Lignin Graft Research Articles

Strong and ultrafast stimulus-healable lignin-based composite elastomers with excellent adhesion properties

With the increased environmental issues, advanced high-performance and multifunctional polymeric materials derived from biomass have tremendous attention due to the great potential to replace their traditional petroleum-based counterparts. In this work, a series of lignin graft copolymers, lignin-graft-poly(n-butyl acrylate-co-acrylic acid) (Lig-g-P(BA-co-AA)), were rationally prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization. These lignin-based copolymers demonstrate good thermal stability and tunable glass transition temperature (Tg) values. The mechanical performance, including tensile strength, extensibility, Young's modulus, and toughness can be facilely adjusted by the BA/AA feed ratio and lignin content during polymerization. Owing to the extraordinary photothermal conversion ability of lignin, the Lig-B550 copolymer, containing 11.8 wt% lignin content, shows excellent stimulus-healing behavior within 1 min with a 97.1 % healing efficiency under near-infrared (NIR) laser irradiation. Moreover, the Lig-g-P(BA-co-AA) copolymers exhibit remarkable adhesion property, broadening their potential applications in the adhesive area. This grafting strategy is versatile and efficient, conferring the resultant lignin-based composite elastomers with dramatically enhanced mechanical properties and unprecedented photothermal behavior, which can inspire the further development of strong lignin-based sustainable elastomers.

Grafting Polymerization of Long-Chain Hydrophobic Acrylic Monomer onto Lignin and Its Application in Poly(Lactic Acid)-Based Wholly Green UV Barrier Composite Films.

The development of low-cost and high-performance bio-based composites derived from forestry waste lignin and polylactic acid has emerged as a topic of central attention. However, the weak compatibility between lignin and polylactic acid often resulted in high brittleness of the composites. Graft copolymerization is not only the most effective way to modify lignin but also can significantly improve the compatibility of lignin and polylactic acid. In this study, bio-based monomer lauryl methacrylate was grafted onto lignin by feasible radical polymerization to prepare lignin graft copolymers with excellent thermal stability and hydrophobicity, which are expected to improve the compatibility with polylactic acid. Wholly bio-based composites were prepared by compounding this graft copolymer with polylactic acid. The results showed that the crystallization ability of the composite was improved, and the highest crystallinity was increased from 6.42% to 17.46%. With addition of LG-g-PLMA lower than 9%, the thermal stability of the composites was slightly improved. At 5% copolymer addition, the elongation at break and tensile toughness of the composites increased by 42% and 36%, respectively. Observation of the frozen fracture surface of the composite by SEM found that wire drawing and ductile deformation appeared when a small amount of LG-g-PLMA was added. The thus prepared composites also showed excellent UV barrier properties. This approach provides a new idea for the high-value application of lignin.

Preparation of all biomass lignin-based thermoplastic elastomers by ARGET ATRP

Lignin, which acts as the matrix in plant cell walls, has versatile potential to substitute synthetic polymers. To construct all-biomass lignin-based copolymers, lauryl methacrylate (LMA) from plant oil and isobornyl methacrylate (IBOMA) from pine sap were utilized to compose side chains on the lignin macro-initiator (OL-Br) via ARGET ATRP. A series of grafted copolymers with different molar ratios of LMA, IBOMA, and OL-Br were successfully synthesized and compared with each other through various characterization techniques. It turned out that the synthesized lignin graft copolymers have much higher molecular weights than that of linear copolymers. Besides that, the molar ratio of IBOMA/LMA in the grafted chains was positively related to the glass transition temperature of copolymer since the domain of PIBOMA is less flexible than that of PLMA. Owing to the existence of lignin, the prepared copolymer not only exhibited a good mechanical property as a typical elastomer but also showed an apparent UV absorption ability. Furthermore, a remarkable adhesive property of the copolymer had been also verified on various substrates. Therefore, it demonstrated that these obtained all-biomass lignin-based copolymers were able to partially replace synthetic elastomers and adhesives from petroleum.

Effect of lignin source and initiation conditions on graft copolymerization of lignin with acrylamide and performance of graft copolymer as additive in water- based drilling fluid

In our previous study, as effective and eco-friendly polymer additive in the water-based drilling fluids (WBDFs), lignosulfonate-g-polyacrylamide (LS-g-PAAm) graft copolymers were successfully synthesized and characterized [J. Petroleum Science and Engineering, 171(2018) 484–494]. The aim of this study was to investigate effect of the functional groups (sources) of lignin as well as initiation condition on the chemical modification of lignin via graft copolymerization method. Kraft lignin (KL) extracted from black liquor (as a waste of paper mills) and sulfonated lignin (SL) were used as lignins with the different source and chemical structure. KL and SL were then modified by graft radical copolymerization of acrylamide initiated with thermal or redox initiator. The aliphatic hydroxyl groups were identified as the active sites in the graft copolymerization, where the number of these functional groups in the lignin chain had a significant effect on the progress of the graft copolymerization reaction. Structure of the copolymers was investigated qualitatively and quantitatively using Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopies. The performance of lignin and lignin-based graft copolymers (with different grafting percentage) as an additive in the water-based drilling fluids (WBDFs) was studied. Before and after hot rolling, rheological properties including apparent viscosity, plastic viscosity, yield point as well as fluid loss were measured in the absence and presence of the salt contamination. In all fluids, except fluids containing unmodified lignin, an increase in apparent and plastic viscosities was observed. Also, thermal stability and resistance to the salt contamination were observed in fluids formulated with the graft copolymers. Best performance was observed for a fluid containing of kraft lignin graft copolymer 1 (KLGC1) where grafting percentage was as high as 452.9 wt%. Also, results showed that higher amounts of the aliphatic hydroxyl functional groups in the KL in comparison with the SL provides higher rate of the reaction progress, leading to a superior performance for use of corresponding graft copolymer as an additive in the WBDFs. The KL-based graft copolymers were able to maintain rheological and fluid loss properties during drilling operations under the hot rolling and salt contamination.

Increased expansion ratio, cell density, and compression strength of microcellular poly(lactic acid) foams via lignin graft poly(lactic acid) as a biobased nucleating agent

Green and renewable foaming poly(lactic acid) (PLA) represents one of the promising developments in PLA materials. This study is the first to use the lignin graft PLA copolymer (LG‐g‐PLA) to improve the foamability of PLA as a biobased nucleating agent. This agent was synthesized via ring‐opening polymerization of lignin and lactide. The effects of LG‐g‐PLA on cell nucleation induced by the crystallization, rheological behavior, and foamability of PLA were evaluated. Results indicated that LG‐g‐PLA can improve the crystallization rate and crystallinity of PLA, and play a significant nucleation role in the microcellular foam processing of PLA. LG‐g‐PLA improved the foam morphology of PLA, obtaining a reduced and uniform cell size as well as increased expansion ratio and cell density. With the addition of 3 wt% LG‐g‐PLA content, the PLA/LG‐g‐PLA foams increased the compressive strength 1.6 times than that of neat PLA foams. The improved foaming properties of PLA via a biobased nucleating agent show potential for the production and application of green biodegradable foams.

Incorporating Lignin into Polyethylene Glycol Enhanced Its Performance for Promoting Enzymatic Hydrolysis of Hardwood

Polyethylene glycol (PEG) has been widely applied to improve enzymatic hydrolysis of lignocellulose by reducing enzyme nonproductive binding on lignins. To improve the performance of PEG in enzymatic hydrolysis, lignin-based surfactants were synthesized through lignin graft modification with poly(ethylene glycol) diglycidyl ether in this study. More importantly, effects of incorporating lignin into PEG on its behavior in enzymatic hydrolysis were investigated. Enzymatic hydrolysis of poplar results indicated that lignin-based surfactants exhibited better performance compared to PEG for promoting enzymatic hydrolysis. Moreover, a lower lignin-based surfactant loading was needed to achieve equal enzymatic hydrolysis. To explore the potential mechanism, changes of enzyme distribution and residual enzyme activities in supernatant after adding surfactants were determined. Quartz crystal microbalance with dissipation analysis was used to monitor the interaction between surfactants/enzyme and lignin in real-time. It revealed that the binding rates of lignin-based surfactants on lignin surfaces (1.06–1.32 min–1) were higher than those of PEG (0.43 min–1). Additionally, lignin-based surfactants respectively reduced the enzyme binding rates and maximum enzyme binding capacity on lignin by 36.7–40.9% and 43.3–64.9%, which was more significant than the reduction in enzyme binding rates and maximum enzyme binding capacity with PEG. A better understanding of this beneficial mechanism is a benefit for the design and utilization of surfactant in the lignocellulosic biorefinery process.

Synthesis and Characterization of Lignin Grafting Modification-based Aliphatic Superplasticizer

Lignin as the main component of black liquor is generally employed to modify aliphatic superplasticizer (AFS). However, the modification effect is hard to evaluate correctly due to the uncertain molecular structure of lignin and the disturbance from the complexity of black liquor compositions. In this paper, the purified lignin via acid precipitation from straw black liquor is used to modify AFS. The modified AFS named as LAFS for short presents lower molecular mass than AFS. It is assumed that it is due to the single active site of guaiacol segments in lignin by which lignin graft modifies AFS in virtue of methylolation reaction. In order to verify this assumption, guaiacol and dihydro eugenol as the typical segments of lignin macromolecule were selected, respectively, as the simplified model compounds of lignin to modify AFS, and corresponding products are abbreviated in GAFS and DAFS. Both GAFS and DAFS show the lower molecular mass than unmodified AFS. FTIR and TG-DTG analyses prove that lignin is successfully grafted onto AFS. The graft modification of lignin results in a decrease in electrostatic epulsion, but an enhanced steric hindrance. Therefore, although the replacement rate of lignin in LAFS was about 23.3%, the dispersion performance was only slightly affected.

Characteristic properties of organosolv lignin/polylactide copolymers

A polylactide (PLA)/switchgrass organosolv lignin graft copolymer was synthesized via ring-opening polymerization. The resulting copolymer was characterized by size exclusion chromatography (SEC), differential scanning calorimetry, tensile testing, and hydrogen nuclear magnetic resonance spectroscopy. Phenolic hydroxyl content, percent lignin retained, and ultraviolet (UV) light transmission were investigated by UV light spectroscopy. Hydrolytic degradation and water vapor transmission rates were also investigated.It was found that the addition of organosolv switchgrass lignin to the polymer slowed the rate of degradation and water vapor transmission rate of the copolymer compared to the PLA homopolymer at varying temperatures. UV light transmission was also reduced with the addition of lignin.

UV Cross-Linkable Lignin Thermoplastic Graft Copolymers

This work highlighted a new method to prepare UV curable lignin thermoplastic copolymers, which are expected to show applications as functional materials (e.g., carbon fiber precursors) with improved thermal stability, solvent resistance and surface hardness. UV cross-linkable lignin graft copolymers were synthesized via activator regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) and characterized. By incorporating a photosensitive compound, acryloyl benzophenone (ABP), as a comonomer during the polymerization, lignin-g-poly(styrene-co-ABP) copolymers with 6–9% (mol %) of ABP moieties were obtained. The lignin graft copolymers showed similar glass transition temperature (∼100 °C) as polystyrene. The carbon yields during pyrolysis decreased as the degrees of polymerization of the graft copolymers increased. Under UV irradiation, up to ∼30 wt % of the lignin-g-poly(styrene-co-ABP) copolymers cross-linked to form polymer networks, whereas less than ∼5 wt % of the lignin-g-p...

Preparation and evaluation of some lignin graft copolymers and their application in drilling fluid

Preparation and evaluation of some lignin graft copolymers and their application in drilling fluid

Preparation and Characterization of Lignin Graft Copolymer as a Filtrate Loss Control Agent for the Hydrocarbon Drilling Industry

Lignin graft copolymer (LGC) was prepared using an addition polymerization technique that involved grafting a 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomer onto soda lignin (SL). The optimal polymerization conditions were found to be as follows: soda lignin, 2.0 g; initiator, 3% (w/w) potassium persulphate of SL; mass ratio of AMPS to SL, 1:2; reaction time, 7 h; and reaction temperature, 60 °C. The LGC was characterized using a Fourier transform infrared (FTIR) spectroscopy, a thermogravimetric analyzer (TGA), and gel permeation chromatography (GPC). The filtrate loss controlling ability of the LGC was evaluated using the American Petroleum Institute Recommended Practice 13-B 1 standard procedures. The results showed that the LGC has remarkable rheological and filtration controlling properties at both room temperature and high aging temperatures (190 °C).

Application of Lignin from Oil Palm Biomass as a Fluid Lost Reducer

This paperexplainedthe use ofsolventnon-reactive technique with catalyst based on solution polymerization. The polymerization of Lignin as a raw material could produce a new compound as Lignin Graft Copolymer (LGC) which can be used in oilfield operation to solve fluid loss problems. In this technique, Lignin polymerize with superabsorbent polymer (SAP) using different parameters such as; heat, staring, time, and amount of catalyst. The Lignin was extracted from soda pulping process of Oil Palm Empty Fruit Bunch (OPEFB) long fibers. Lignin functional groups were characterized using Fourier TransformInfrared(FT-IR) spectroscopy.This product required further laboratory experiments to enhance its industrial applicability as a drilling fluid reducer.

Preparation and characterization of a newly water soluble lignin graft copolymer from oil palm lignocellulosic waste

Water soluble lignin graft copolymer (LGC) was synthesized using oil palm empty fruit bunch (OPEFB) fibre as a renewable biomass source. Initially, Kraft lignin (KL) was extracted by exploiting the OPEFB fibre Kraft pulping residue. KL was grafted with acrylic acid (AA) by using p-toluenesulfonic acid (PTS) as a catalyst in the condensation process via the bulk technique. The resulting copolymer was characterized by a Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetry-Fourier transform infrared (TG-FTIR) and carbon–hydrogen–nitrogen analyzer (CHN). The FTIR spectrum of the product showed absorption due to the presence of ester bonds as a proof of grafting. The DSC and TG-FTIR results showed significant improvements in the KL thermal properties at least 27.261% as well as a thermal degradation resistance. The elements percentages of KL compositions were changed as shown by the CHN data. SEM micrographs illustrated the grafting reaction homogenizing the KL morphological structure.

Lignin Graft Copolymer as Mud Thinner for Deep Well Drilling Operation

Lignin Graft Copolymer as Mud Thinner for Deep Well Drilling Operation

Lignin Graft Copolymer as a Drilling Mud Thinner for High Temperature Well

Lignin Graft Copolymer as a Drilling Mud Thinner for High Temperature Well

The effect of ions on the enzymatically induced synthesis of lignin graft copolymers.

The effect of different ions which are constituents of technical lignin sulfonates (LS) on chemo-enzymatic graft co-polymerization was determined. The application of the iron chelator desferrioxamine in the initial reaction mixture revealed that iron impurities of LS which catalyzed a Fenton-like reaction were crucial for the initiation of grafting, whereas calcium or chloride ions showed no such effect. The addition of laccase (ATCC 11235) to the reaction mixture which contained desferrioxamine caused a significantly higher yield compared to the control; this indicates a crucial effect of laccase with regard to the initiation of copolymerization. The involvement of laccase in the initiation of the graft copolymerization was additionally confirmed by the application of low molecular weight phenolics instead of LS. In the presence of the lignin-like substrates, 3,4-dihydroxybenzoic acid and guaiacol, the rate of the decomposition of t-butylhydroperoxide was significantly enhanced by laccase. It can be assumed that the enzymatically generated phenoxy radicals mediate the production of oxygen centered radicals (alkoxy or peroxy) which initiate grafting.

Fungal Biodegradation of Lignin Graft Copolymers from Ethene Monomers

Abstract White rot Basidiomycetes were able to biodegrade styrene (1-phenylethene) or methyl methacrylate (4-methyl-2-oxy-3-oxopent-4-ene) graft copolymers of lignin containing different proportions of lignin and polystyrene [poly(1-phenylethylene)] or polymethyl methacrylate [poly(1-methyl-1-(1-oxo-2-oxypropyl)ethylene)]. The biodegradation tests were run on lignin/styrene copolymerization products which contained 10.3, 32.2, and 50.4 wt% lignin while biodegradation tests were run on lignin/methyl methacrylate copolymerization products which contained 11 to 18 wt% lignin. The styrene polymer samples were incubated with white rot Pleurotus ostreatus, Phanerochaete chrysosporium, Trametes versicolor, and brown rot Gloeophyllum trabeum. The methyl methacrylate polymer samples were incubated with white rot Pleurotus ostreatus, Trametes versicolor, and Phlebia radiata. White rot fungi degraded the plastic samples at a rate which increased with increasing lignin content in the copolymer sample. Both polystyren...

Lignin graft copolymers as super water-absorbents.

Lignin graft copolymers as super water-absorbents.