and imaging each lane to produce a precise calibration curve. The AGE technique was used to monitor and compare enzymatic, bacterial, chemical, and hydrothermal lignin digestions. Each method showed changes in lignin migration and band intensities over time. Low M w species were seen in samples collected from the anode buffer tank. Though requiring further development, the AGE method can provide structural information about the lignin and is accessible to biological and chemistry laboratories.

Biomass utilization, even for conversion products like hydrochar or biochar, has an increasing demand because improper disposal can cause intensive pollution. In this study, hydrochar obtained by hydrothermal treatment of corn stalk was added to virgin asphalt as a novel modifier by manual stirring and high-speed shearing. This hydrochar-modified asphalt (HCMA) showed a better high-temperature performance compared to unmodified asphalt, and the optimized dosage was 6 wt% with Rutting Index reaching 76 °C, and its penetration and softening point reaching 31.70 (0.1 mm) and 54.70 °C, respectively. The macroscopic representation of modified asphalt was conducted by microscopic characterization methods such as Fourier Transform Infrared Spectroscopy (FTIR) and Gel Permeation Chromatography (GPC). It was demonstrated that the performance was improved by the good blending state between hydrochar and asphalt. The application of hydrochar in modifying asphalt can reduce pollution and enhance its high-temperature performance, which has a potentially extensive application prospect in pavement engineering in subtropical and tropical climate.

An active recombinant human pancreatic lipase (recHPL) was successfully prepared for the first time from the Escherichia coli expression system using short Strep-tag II (ST II). The recHPL–ST II was solubilized using 8 M urea from E.coli lysate and purified on a Strep-Tactin-Sepharose column. After refolding by stepwise dialyses in the presence of glycerol and Ca2+ for 2 days followed by gel filtration, 1.8–6 mg of active recHPL–ST II was obtained from 1 L of culture. The recHPL was non-glycosylated, but showed almost equal specific activity, pH-dependency and time-dependent stability compared to those of native porcine pancreatic lipase (PPL) at 37°C. However, the recHPL lost its lipolytic activity above 50°C, showing a lower heat-stability than that of native PPL, which retained half its activity at this temperature.

In this work we demonstrate the use of Co(acac)3 in combination with N-hydroxyphthalimide as an oxidant for the selective α-oxidation of the representative β-O-4 linkages in lignin model compounds. The oxidation reaction proceeds under mild conditions at 80 °C using 1,4-dioxane as the solvent and an oxygen atmosphere. The prior α-oxidation in the β-O-4 linkage of the lignin polymer is known to result in an easier cleavage of the adjacent C–O and C–C bonds because of a decrease in bond stability. Finally, the conditions were successfully transferred to kraft- and organosolv-lignin samples as proven by 2D-NMR (HSQC) experiments and gel permeation chromatography measurements.

Tannins are soluble, astringent secondary phenolic metabolites generally obtained from renewable natural resources, and can be found in many plant parts, such as fruits, stems, leaves, seeds, roots, buds, and tree barks, where they have a protective function against bacterial, fungal, and insect attacks. In general, tannins can be extracted using hot water or organic solvents from the bark, leaves, and stems of plants. Industrially, tannins are applied to produce adhesives, wood coatings, and other applications in the wood and polymer industries. In addition, tannins can also be used as a renewable and environmentally friendly material to manufacture bio-based polyurethanes (bio-PUs) to reduce or eliminate the toxicity of isocyanates used in their manufacture. Tannin-based bio-PUs can improve the mechanical and thermal properties of polymers used in the automotive, wood, and construction industries. The various uses of tannins need to be put into perspective with regards to possible further advances and future potential for value-added applications. Tannins are employed in a wide range of industrial applications, including the production of leather and wood adhesives, accounting for almost 90% of the global commercial tannin output. The shortage of natural resources, as well as the growing environmental concerns related to the reduction of harmful emissions of formaldehyde or isocyanates used in the production of polyurethanes, have driven the industrial and academic interest towards the development of tannin-based bio-PUs as sustainable alternative materials with satisfactory characteristics. The aim of the present review is to comprehensively summarize the current state of research in the field of development, characterization, and application of tannin-derived, bio-based polyurethane resins. The successful synthesis process of the tannin-based bio-PUs was characterized by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), MALDI-TOF mass spectrometry, and gel permeation chromatography (GPC) analyses.

Thermoresponsive star polymers are synthesized by using poly(NIPAM‐b‐DMA) diblock copolymer and β‐cyclodextrin (β‐CD). The synthesis of thermoresponsive diblock copolymer (TRP) is carried out by reversible addition–fragmentation chain transfer mediated aqueous polymerization using N‐isopropylacrylamide (PNIPAM) and di‐methylacrylamide as monomers. Mercaptopropionic acid is used as in situ chain transfer agent (CTA) to synthesize PNIPAM, i.e., macro‐CTA. The polymeric materials are characterized by Fourier‐transform infrared spectroscopy, gel permeation chromatography, 1H‐NMR, particle size measurement, scanning electron microscopy, thermogravimetric analysis, UV–vis spectroscopy, and X‐ray diffraction analysis. PNIPAM, TRP, and b‐CD grafted thermoresponsive diblock copolymer (β‐CD‐TRP) show lower critical solution temperature at 32.8, 34.3, and 36.8 °C, respectively. TRP and β‐CD‐TRP are also studied for the removal of model contaminant (kaolin). Among all grades, β‐CD‐TRP 4 shows the best performance in the removal of kaolin from aqueous solution at 25 and 50 °C., The enhanced flocculation performance of thermoresponsive diblock copolymer (TRP) and b‐CD grafted thermoresponsive diblock copolymer b‐CD‐TRP is demonstrated below and above lower critical solution temperature (LCST) in kaolin suspension at neutral pH.

The effluent of a pulp mill was subjected to a biological treatment followed by ozonation to study the potential biodegradability improvement of recalcitrant compounds. Characteristics of the bio-treated pulp wastewater (BTPW) before and after the ozonation process were analysed by Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, gel permeation chromatography, and gas chromatography, which detected the variations in the organic compounds in the effluents. Results showed that the ozonation treatment has the potential to turn some refractory compounds into biodegradable compounds and therefore increase the biodegradability of the BTPW. The increased biodegradability was accomplished because ozonation affects the structure of the refractory compounds and degrades the macromolecular organic matter into micromolecular organic matter. Furthermore, it is proposed that the degradation of macromolecular organic matter happens fast and therefore there are structural changes, since smaller molecules are formed. Then, these smaller molecules degrade over a longer period.

To investigate the wide range of pollutants occurring in sewage sludge, an analytical method for comprehensive non-target screening is needed. To the best of our knowledge, no procedures currently exist for the full screening of organic contaminants in sewage sludge, which is the ultimate goal of this project. We developed non-discriminating sample preparation methods for gas chromatography-mass spectrometry (GC-MS) analysis. Pressurized liquid extraction (PLE) was used for extraction, with in-line (silica gel selective PLE, SPLE) or off-line clean-up (gel permeation chromatography, GPC). This combination allowed the analysis of non-polar compounds of all sizes and small semi-polar and non-polar compounds. The results show that the combination of SPLE and PLE with GPC is suitable for analysis of established as well as new contaminants. Both methods were validated for 99 compounds with different properties. For all GC suitable analytes, either one of the methods produced acceptable recoveries (64 to 136%). As a test, the two methods were used for non-target screening of Swedish sewage sludge. A tiered approach was used to tentatively identify the sludge contaminants. In total, 1865 and 1593 compounds were found of which 321 and 192 compounds were tentatively identified for the PLE and SPLE method, respectively. For a comprehensive coverage of contaminants, the two methods should be used together, with the PLE method covering a wider polarity range and the SPLE method a wider size range. In addition, polar substances will require liquid chromatography-mass spectrometry analysis, the method for which will be developed soon. Electronic supplementary material The online version of this article (doi:10.1007/s00216-017-0429-0) contains supplementary material, which is available to authorized users.

Ash-flushing wastewater generated by coal fired power plant generally contains high massive suspended coal fly ashes, which limit the recycling of ash-flushing wastewater and contaminate the environment due to the release of heavy metals from coal fly ashes. In this study, the Biopolymeric Flocculant extracted from Potato Residues (BFPR) under alkaline condition was applied to treat ash-flushing wastewater. The extraction conditions were optimized. The results showed that the highest yield of 58.77% BFPR was extracted from potato residues under the optimum condition: temperature 100 °C, potato residue concentration 42.09 g/L, extraction time 25.27 min, NaOH concentration 0.48 M and MgSO4•7H2O concentration 0.4 g/L. Gel permeation chromatography analysis indicated that the approximate molecular weight (MW) of BFPR was 4781 kDa. Fourier transform infrared spectroscopy indicated the presence of carboxyl, hydroxyl, and methoxyl groups in BFPR. Furthermore, BFPR showed good flocculating efficiency of 93.44% to ash-flushing wastewater when 8.3 mg/L BFPR was added, and thus achieved the recycling of ash-flushing wastewater.

Lumbar fusion surgery has grown in popularity as a solution to lower back pain. Surgical site infection (SSI) is a serious complication of spinal surgery, affecting as high as 8.5% of the patient population. If the SSI cannot be eradicated with intravenous antibiotics, the next step is second surgery, which increases the cost imposed on the patient and extends recovery time. An implantable ultrasound-triggered polyether ether ketone device for the dispersal of antibiotics has been developed as a potential solution. In this study, the device was constructed of bioabsorbable medical grade polymer, enabling gradual degradation, and manufactured via fused filament fabrication (FFF). A novel bioabsorbable filament was manufactured and validated with gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The filament was consistent in molecular weight and thermal properties (p = 0.348 and p = 0.487, respectively). The filament was utilized for FFF of the device. Dimensional accuracy of the device was assessed with μCT analysis. Dimensional differences between the printed device and intended design were minimal. Degradation of raw material, filament, and the device was performed in accordance to ASTM F1635-16 for a month to determine how melting the material impacted the degradation properties. The degradation rate was found to be similar among the samples weeks one through three however, the raw material degraded at a slower rate by the final week (p = 0.039). This study demonstrated the feasibility of utilizing medical grade bioabsorbable polymers in FFF.

The increasing production of toxic sludge becomes the limiting factor of sludge resource utilization. In this study, the source of sludge toxicity and the best way for toxic organic reduction was investigated. Four disintegration methods (freeze/thaw, ultrasonication, alkali-thermal hydrolysis and ozonation) were used to analyze the release of organic matter and sludge toxicity reduction. Ultrasonication (SCOD = 5120.4 ± 67.8 mg L−1) was the best way to break sludge and remove toxicity among four methods, which dissolution rate was more than 80%, and the total toxicity inhibition rate could be reduced to 64.3 ± 4.2%, significantly reducing the toxicity of sludge. Gel chromatography (GPC) showed that the disintegration could convert refractory macromolecular organics (MW > 10 kDa) into small molecular substances (MW

In the conventional pulp and papermaking process, lignin in black liquor is mostly burned for energy. It has not been widely used as a functional polymer. To use both cellulose and lignin component, unique kraft cooking conditions were used in bamboo cooking in this study, and acid precipitation was used to extract lignin from the black liquor. Under different pH values, the precipitated lignins were characterized and compared by gel permeation chromatography (GPC), dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR). Lignin dissolution in acidic conditions was studied. Pulps with high lignin content were used to synthesize oil absorption materials, which were prepared by grafting butyl methacrylate (BMA) onto the cellulose chain. Sodium silicate was used as an initiator, and 1,4-butane dioldimethacrylate (BDDMA) was used as a crosslinker. The structures of grafted copolymers were characterized by FTIR, scanning electron microscopy (SEM), and thermogravimetry (TG). The acid precipitation process was found to be effective and has important implications for the further lignin applications. The grafting reaction between pulps and BMA was successful. The silicone oil absorption capacity of the obtained materials was 15.3 g/g.

A new polysaccharide (MEP-1) was isolated from fruit body of wide Morchella esculenta (L.) Pers with a stepwise procedure of hot water extraction, removal of the protein, dialysis against water, DEAE-Cellulose A52 and Sephadex G-100 columns. Physicochemical properties of the polysaccharide was determined by chemical methods, high-performance gel permeation chromatography, high performance liquid chromatography, paper chromatography, ultraviolet spectrum, and infrared spectrometry. The polysaccharides were primarily polymers of glucose, mannose, galactose, and arabinose. The average molecular mass was 43625 Da.

Lignin, the second most abundant natural polymer, has emerged as a potential alternative material to petroleum-based chemicals and renewable resource for the production of diverse forms of aromatics, biofuels, and bio-based materials. Thus, it is becoming important to understand its structure and properties to provide key features and insights for better/efficient lignin valorisation. In this work, the physicochemical characterisation of two types of industrial (technical) lignins, namely LignoBoost lignin and alkali-treated lignin was performed. Characterisation has been conducted using Brunauer–Emmett–Teller N2 adsorption, particle size distribution, Fourier transform infrared spectroscopy, ultraviolet–visible absorption spectroscopy, gel permeation chromatography, and thermogravimetric analysis. It was found that the pretreatment severity considerably influenced the lignin composition and functional properties. The measured physicochemical properties helped in proposing potential valorisation routes for these lignins in the context of a biorefinery, focusing on their depolymerisation and subsequent biological conversion to value-added chemicals and fuels.

An enzymatic mild acidic hydrolysis was used to separate and purify residual lignin from alkaline peroxide mechanical pulp (APMP). Using the optimum conditions for the laccase treatment (pH 4.5, temperature 50 °C, lignin consistency of 1%, a reaction time of 60 min, and a laccase dosage of 8 μ/g), oven-dried lignin was treated with laccase and in a laccase mediator system (LMS) to explore the mechanism for laccase and the LMS modification of APMP. The changes of functional groups in lignin were analyzed using nuclear magnetic resonance (31P-NMR and 13C-NMR). The molecular weight distributions of the lignin samples were confirmed by gel permeation chromatography (GPC). The 31P-NMR and 13C-NMR spectra revealed that the lignin structure changed significantly with the laccase and the LMS treatments. Meanwhile, GPC demonstrated that laccase without a mediator could lead to the polymerization of lignin, while the LMS could degrade the lignin. Hence, it was concluded that laccase is an attractive enzyme for lignin modification.