method of modifying lignin with a fatty acid composition of pine oil (tofa), modified lignin and usi

专利摘要:
FUNCTIONALIZED LIGNIN AND METHOD OF PRODUCING THE SAME. The present invention relates to commercially available coniferous wood lignin, which has been esterified with pine oil fatty acid (TOFA), and tested as a barrier material in fiber based packaging material. The modified lignin samples were applied with a bar coating forming a level coating on the cardboard substrate. A significant decrease in value of WVTR and OTR was observed for card coated with modified lignin, as well as pure TOFA to be used as a reference. Unlike the TOFA coating, the modified lignin coatings exhibit a high and stable contact angle. The coating material does not affect the tensile strength of the card. According to the results, the demonstration of converting lignin into a product that added value was shown. Furthermore, the new coating material shows promising properties for development as a sustainable barrier material, in packaging material, based on fiber to replace barriers in which oil has been placed.
公开号:BR112014008321B1
申请号:R112014008321-5
申请日:2012-10-08
公开日:2021-01-12
发明作者:Tarja Tamminen；Jarmo Ropponen；Eva-Lena Hult；Kristiina Poppius-Levlin
申请人:Teknologian Tutkimuskeskus Vtt；
IPC主号:

专利说明:

[0001] [0001] The present invention relates to the modification of natural products. In particular, the present invention relates to the method of modifying lignin, the step comprising reacting at least a part of the hydroxyl groups present in the lignin in order to form a derivative thereof. Description of the Related Art
[0002] [0002] Fiber-based packaging materials have many advantages over their plastic candidates, such as renewability, recyclability and composting. However, its application is restricted due to the lower barrier properties and high sensitivity to humidity. In order to improve the barrier properties, the packaging material is laminated with aluminum or petroleum based on polymers such as PE, EVOH and PVC derivative. Since both plastic and aluminum films are problematic, choosing, recycling and recovering, replacing one or more barrier layers of them, in demanding packaging with bio-based polymers, should be more desired from a environmental view. Examples of biopolymers that have been evaluated for packaging applications are chitosan, hemicelluloses, microfibrillated cellulose and starch. However, many of the biopolymers are hydrophilic and films produced from these materials are often hydroscopic, resulting in partial loss of their barrier properties in high humidity.
[0003] [0003] Lignin is one of the most abundant natural polymers on earth. Currently, lignin is separated from wood during the pulping process. Only a small amount (1-2%) is used in specialty products, while the primary rest serves as fuel. Even if burning lignin is a valid way to reduce the use of fossil fuel, lignin has significant potential as a raw material for the sustainable production of chemicals and materials. Furthermore, in the future, bio-refineries processing lignoceculosic materials with the main purpose of producing fermentable sugars from cellulose and hemicellulose, will generate lignin in very substantial quantities. Consequently, new avenues are opening up for the use of lignin.
[0004] [0004] Lignins differ structurally depending on the source of raw material and subsequent processing, but a common feature is a main structure consisting of several types of phenyl propane units, which are linked to each other via ether or carbon-carbon bonds. They are typically replaced with methoxy groups, and the phenolic and aliphatic hydroxyl groups provide sites for, for example, additional functionalization. Lignin is known to have a low capacity to absorb water compared to, for example, hydrophilic cellulose.
[0005] [0005] Previous publications have demonstrated how lignin, containing bio-based polymer compounds, can be used as films to improve water resistance and to improve gas barrier properties. A derivative of lignin as suberin, as a paper lining material, has been shown to make it hydrophobic (Antonsson et al., 2008). However, technical lignins typically have inferior film-forming properties. Summary of the Invention
[0006] [0006] It is an objective of the present technology to improve the properties, in particular physical or mechanical properties, such as film forming properties, of lignins, in particular technical lignins and similar lignin products isolated from annual or perennial plants, such as wood , and isolated from products produced from these plants.
[0007] [0007] It is another objective to provide functionalized lignin with barrier properties.
[0008] [0008] It is also an additional objective to improve the properties of lignin and, in particular, lignin polymers, in order to allow the use of the material in areas such as applications related to insulation, adhesion, bonding, as well as compounds.
[0009] [0009] In the present context it has been discovered that hydroxyl groups present in lignin, preferably aliphatic or aromatic hydroxyl groups, can be esterified with mixtures of fatty acids, such as a mixture of natural fatty acids. In particular, the lignin hydroxyl groups can be esterified with a mixture of fatty acids containing C16 to C20 of unsaturated fatty acids. Appropriate compositions are formed by fraction of Pine Oil Fatty Acid or similar compositions.
[0010] [00010] Esterification is carried out in order to completely or partially esterify the hydroxyl groups to provide a modified lignin product that has interesting properties.
[0011] [00011] Thus, the modification of lignin with fatty acids improves the ability to form lignin films and the barrier properties of the film.
[0012] [00012] More specifically, the method according to the present invention is characterized by what is determined in the characterization part of claim 1.
[0013] [00013] The modified lignin according to the invention is characterized by what is determined in the characterization portion of claim 12. Advantageous Effects of the Invention
[0014] [00014] The present invention provides considerable advantages. Thus, as shown in the examples below, lignin esterified by TOFA- forms a film with a high and stable contact angle on the cardboard. It has good barrier properties against oxygen and water vapor and means barrier properties for aromas.
[0015] [00015] The multiple active double link functionalities in TOFA allow additional adaptation of the film properties.
[0016] [00016] Both lignin and TOFA are available from side flows of kraft pulp, and their exploitation through the invention described, for example, in the fiber-based packaging industry, improves competition in the forestry section as a whole .
[0017] [00017] Naturally, the source of raw material for lignin can be other than the kraft process, for example, lignin can originate from soda cooking, polysulfide cooking and various organosolve processes, for example, organosolve incorporating peroxo compounds.
[0018] [00018] Other than the film barrier, can be found in the field of construction (insulation foams), adhesives, plugs and compounds, to mention but a few examples. Brief Description of Drawings
[0019] [00019] Figure 1 shows SEC clearance peaks for TOFA-L-100;
[0020] [00020] Figures 2a and 2b show FTIR spectra of kraft lignin (blue line) from a) TOFA and b) Softwood (SW), TOFA_L_50 (50% target grade of TOFA substitution in SW lignin) (black line) ) and TOFA_L_100 (100% of the target grade of TOFA substitution in SW kraft lignin) (red line), standardized for the aromatic lignin range at about 1510 cm-1;
[0021] [00021] Figure 3 shows the result of a differential scanning calorimetry (DSC) analysis of esterified TOFA lignin with graphs A representing SW-, B representing TOFA-L-100 and C representing TOFA-L-50:
[0022] [00022] Figure 4 shows the change in the contact angle as time of the cardboard and the coated cardboard samples;
[0023] [00023] Figure 5 shows FE-SEM images of the surface of a) cardboard b) TOFA coating with a coverage weight of 5 g / m2 c) TOFA_L_50 coating and d) TO-FA_L_100 coating with a coverage weight of 3.9 g / m2 - 1000 x magnification for images on the left, and 10,000x for images on the right;
[0024] [00024] Figure 6 shows Molar mass distributions of TOFA- lignins;
[0025] [00025] Figure 7 shows the FTIR spectra of kraft lignin SW, TOFA_L_50 and TOFA_L_100, normalized for the aromatic lignin range at about 1510 cm-1;
[0026] [00026] Figure 8 shows contact angle measurements as a measure of surface hydrophobicity; and
[0027] [00027] Figure 9 shows an esterified TOFA-composed lignin straw. Description of Modalities
[0028] [00028] In the present technology lignin is subjected to chemical functionalization in order to form a lignin derivative having improved mechanical and physical properties. In particular, the chemical functionalization of lignin forming ester derivatives, as described here, provides an interesting way to decrease the lignin glass transition point, increase its thermoplasticity and make level films.
[0029] [00029] In the present technology, lignin is functionalized with a mixture of natural fatty acids. Preferably lignin is functionalized with Pine Oil Fatty Acid (TOFA).
[0030] [00030] TOFA is obtained from crude pine oil (CTO), a co-product of the pulp extraction process. CTO contains a mixture of fatty acids, rosin acid and non-saponifiable, and TOFA is prepared by separating fatty acids from other components by distillation and recovering the fatty acid rich fraction.
[0031] [00031] In a preferred embodiment, the hydroxyl groups of the lignin raw material are esterified with unsaturated fatty acids, which make up 80 to 99%, preferably 85 to 99%, by weight of the fatty acid composition used, which optionally contains acids saturated fatty acids, rosin and unsaponifiable acids in addition to unsaturated fatty acids.
[0032] [00032] Depending on the content of minor components, such as saturated fatty acids, rosin and unsaponifiable acids, several different degrees of TOFA are commercially available. Generally, pine oil fatty acids (TOFA) contain 85% or more fatty acids and 15% or less rosin, calculated by weight of the total mass (dry weight portion).
[0033] [00033] Preferably, the content of rosin acids in the fatty acid composition is about 0.1 to 10%, and the content of non-saponifiables is less than 5%. Particularly preferred are compositions in which the total content of rosin and non-saponifiable acids is 5% or less.
[0034] [00034] TOFA fatty acids typically contain 16 to 18 carbon atoms, the main components being unsaturated fatty acids, such as oleic and linoleic acids, having 1 and 2 double bonds (i.e., C18: 1 and C18 acids: 2, 18 carbon atoms, one and two double bonds), and linolenic and pinolenic acid, having three double bonds (i.e., C18: 3 acids).
[0035] [00035] Typically, from fatty acids, fatty acids form up to 10% C18: 3, while the main components are fatty acids containing one or two double bonds. Typically, the content of C18: 2 fatty acids is 20 to 70 parts by weight, and the content of C18: 1 fatty acids is 20 to 70 parts by weight. In a specific example, a TOFA contains approximately 95 to 98% fatty acids, and 2 to 5% total saturated and rosin acid and non-saponifiable fatty acids. Of the total fatty acid content, about 30 to 70% are C18: 2 fatty acids, and 40 to 60% are C18: 1 fatty acids.
[0036] [00036] Although the present description refers mainly to TOFA compositions, it should be noted that similar fatty acid compositions, in particular natural fatty acids, can also be derived from materials of plant and animal origin. In this way, appropriate fatty acid compositions can be obtained from various sources, such as rapeseed oil, flaxseed, hemp oil, soybean, sunflower, rapeseed, canola and olive; mustard oil, coconut, peanut, beaver and coconut oil. Fish oils and seaweed are also, in principle, useful in the present context.
[0037] [00037] It may be necessary to subject said fatty acid sources to various treatment steps, including separation process, for example, by distillation, in order to increase the proportion or purity of the fatty acid fractions.
[0038] [00038] According to the present technology, acids, mainly fatty acids, and in particular unsaturated fatty acids, of the food fatty acid raw material, such as TOFA, are covalently linked to commercially available lignin through esterification to different degrees of substitution.
[0039] [00039] Lignin contains hydroxyl groups, such as phenolic hydroxyl groups, which can be esterified. Also aliphatic hydroxyl groups can be esterified by the present technology.
[0040] [00040] The chemical nature of any lignin obtained from processing wood, is affected by (i) the lignocellulosic source and (ii) the way in which the fibers from the source were processed.
[0041] [00041] The lignin raw material preferably comprises isolated lignin. It can also comprise lignin present in an aqueous stream.
[0042] [00042] Lignins are composed of three different types of phenylpropane units, that is, p -hydoxyphenyl (H) guaiacyl (G), and si-ringyl (S) groups. Lignins isolated from soft wood (eg pine and spruce) contain mainly G units, while lignins isolated from hard wood (eg eucalyptus and birch) contain both G and S units in different proportions.
[0043] [00043] The processing of lignocellulosic fibers, by pulping or bioethanol processing, affects the chemical composition of lignin. Thus, it is assumed that lignin can be divided into smaller physical units according to its functionalities, ie guaiac, syringyl, condensates, and oxidized groups, as well as by the surface area, with variation in functionality. However, this heterogeneity of isolated lignin is probably the most significant challenge limiting its application in a wide range of value-added products. Isolated fractions of processed lignins can be expected to be more homogeneous in character, typically having different molecular mass distributions and chemical group functionalities.
[0044] [00044] The esterification of lignin can be carried out with the composition described above, by a number of esterification processes known per se. The reaction can be carried out in a liquid medium or in a dry phase. Examples of suitable methods include transesterification, esterification using reactive derivatives of acid groups (eg, anhydride acids, chloride acids), catalyzed direct esterification and the use of a screw reactor to avoid the use of a solvent.
[0045] [00045] The esterification is generally carried out at a temperature and between the melting point and boiling points of the liquid medium, in particular at 0 to 100 ° C, when operating in water at ambient pressure. Depending on the reagents, a temperature of 0 to 50 ° C can be particularly advantageous.
[0046] [00046] Conventional acid or alkaline catalysts can be used.
[0047] [00047] In one embodiment, esterification is performed in an ambient atmosphere, for example, in the presence of air. In another preferred embodiment, esterification is carried out in the presence of a reduced concentration of oxygen in relation to normal air. Preferably, the latter embodiment is carried out at an oxygen concentration in the atmosphere of less than 10% by volume, in particular less than 5% by volume, advantageously less than 1% by volume. Oxygen concentrations of 0.1 to 0.0001% by volume are appropriate.
[0048] [00048] The atmosphere can comprise inert gases. An example is the nitrogen atmosphere essentially without oxygen.
[0049] [00049] It is also possible to perform esterification under reduced pressure, for example, a pressure of 0.0001 to 0.1 bar of absolute pressure.
[0050] [00050] The lignin esters that are isolated from the reaction mixtures are purified, for example, by washing and then drying.
[0051] [00051] In the laboratory experiment discussed below, TOFA is converted to the corresponding fatty acid chloride mixture and further reacted with lignin. In this reaction, the aliphatic and phenolic hydroxyl groups are esterified with the fatty acid components of TOFA. The extent of the reaction can be adjusted by the proportion of lignin and TOFA.
[0052] [00052] Summarizing the above, the present technology comprises, in one embodiment, modifying lignin by esterifying, at least part of the hydroxyl groups present in the lignin, with a fatty acid composition of pine oil.
[0053] [00053] In a first alternative of the above modality, the method comprises esterifying at least part of the hydroxyl groups present in lignin with acids present in a fraction of pine oil fatty acid (TOFA).
[0054] [00054] The hydroxyl groups are preferably esterified with fatty acids and optionally rosin acids.
[0055] [00055] At least part of the acids used for esterification do not contain saturation, preferably the fatty acids, and optionally rosin acids, used for esterification, contain a single or multiple double bonds. Thus, the composition comprises C16 to C20 fatty acids, for example, C18 fatty acids, at least part of which is formed by fatty acids containing 2 or 3 double bonds.
[0056] [00056] The lignin to be treated comprises phenolic hydroxyl groups, aliphatic hydroxyl groups or a combination thereof, in particular the hydroxyl groups comprise syringyl, guaiac or similar groups.
[0057] [00057] By the present method, at least 50%, preferably 60 to 100% of the hydroxyl groups are substituted or esterified.
[0058] [00058] The functionalities of multiple active double bonds in TOFA also allow adaptation of the properties of the film.
[0059] [00059] Both, lignin and TOFA, are available from lateral flows of pulsating kraft, and their explorations through the invention described, for example, in the fiber-based packaging industry could improve the competitiveness of the forestry section as a whole. More generally, the source of raw material for lignin may be different from the kraft process.
[0060] [00060] As discussed above, the present technology allows the use of other sources suitable for the fatty acid components, including other vegetable oils, such as those listed above. Thus, for the purpose of esterifying lignin, according to the present technology, typically any C16 -C20 fatty acid composition can be used, in particular compositions comprising a significant portion of unsaturated C18 fatty acids. Thus, a fatty acid composition suitable for use in the present technology (regardless of origin) preferably contains at least 80%, preferably at least 85% and up to 99% by weight, of the entire solid matter, of fatty acids having 18 atoms of carbon, 90 to 100% by mass of said fatty acids, being unsaturated C18 fatty acids.
[0061] [00061] Of the fatty acid composition, C18: 2 fatty acids form 30 to 60 parts by weight, and the content of C18: 1 fatty acids is 30 to 60 parts by weight.
[0062] [00062] Esterified fatty acid lignin forms a film with a high and stable contact angle on cardboard. It has good oxygen and water vapor barrier properties and medium aroma barrier properties.
[0063] [00063] Applications other than the film barrier can be found in the construction field (insulation foams), adhesives, buffers and compounds as examples.
[0064] [00064] Lignin plasticity can be increased by appropriate additives in the formulation. However, the covalent bond between lignin and the additive prevents diffusion phenomena and, thus, stabilizes the product. Fatty acids have been linked to lignin before. However, the idea of using TOFA as a fatty acid source is new.
[0065] [00065] As such, TOFA applied to cardboard gives a high contact angle, good barrier properties against oxygen and water vapor, but lower barrier properties for aromas.
[0066] [00066] TOFA-esterified lignin can be composed at low temperature (80 ° C) without the addition of plasticizers.
[0067] [00067] Using the present products, the coating of substrates can be carried out from the solution phase or the emulsion phase or by extrusion coating. As the results tested below show, when using PLA (poly (lactic acid)) as a reference, it can be seen that lignin modified by a mixture of fatty acids of the present type, for example, a "TOFA-lignin" exhibits at least, as good results for water vapor transmission resistance (WVTR) as the extrusion processed by PLA reference. So far PLA is the only commercially available biopolymer that has been used for barrier applications. In comparison to PLA, an important advantage of the present products is that they are obtained from a non-food / inedible food raw material.
[0068] [00068] The following examples illustrate the invention. They should not be considered as limiting the scope. In particular it should be noted that, although the results have been obtained using TOFA, a mixture of fatty acids, in particular natural fatty acids, some of which are unsaturated, for lignin functionalization, there are other sources that will provide mixtures of similar fatty acids that are useful for modifying lignin. Materials and methods Synthesis and characterization of functionalized TOFA lignin Materials for synthesis
[0069] [00069] Indulin AT, (softwood kraft lignin) was received from MeadWestvaco, USA. TOFA was a gift from Forchem (Rauma, Finlância). Chloroform, ≥ 99.5%, triethyl amine, ≥ 98% and dimethylformamide, ≥ 99.8% were purchased from Fluka. Thionyl chloride, ≥ 99% was obtained from Aldrich and ≥, HPLC grade was from Rathburn. All chemicals and solvents used in this research as received. TOFA acid chloride
[0070] [00070] TOFA (50.0 g) was placed in a three-neck flask together with CH2Cl2 (100 ml) and DMF (catalytic amount). Thionyl chloride SOCl2 (42.4g, 357 moles) was added slowly to the mixture and stirred 2 hours at 40 ° C. Excess SOCl2 was evaporated and the residue was extracted three times with CHCl3 to give a brown oil in quantitative yield. 1H NMR (500 MHz, CDCl3) δ 0.86-0.90 (m, 3H, -CH3), 1.26-1.38 (m, 16H, -CH2), 1.67-1.80 (m, 2H, -CH2), 1.97-2.17 (m , 4H, -CH2), 2,752.90 (m, 3H, -CH2), 5.29-5.40 (m, 3H, -CH = CH-). 13C NMR (125 MHz, CDCl3) δ 14.0 (CH3), 22.5-31.8 (CH2), 47.0 (-CH2COCl), 127.7-130.2 (-CH = CH-), 173.6 (CO). TOFA-L-100
[0071] [00071] Lignin (Indulin AT) (8.00 g, 58.6 moles-OH based on the total OH group content of 7.33 moles / g determined by the 31P NMR analysis) was dissolved in 150 ml of DMF and triethyl amine (11.9 g, 117 moles). The mixture was cooled to 0 ° C and TOFA acid chloride (19.3 g, 64.5 moles) was added slowly. The mixture was stirred at room temperature overnight, poured into 750 ml of water and extracted with CH2Cl2 (4 * 100 ml). The organic phases were combined, dried with Na2SO4 and the solvent was evaporated. The residue was dried in vacuo to produce viscous dark brown oil. Yield 17.1 g. TOFA-L-50
[0072] [00072] Lignin (Indulin AT) (15.00 g, 7.33 mmol / g OH- group content as above) was dissolved in 150 ml of DMF and triethyl amine (11.1 g, 110 moles). The mixture was cooled to 0 oC and TOFA acid chloride (16.4 g, 55.0 moles) was added slowly. The mixtures were stirred at room temperature overnight, poured into 700 ml of water and extracted with CH2Cl2 (5 * 100 ml). The organic phases were combined, dried with Na2SO4 and the solvent was evaporated. The residue was vacuum dried to produce dark brown viscous oil. Yield: 22.3 g. Size Exclusion Chromatography
[0073] [00073] Relative molecular weights (SEC) were analyzed using THF as a mobile phase at 1 ml / min at room temperature, on HP 1050 series high pressure liquid chromatography equipment, and using a Waters Styragel RH4E column. For detection, HP 1047A RI and UV 280 nm detectors were used. Molar mass calibration was done by polystyrenes with Mw ranging from 680 to 114 000 Da. DSC Differential Scanning Calorimetry
[0074] [00074] Differential scanning calorimetry (DSC) measurements were performed with the Differential Scanning Calorimeter model Mettler Toledo DSC820 system STARe SW 9.20, Mettler Toledo GmbH, Switzerland under flowing nitrogen (flow rate 50 ml min-1) using crucibles sealed 40 μl aluminum that has been pre-treated at 500 oC to oxidize the surface and render it inert. 31P Nuclear Magnetic Resonance
[0075] [00075] Samples were phosphorylated according to the literature method (Granata and Argyropoulos, 1995). Freshly prepared samples were measured with 31P NMR immediately after preparation at room temperature. Spectra were measured on a Varian Mercury-VX 300 MHz and compiled from 512 transients using 5 seconds of pulse delay per 90o pulse. The chemical deviation scale was calibrated on the signal for phosphorylated water (132.2 ppm). FTIR
[0076] [00076] Fourier infrared transformer (FTIR) spectroscopy measurements were performed using a Bruker Equinox 55 spectrometer (Ettlingen, Germany) with an ATR sampling accessory. Gas Pyrolysis Chromatography (GC) - Mass Spectrometry (MS)
[0077] [00077] An aqueous solution of tetramethylammonium hydroxide TMAH (10% by weight / weight of aqueous solution, Merck) was used as a methylation reagent. Hyeneicosanoic acid was used as an internal standard (Fluka; purm ≥ 98%)
[0078] [00078] Pyrolysis was performed with a platinum pulse pulse pyrolizer (Pyrolab2000® from Pyrolab, Sweden) connected to a gas chromatography mass spectrometer (Varian 3800 GC-Varian 2000 MS), using a silica capillary column cast (J&W, DB-1701, 30 mx 0.25 mm, 1 μm film thickness). About 50 pg of the sample was accurately weighed and transferred to the sheet. Before adding reagent, an internal standard solution was added to the sample. The methylation reagent, 3-4 μl, was added and mixed with the sample. The sample mixed with reagent was inserted into the pyrolizer maintained at 175 ° C. Pyrolysis was carried out at 600 in 2 s. The degradation products were conducted to a capillary column for separation, using helium gas as a vehicle, flow rate 1.0 ml min-1. The column temperature was programmed from 80 ° C (2 min) to 160 ° C for 8 ° C min-1 extending from 160 ° C to 280 ° C for 5 ° C min1. The final temperature was maintained for 15 min. The mass spectrometer was operated in EI mode (70 eV). The quantification of fatty acids was based on the standard internal calibration. Coating materials, coating characterization procedure Edge sample for coating
[0079] [00079] Commercial cardboard with a base weight of 200 g / m2 was used. One side of the cardboard provided was double-coated. Coating procedure
[0080] [00080] TOFA-modified lignin samples were diluted in acetone to 17% by weight / weight and the TOFA reference coating, with a cover weight of 5.0 g / m2, was diluted with acetone to 50% in weight / weight. An Erichsen coater with a wire diameter of 40 μm was used to coat the cardboard. The application rate was 12 mm / s. The samples were applied as a single or double coating layer on the double coated cardboard. Coating weight
[0081] [00081] The weight of the coating was determined using a Mettler HK 160 balance. The samples were conditioned at 23 ° C and 50% relative humidity for 4 hours before weighing. Field Emission Scanning Electron Microscopy
[0082] [00082] The coating surface was characterized by Field Emission Scanning Electron Microscopy (FE-SEM; Zeiss (now LEP) DSM 982) operated at 0.6 and 1.0 kV with 1000 and 10000 magnifications. Tensile strength
[0083] [00083] All samples were conditioned and tested at 23 ° C and 50% relative humidity before measurements. Tensile strength was measured in an L&W tensile strength tester (Lorentzen and Wettre Oy) according to ISO 1924-2: 2008. Oxygen Transmission Rate
[0084] [00084] The oxygen transmission rate (OTR) was determined with the Model 8001 Oxygen Permeation Analyzer (Systech Instruments Ltd., United Kingdom) according to the ASTM F2622-08 standard, over an exposed surface area of 5 cm2 . The tests were carried out at 23 ° C and 50% relative humidity. The oxygen transmission rate was expressed as cm3 m-2 24h-1. Water Vapor Transmission Rate
[0085] [00085] The measurements of the Water Vapor Transmission Rate (WVTR) were determined gravimetrically, according to a modified ASTM E-96 procedure. Samples with a test area of 30.2 cm2 were mounted on a circular aluminum plate (H.A. Buechel V / H, A.v.d. Korput, Baarn-Holland 45M-141), which contained water. The dishes were stored at 23 ° C and 50% relative humidity and weighed periodically, until a constant weight reduction was achieved. Contact angle
[0086] [00086] Contact angles of 5 μΙ of water in drops on the coating were measured at 23 ° C and 50% relative humidity, using a CAM 200 device (KSV Instruments Ltd). Five measurements at different positions on the film surface were made and the mean was determined. Results: Characterization of functionalized lignin by TOFA SEC, Nuclear Magnetic Resonance 31P and FTIR
[0087] [00087] SEC results can only be compared between modified samples, since the starting material was not soluble in the solvent used in SEC. When comparing molecular weights, TOFA-L-50 is 58% modified compared to TO-FA-L-100 and this is in line with theoretical results. The clearance curves are shown in Fig. 1. They indicate that the molecular weight distributions are quite narrow in both cases (50%).
[0088] [00088] Furthermore, 31P NMR shows clear evidence that all hydroxyl groups in TOFA-L-100 are fully modified (results are shown in slightly different ways in Tables 1A and 1B):
[0089] [00089] As will be evident, practically all the aliphatic and phenolic hydroxyl groups have been replaced when aiming at a complete replacement. The lower TOFA charge left the hydroxyl part intact.
[0090] [00090] Only a quantity of hydroxyls of carboxylic acid is increased from a value of 0.34 mmol / g to 0.96 mol / g which suggests that the sample contains 0.62 mmol / g in excess of free TOFA. The 0.62 mol / g increase in carboxylic hydroxyls means that the TOFA-L-100 sample includes approximately 1% acid-free, which is below the FTIR detection limit and thus no TOFA is not obtained by FTIR . For TOFA-L-50, the 31P NMR showed that 75% of the hydroxyl groups were esterified, which is a slightly higher value than the 58% determined by GC-MS thermochemical chemotherapy and the theoretical 51%. The reason for the higher value than the theoretical level of substitution is probably the heterogeneity of the reaction mixture, which makes it possible to enrich the hydrophobic material, most highly modified in the organic phase during extractions. Furthermore, based on the decreased proportion between phenolic and aliphatic hydroxyl groups in esterification, the phenolic hydroxyl groups seem to react preferentially. Also for TOFA-L-50, a small increase in carboxylic hydrolysis based on 31P NMR was obtained, but the value calculated for free TOFA (0.3%) is too small to affect the barrier properties.
[0091] [00091] The total amount of fatty acids was investigated by methylation pyrolysis in situ (Table 2).
[0092] [00092] The structural composition of TOFA, lignin and lignin functionalized by TOFA was verified with FTIR (ATR mode) and the spectra are shown in Fig. 2.
[0093] [00093] The peaks at 2925 cm-1 and 2854 cm-1 are assigned to long chain alkyl groups (aliphatic carbon) and are clearly present in TOFA and in functionalized TOFA lignin samples. The peaks at 1599 cm-1, 1508 cm-1 and 1451 cm-1 are specific for lignin and also for modified TOFA lignins and are designated for aromatic skeletal vibrations. In TOFA there is also the carbonyl group present at 1706 cm-1. In the modified TOFA lignin samples, the appearance of two new peaks at 1739 cm-1 and 1762 cm-1 is seen. They are provided for aliphatic ester bonding and phenolic ester bonding, respectively, and indicate esterification of lignin and TOFA.
[0094] [00094] Both TOFA-L-100 and TOFA-L-50 showed Tg at a much lower temperature compared to Indulin AT as such (Fig 2). TOFA-L-100 showed Tg below 0 ° C, a relaxation peak can be obtained first and then after Tg release the peak. Because of this, the value of ΔCp is so small for TOFA-L-100. In addition, the phenomenon after 170 is most likely caused by degradation. For TOFA-L-50 obtaining Tg is a very wide extension starting at about -30 ° C and ending at more than 50 ° C. This wide glass transition temperature also causes a small ΔCp. In addition, weak ΔCp changes around 80 ° C is also obtained. The broad Tg is also a small ΔCp exchange at 80 ° C and may be caused by the heterogeneity of TOFA-L-50 based on different levels of substitution.
[0095] [00095] Figure 3 shows the results of the Differential Scanning Calorimetry (DSC) analysis of lignin esterified by TOFA. A) SW- lignin, B) TOFA-L-100 and C) TOFA-L-50 using the instruments mentioned above.
[0096] [00096] The samples were heated and cooled twice at a rate of 10oC / min from -60oC to 200oC. An appropriate amount of sample (ca. 5-10 mg) is weighed in a weighing pan. The pans were closed by cold pressure. Holes were punctured in the lid to release any pressure forming in the pan due to increased temperature or solvent evaporation. The DSC calibration was performed using the melting temperatures and enthalpies of hexane, water, indium, and zinc at heating rates of 2, 5, 10, and 20 K / min. The glass transition temperatures were determined from the half point. Characterization of cardboard coated with lignin functionalized by TOFA
[0097] [00097] Water vapor transmission rate and contact angle The capacity of the lignin modified by TOFA and TOFA to act as a moisture barrier was investigated by determining the WVTR. A significant decrease in WVTR was observed for TOFA-modified lignin samples and TOFA-coated cardboard compared to the reference cardboard sample (Table 3). Table 3 shows oxygen rates (OTR) water vapor transmission (WVTR) of TOFA and TOFA- functionalized lignin (single coating layer)
[0098] [00098] Both the lignin and TOFA samples act as good oxygen and water vapor barriers; TOFA as such is, however, even better.
[0099] [00099] Furthermore, the contact angle was determined in order to quantitatively measure the humidity of the coating by water. The change in contact angle with time of a drop of water placed on the coverings was monitored and the results are shown in Fig. 4.
[0100] [000100] All coatings studied (TOFA_L_50 and TO-FA_L_100), except TOFA coatings, exhibited a high and constant contact angle (for two minutes). It is possible that the surface structure as such and also the surface chemistry of functionalized TOFA lignin coatings are different compared to TOFA coatings, thereby showing a high and stable contact angle.
[0101] [000101] The results show that the cardboard coating with lignin modified by TOFA or TOFA decreases its rate of water vapor transmission and that a high and stable contact angle is achieved. These two observations demonstrate that this application can be an efficient way to prolong the application of paper materials based on packaging materials. Oxygen transmission rate
[0102] [000102] OTR values for cardboard (reference), TOFA-coated cardboard and TOFA-functionalized lignin are shown in Table 3. OTR values decrease significantly with the application of a TOFA coating layer or TOFA-functionalized lignin. It seems as if the TOFA coating is capable of providing a better oxygen barrier compared to TOFA functional lignin at similar coating weights (Table 3).
[0103] [000103] Both, a thick coating layer (TOFA only) and a double layer of TOFA_L_100 resulted in even lower OTR values. The reduction in OTR can be interpreted in terms of closing the surface pores of the cardboard (REF).
[0104] [000104] In fact, a material is defined as a high oxygen barrier if OTR is less than 3 cm3 / m2x24h (at 25 ° C, 50% RH) for a 25 μm film thickness. Although a reduction in OTR is observed for the coating materials investigated, the values are not low enough to be considered as a "high oxygen barrier", which can probably be explained by the fact that a homogeneous and continuous film was not fully formed.
[0105] [000105] In Fig. 5, images of TOFA coating SEM with a coating weight of 5.0 g / m2, TO-FA_L_50 coating and TOFA_L_100 with a coating weight of 3.9 g / m2 are shown . As seen in the larger enlarged images (10000x), SEM images reveal slight lack of homogeneity of the film for the coatings of TOFA_L_50 and TOFA_L_100 (3.9 g / m2). Since TOFA has a transparent color, it is difficult to assess the quality of the coating since basically the underlying edge is visible. Even if the dimensions of the inhomogeneities are on the nanometer scale, it allows the passage of oxygen molecules that have a van der Waals diameter of about 0.3 nm, thus influencing the OTR value.
[0106] [000106] Figure 6 shows the molar mass distributions of TOFA lignins. The upper image shows the SEC analysis in THF for TOFA_L_100, Mn4004, Mw 46,068, polydispersity (Mw / Mn) 11,507 and the lower image shows the SEC analysis in THF for TOFA_L_50, Mn 4,661, Mw: 26,556, polydispersity (Mw / Mn): 5.697.
[0107] [000107] Figure 7 shows the FTIR spectra of kraft lignin SW, TOFA_L_50 and TOFA_L_100, normalized for the aromatic lignin range of about 1510 cm-1. Tensile strength
[0108] [000108] The tensile strength was determined for the cardboard and the coated cardboard samples (TOFA, TOFA_L_50 and TOFA_L_100). As can be seen in Table 4, the cardboard and all coated cardboard samples exhibit a similar tensile strength, which means that the coatings do not affect the tensile strength of the cardboard.
[0109] [000109] TOFA functionalized lignin has medium aroma barrier properties while TOFA has inferior ones.
[0110] [000110] As will be seen from the above, commercially available lignin (exemplified by Indulin AT) can be esterified with pine oil fatty acid to different degrees of substitution, as used for barrier application in fiber based packaging materials.
[0111] [000111] The products obtained, the functionalized lignin material, both contained reacted and unreacted TOFA.
[0112] [000112] Cardboards coated with TOFA-functionalized lignin exhibit a significant reduction in the water vapor transmission rate and oxygen transmission rate.
[0113] [000113] The new lignin coating material functionalized by TOFA can be exploited as a sustainable barrier material, thereby replacing the conventional petroleum based barrier material.
[0114] [000114] Although the above description discusses the use of fatty acids contained in TOFA compositions, it is clear that there are also some rosin acids (typically less than 10% by weight, in particular 5% by weight or less) present in TOFA . These acids can also, to some extent, take part in the reaction with the lignin hydroxyl groups.
[0115] [000115] Table 6. WVTR and OTR of lignin palmitate (C16), laurate (C12) and ester-coated cardboard TOFA- standardized, the coating weight of 10 g / m2. (TOFA-L-100: all esterified hydroxyl groups; TOFA-L-50: 50% of the total esterified hydroxyl groups)
[0116] [000116] As will be evident from the results, TOFE-modified lignin is at least as good, or even better, compared to WVTR as the PLA coated extrusions used for reference.
[0117] [000117] Figure 8 shows contact angle measurements as a measure of surface hydrophobicity.
[0118] [000118] Figure 8 indicates that an edge coated with TOFA- lignin (both samples) has a high contact angle and is stable as a function of time. A TOFA-coated edge, as such, has a contact angle that is not stable, which can be attributed to porosity; and
[0119] [000119] Figure 9 shows that a continuous straw could be produced from lignin esterified by TOFA. In the present case, no plasticization was necessary. The compound was carried out at 80 ° C with an agitation rate of 150 rpm. The straw shown in Figure 9 was soft and elastic even at room temperature.

权利要求:
Claims (6)
[0001]
Lignin modification method, characterized by the fact that it comprises esterifying at least part of the hydroxyl groups present in the lignin with a pine oil fatty acid (TOFA) composition, in which at least 50% of the hydroxyl groups are esterified.
[0002]
Method according to claim 1, characterized in that a pine oil fatty acid composition is used for esterification, comprising C16 to C20 fatty acids, at least a part of which is formed by fatty acids containing 2 and, optionally , 3 double bonds.
[0003]
Method according to claim 1 or 2, characterized in that the lignin comprises phenolic hydroxyl groups, aliphatic hydroxyl groups or a combination thereof.
[0004]
Method according to any one of claims 1 to 3, characterized in that the fatty acid composition contains 0.1 to 10% rosin acids, calculated by weight of the composition's solid matter.
[0005]
Modified lignin, characterized by the fact that it is obtained by a method as defined in any one of claims 1 to 4.
[0006]
Use of modified lignin as defined in claim 5, characterized by the fact that it is for the production of films, for coating substrates, and for producing insulation foams, adhesives, binders and composites.

类似技术:

---

公开号 | 公开日 | 专利标题

---

BR112014008321B1|2021-01-12|method of modifying lignin with a fatty acid composition of pine oil |, modified lignin and using it

---

Hult et al.2013|Enhancing the barrier properties of paper board by a novel lignin coating

---

Crouvisier-Urion et al.2016|Biobased composite films from chitosan and lignin: antioxidant activity related to structure and moisture

---

Meng et al.2017|An in‐depth understanding of biomass recalcitrance using natural poplar variants as the feedstock

---

Chiplunkar et al.2016|Utilization of sunflower acid oil for synthesis of alkyd resin

---

Lu et al.2004|Development of a fast drying lacquer based on raw lacquer sap

---

Baumberger et al.1998|Utilization of pine kraft lignin in starch composites: impact of structural heterogeneity

---

İşeri-Çağlar et al.2014|Preparation and evaluation of linseed oil based alkyd paints

---

Kisonen et al.2015|Composite films of nanofibrillated cellulose and O-acetyl galactoglucomannan | coated with succinic esters of GGM showing potential as barrier material in food packaging

---

Cheng et al.2012|Synthesis of biobased phenolic resins/adhesives with methylolated wood‐derived bio‐oil

---

Passauer et al.2012|Dynamic moisture sorption characteristics of xerogels from water-swellable oligo | lignin derivatives

---

Hult et al.2013|Esterified lignin coating as water vapor and oxygen barrier for fiber-based packaging

---

Shao et al.2019|Facile and green preparation of hemicellulose-based film with elevated hydrophobicity via cross-linking with citric acid

---

Sousa et al.2016|Xylan and xylan derivatives—Their performance in bio-based films and effect of glycerol addition

---

Wen et al.2011|Homogeneous lauroylation of ball-milled bamboo in ionic liquid for bio-based composites production: part I: modification and characterization

---

Yang et al.2015|Effects of polysaccharides on the properties of Chinese lacquer sap

---

Michelin et al.2020|Carboxymethyl cellulose-based films: Effect of organosolv lignin incorporation on physicochemical and antioxidant properties

---

Xing et al.2018|Development and characterization of a new bio-adhesive for wood using cassava starch and bio-oil

---

Hua et al.2019|Aqueous dispersions of esterified lignin particles for hydrophobic coatings

---

Söyler et al.2017|Catalytic transesterification of starch with plant oils: a sustainable and efficient route to fatty acid starch esters

---

Melro et al.2020|Levulinic acid: A novel sustainable solvent for lignin dissolution

---

Xue et al.2020|Efficient dissolution of lignin in novel ternary deep eutectic solvents and its application in polyurethane

---

de Menezes et al.2016|Physicochemical characterization of residue from the enzymatic hydrolysis of sugarcane bagasse in a cellulosic ethanol process at pilot scale

---

Zhang et al.2015|Morphological variation of lignin biomacromolecules during acid-pretreatment and biorefinery-based fractionation

---

Moubarik et al.2015|Understanding the physicochemical properties of olive kernel to be used as a potential tool in the development of phenol-formaldehyde wood adhesive

同族专利:

---

公开号 | 公开日

---

US20140243511A1|2014-08-28|

---

DK2751169T3|2018-11-26|

---

EP2751169B1|2018-08-08|

---

US9902815B2|2018-02-27|

---

WO2013050661A1|2013-04-11|

---

EP2751169A4|2015-04-08|

---

EP2751169A1|2014-07-09|

---

BR112014008321A2|2017-04-18|

引用文献:

---

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

---

---

US2429102A|1943-02-13|1947-10-14|Mead Corp|Esters of lignin material|

---

US3149085A|1958-10-20|1964-09-15|West Virginia Pulp & Paper Co|Method of making synthetic resin from lignin and an epoxide and resulting product|

---

US4017430A|1975-06-23|1977-04-12|Georgia-Pacific Corporation|Coating composition|

---

US5773590A|1997-04-08|1998-06-30|Betzdearborn Inc.|Methods of separating lignin solids and black liquor from tall oil fatty acids|

---

US6172204B1|1999-06-04|2001-01-09|Regents Of The University Of Minnesota|Compositions based on lignin derivatives|

---

US7977399B2|2006-10-05|2011-07-12|Kaneka Corporation|Curable composition|

---

FI20085345A|2008-04-22|2009-10-23|Kemira Oyj|A method for reducing yellowing of lignin-containing material by light|

---

US20100152428A1|2008-12-12|2010-06-17|Weyerhaeuser Company|LOW Tg LIGNIN MIXED ESTERS|

---

US8664305B2|2009-02-10|2014-03-04|The Goodyear Tire & Rubber Company|Functionalized lignin, rubber containing functionalized lignin and products containing such rubber composition|

---

WO2010106182A1|2009-03-20|2010-09-23|Sika Technology Ag|Method for producing chemically modified lignin decomposition products|

---

US20100311876A1|2009-06-05|2010-12-09|Weyerhaeuser Nr Company|Lignin ester extended polyphenylene oxide based polymers|

---

US20100331531A1|2009-06-25|2010-12-30|Eastman Chemical Company|Methods for esterifying lignocellulosic material|FI20125879A|2012-08-24|2014-02-25|Upm Kymmene Corp|Process for the esterification of lignin with at least one fatty acid|

---

US10059730B2|2013-03-15|2018-08-28|Renmatix, Inc.|High purity lignin, lignin compositions, and higher structured lignin|

---

HUE041358T2|2013-09-27|2019-05-28|Stora Enso Oyj|A composition comprising lignin and epoxy compound for coating and method for the manufacturing thereof and use thereof|

---

AU2014336965A1|2013-10-18|2016-06-02|Queensland University Of Technology|Lignin-based waterproof coating|

---

ES2895101T3|2013-12-16|2022-02-17|Ren Fuel K2B Ab|Composition comprising esters of lignin and oil or fatty acids|

---

CN107074981A|2014-09-26|2017-08-18|瑞恩麦特克斯股份有限公司|The composition of containing cellulose and its manufacture method|

---

WO2016134162A1|2015-02-18|2016-08-25|Nutech Ventures|Methods of making and using lignin derivatives|

---

EP3307950A4|2015-06-11|2019-04-17|Tyton Biosciences, LLC|Process and system for producing pulp, energy, and bioderivatives from plant-based and recycled materials|

---

CN107922856B|2015-06-15|2021-05-18|雷恩生物燃料公司|Compositions comprising derivatized lignin for fuel production|

---

FI126754B|2015-11-25|2017-05-15|Teknologian Tutkimuskeskus Vtt Oy|Functionalization of cellulose with lignin to produce high quality products|

---

CN109476879A|2016-12-15|2019-03-15|雷恩生物燃料公司|Polymer material comprising modified lignin resin|

---

EP3409727A1|2017-05-29|2018-12-05|Annikki GmbH|Method for the preparation of a lignin prepolymer|

---

US11028249B2|2017-08-31|2021-06-08|National Technology & Engineering Solutions Of Sandia, Llc|Methods of synthesizing ionic liquids from primary alcohol-containing lignin compounds|

---

AU2019206607A1|2018-01-12|2020-07-16|Circ, LLC|Methods for recycling cotton and polyester fibers from waste textiles|

---

EP3933011A4|2020-07-01|2022-01-05|Ren Fuel K2B Ab|Lignin esterified with a mixture of saturated and unsaturated fatty acids|

---

EP3932993A1|2020-07-01|2022-01-05|Ren Fuel K2B AB|Lignin crosslinked with a polyunsaturated compound|

法律状态:
2018-03-27| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

---

2020-06-16| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application [chapter 6.1 patent gazette]|

---

2020-10-27| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

---

2021-01-12| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 08/10/2012, OBSERVADAS AS CONDICOES LEGAIS. |

---

2021-04-20| B25A| Requested transfer of rights approved|Owner name: TEKNOLOGIAN TUTKIMUSKESKUS VTT OY (FI) |

---

2021-05-11| B25G| Requested change of headquarter approved|Owner name: TEKNOLOGIAN TUTKIMUSKESKUS VTT OY (FI) |

优先权:

---

申请号 | 申请日 | 专利标题

---

US201161544303P| true| 2011-10-07|2011-10-07|

---

US61/544,303|2011-10-07|

---

PCT/FI2012/050965|WO2013050661A1|2011-10-07|2012-10-08|Functionalized lignin and method of producing the same|

---