CA1288765C - Lignin having sulfur and phosphorus groups - Google Patents
Lignin having sulfur and phosphorus groupsInfo
- Publication number
- CA1288765C CA1288765C CA000553716A CA553716A CA1288765C CA 1288765 C CA1288765 C CA 1288765C CA 000553716 A CA000553716 A CA 000553716A CA 553716 A CA553716 A CA 553716A CA 1288765 C CA1288765 C CA 1288765C
- Authority
- CA
- Canada
- Prior art keywords
- lignin
- product
- sulfur
- phosphorous
- lignin material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08H—DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS
- C08H6/00—Macromolecular compounds derived from lignin, e.g. tannins, humic acids
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07G—COMPOUNDS OF UNKNOWN CONSTITUTION
- C07G1/00—Lignin; Lignin derivatives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L97/00—Compositions of lignin-containing materials
- C08L97/005—Lignin
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B59/00—Obtaining rare earth metals
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B60/00—Obtaining metals of atomic number 87 or higher, i.e. radioactive metals
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- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Polymers & Plastics (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Biochemistry (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Compounds Of Unknown Constitution (AREA)
Abstract
ABSTRACT
LIGNIN HAVING SULFUR AND PHOSPHORUS GROUPS
A product comprising lignin material having a sulfur content greater than 5%, a phosphorus content greater than 3%, and wherein the mole ratios sulfur to aromatic unit S/Ar>0.4, and phosphorus to aromatic unit P/Ar:>0.3, and wherein Ar in said mole ratio is arbitrary set to define a mole of an aryl propane unit having an average molecular weight of 242. On IR analysis the product has infra-red absorption bands for the aromatic groups, P=S groups, CH2-S groups, P-O-C groups, P-O-Ar groups. The product may be used for instance in chelation, as flame retardant, for agricultural and other end uses. The invention is also directed at a method of making the above product which comprises reacting a lignin containing material with phosphorus pentasulfide (P4S10): for example by reacting in a solvent or melting.
LIGNIN HAVING SULFUR AND PHOSPHORUS GROUPS
A product comprising lignin material having a sulfur content greater than 5%, a phosphorus content greater than 3%, and wherein the mole ratios sulfur to aromatic unit S/Ar>0.4, and phosphorus to aromatic unit P/Ar:>0.3, and wherein Ar in said mole ratio is arbitrary set to define a mole of an aryl propane unit having an average molecular weight of 242. On IR analysis the product has infra-red absorption bands for the aromatic groups, P=S groups, CH2-S groups, P-O-C groups, P-O-Ar groups. The product may be used for instance in chelation, as flame retardant, for agricultural and other end uses. The invention is also directed at a method of making the above product which comprises reacting a lignin containing material with phosphorus pentasulfide (P4S10): for example by reacting in a solvent or melting.
Description
~his invention relates to a product derived from lignin containing materials having sulfur and phosphorus groups, and to a method making same. This invention is particularly directed to such lignin materials comprising the steps of reacting lignin with phosphoru~ pentasulfide to be used for instance in chelation, as flame retardants, and for agriculture uses.
PRIOR ART
Traditional ion exchange resins contain functionalities capable of exchanging their cations, as in the case of sulfonated or phosphorylatad materials, or of exchanging their anions, as in ~uaternary aminated product~. These materials are generally synthesized in granular or spherical bead form through the polymerization of ethylenically unsaturated monomers such as styrene or acrylic acid and a cross-linking agent such as divinylbenzene to render them insoluble in a particular solvent. The monomer~ may be modified to include desired functional groups prior to the polymerization of the preformed polymeric matrix and/or they may be subsequently chemically modified to achieve the desired acid or base form. The capacities o~ these materials arQ generally expre~sed in milliequivalents active protons per gram o~ cakionic resin (meq/g) or in meq/g exchangeable chloride for the anionic resins, or sometimes referred to as: (mmol/g) as it will be used in this application.
Ion exchange resins have been used extensively in the removal of metal ions from aqueous solutions for such purposes as wa~er softening, treatment of radioactive wastes, or the purification of industrial effluents ~k , ,:
containing heavy or toxic metals. These resins have also found application in the commercial isolation of metal ions such as uranium, in the purification and separation of the fourteen rare earths and yttrium for the fabrication of semi- and super- conductors, in the recovery of chromium from spent metal plating solutions and zinc and copper from waste occuring in the synthetic f iber industry, and in the industrial isolation of precious metals such as gold and platinum in mining and their purification in electronics.
The high cost and low selectivity of most commercial ion exchangsr6 have prevented their technological use in the large scale purification of metals, uranium and gold being the exceptions, even though these resins are preferred for the analytical isolation of many different metals. The need for more selectivity in the industry has led to the develop-ment of ion exchange resins which are capable of binding preferentially a certain metal ion in the pre~ence of others of the same charge. The numerous iminodiacetic acid based resins all show preference for the first row transition metals, but they are not very selective for specific metal ions. Multiple stage elution / adsorption cycles are needed to achieve separation of several metal components~ Specialty metal ion binders have been developed for metals such as copper, gold, iron, mercury, radium and uranium. Such chelators are usually manu~ac~ured from cross-linked polystyrene or cross-linked acrylate polymer backbones, which have been elaborated to contain specific metal ion binding sites. As these site3 strongly bind the particular metal ion, elution o~ such metals from these resins usually require drastic conditions to the point of complete ashing --4 ~ 876~
of the polymer.
Increasing precious metal prices make the leaching of low grade ores profitable only, if such metals can then be selectively isolated from the pregnant solutions containing a variety of other components usually in much greater amounts.
As yet, the mining industry prefers the use of coconut shell charcoal ion exchangers to that of any synthetic resin due to their selectivity for gold and silver. Coconut shell charcoal is expensive and must therefore be regenerated at an added cost. It is fragile (up to 8% is lost in every extraction cycle along with any bound gold) and has very low capacity compared with thak of the synthetic resins. However, most resins do not discriminate enough between different metal ions and, those which do are not easily freed of their gold.
THE INVENTION
Broadly stated, the invention is directed to a product comprising lignin material substantially water insoluble at neutral or acid pH having a chemically bound sulfur content of at least 9.5~ and a phosphorous content from 3.3 to 10% by weight of the lignin material, at least 50~ by weight of said sulfur and phosphorous being in the form of thiophosphate and wharein in said lignin material the mole ratio of sulfur to phosphorous S/P is at least 1.8, sulfur to aromat~c unit, S/Ar is at least 0.7 and phosphorous to aromatic unit P/Ar is from 0.3 to 0.8, wherein said Ar in said mole ratios is arbitrarily set to define an aryl propane unit having an average molecular weight of 242, said lignin material has infra-red absorption bands evidencing P=S groups in the vicinity of 730-7~0 cm~1, P-S or Ar-S groups in the vicinity of 640-670 cm~l, P~O-Ar groups in the vicinity of 1080-1110 cm~l, aromatic groups in the ,~ .
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vicinity of 1490-1510 cm~1, CH2-S groups in the vicinity of 820~845 cm~1, P-0-C groups in the vicinity of 965-995 cm~l, said product being substantially free from sulfur which is not chemically bound to said lignin material, said lignin material having chelating capacities for gold at p~ 2 of at least 2.2 millimoles per gram of said lignin material and wherein when said product is free from ether and other groups absorbing in the region of 1080-1110 cm~1, the sum of the intensity of the bands in the vicinity of 640-670 cm~l and 730-750 cm~1 over the intensity of the band in the vicinity of 1080-1110 cm~l is greater than l and when said product comprises ether and other groups absorbing in the region of 1080-1110 cm~l, the sum of the intensity of the bands in the vicinity of 640-670 cm~l and 730-750 cm~l over the intensity of the band in the vicinity of 1080-lllO cm~l less the intensity in said region by said ether and said other groups absorbing in the region 1080-1110 cm~l, is greater than 1.
The invention is also directed to a method of making the above product which comprises: heating under anhydrous conditions a product containing lignin material with at least a molar equivalent ratio of phosphorous pentasulfide (P4S1o) to lignin of said lignin material, said lignin being arbitrarily set to define an aryl propana unit to obtain as a reaction product a lignin material having chemically bound a sulfur ~ontent greater than 9.5% and a phosphorous content from 3.3 to 10%, wherein the mole ratio S/P is at least 1.8 that comprises one of the following steps:
a) collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below to avoid a reaction, inherent to said reaction - ~b - ~ ~87~S
product, producing unbound sulPur, and then rapidly contacting said ~uenched reaction product with water haviny acidic pH, to precipitate out the lignin material chemically bound to sulfur and phosphorous and to leave in said water having acidic pH, said unbound sulfur, the ; reactants producing said unbound sulfur and the excess amount of phosphorous pentasulfide forming an acqueous solution with said acidic water, and rapidly filtering said ?aqueous solution to collect the precipitate of the lignin material chemically bound to sulfur and phosphorous substantially free from said chemically unbound sulfur, b) once said reaction product is obtained, collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below, then contacting said quenched reaction product with water having acidic p~ to precipita-te out the lignin material chemically bound to sulfur and phosphorous and some of the unbound sulfur and filtering said aqueous solution to collect the precipitate o~ the lignin material chemically bound to sulfur and phosphorous and the pxecipitate of unbound sul~ur, and further washing with a solvent dissolving said unbound sulfur while maintaining insoluble said lignin ma~erial chemically bound to sulfur and phosphorous to obtain said lignin material chemically bound to sulfur and phosphorous substantially free from said unbound sulfur, c) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, the amounts of P4Slo in said molar equivalent ratio being no greater than that required to react with the cellulose ~ ~ d ,". ~' ' ' ~ ',,, ' ' ':
- 'Ic ~B~Ç;5 fraction of said lignocellulose, once said reaction product is obtained cooling said reaction product said lignin material chemically bound to sulfur and phosphorous substantially free from any major amount of chemically unbound sulfur, the excess of said molar ratio unreacted with the lignin having reacted with the cellulose fraction, d) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, said molar equivalent ratio being greater than that required to react with the cellulose fraction of said lignocellulose and carrying out the method with one of steps a) and b).
By lignin containing materials is meant a product which is 100% lignin or which contains as substrate a lignin, or if desired, other additives and lignin, or chemically modified lignin such as those having other compatible functional groups, i.e. not susceptible to react with P4S1o/ nor lnterfering with the aims of this invention: that is, partaking in the reaction to produce the functional groups that are desired e.g. P-S, ; 20 P=S, C-S, O-P and not to hinder the reaction to produce them:for example, lignin sulfonate or other functional groups as lignin triazines, Lignin -C=O, lignin - COOH, lignin -CH2-NH2.
Other typical examples are products derived from hard- or soft-wood and including wood fibers themselves. The lignin used has generally a molecular weight greater than 500.
The product is cross-linkable if one desires, with cross-linking agent such as formaldehyde and may be cross-linked with other cross-linking agents that are compatible with the functional groups of the product, such as di-halogenated reagents, bis-epoxides and other known compatible cross-linking .~
,. ~v - 5 - ~8B765 agents.
DRAWINGS
In the drawings which illustrates particular embodiments of the invention.
Figure l to 12 represent IR spectra of the products obtained form Example 1 to 12 respectively, wherein the abscissa represents the frequency from 400 to 4000 cm~l as expressed in the Figures and the ordinate represents relative absorbance.
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' 76~;
Figure 13 to 24 represent the i~otherm obtained from Examples 1, 2 and 4 respectively wherein:
Figure 13 is the isotherm from Example 1 in 0.
Figure 14 is same a~ in Figure 13 with untreated lignin.
Figure 15 is the isothem from Example 1 in N.
Figur~ 16 is same as in Figure 15 wikh untreated lignin.
Figure 17 is the isothem from Example 2 in 0.
Figure 18 is ~ame as in Figure 17 with untreated lignin.
Figure 19 is the isothem from Example 2 with N.
Figure 20 is the same as in Figure 19 with untreated lignin.
Figure 21 is the isothem from Example ~ in 0.
Figure 22 is same a~ in Figure 21 with untreated lignin.
Figure 23 i~ the i~othem from Example 4 in N.
Figure 24 is the same as in Figure 23 with untrsated lignin, and wherein the abscissa represents the temperature in Centigrade and the ordinate for the curves TG~ (thermo gravimetic analysi~) represents %
weight loss of the sample being analy~ed versus temperture T, and the curves related to differential thermal analysis (DTA) or dT/T indicative of the heat content or enthalpy of the product being analyzed by the relation dT, wherein dT is the difference in temperature against a standard versus a given temperture T in oxygen (0) or nitrogen (N).
'''''"'' ~387~S
THE PREFERRED WAYS OF CARRYING OUT T~E INVENTION
One of the preferred ways o~ carrying out the invention consists in diesolving lignin in a suitable solvent and then adding phosphorus pentasulfide taking care of the exothermic reaction, and then refluxing the reaction mixture.
Preferably the molar ratios of lignin to P4Slo range from 1:1 to 1:10 and most preferably 1:1 to 1:2.
Amongst preferred solvents are dioxane, and pyridine.
Other solvents dissolving lignin and compatible with the reactants, may al80 be used, if desired: for instance, dimethylsulfoxide, dimethylformamide, tetrahydrofuran.
AqueouG media should be avoided, as they tend to hydrolyze the P4slo~
The reaction time and tempQrature determines the amount of P-S addition but should be at least 2 hours at room temperature or above~ Pressure may be used if desired.
Prefexably, the temperakure ranges between 20 to 180C and most preferably in the vicinity of 110C.
For instance, new materials with sulfur contents in the range 17.11-18.90~ and phosphorus contents 5.36-9.03% are easily attainable by reacting lignin derived from hardwood with phosphorus pentasulfide in pyridine at elevated temperatures for periods of the order of 40 hours. Lowex incorporations are attainable at room tempera~ure in the order of (S:11.5il.5%, P:303+2.5~) or with reactions at reflux for only 2 hours (S:1~.78%, P:5.57%~. Softwood lignins showed 18.54-24.56% sulfur and 6.96-7.40% phosphorus uptake. Wood fiber reacted with phosphorus ~entasul~ide had 19.26% sulfur and 4.72% phosphorus. The reaction may also be conducted by melt mixing, for example at 140-150C
,~
, .
.~
- 8 ~ S
for a period of 4 hours to give products of the order of S:18.2% and P:9.95%. Preferably, the mole ratio S:P:Ar is between 0.4-2: 0.3-1:1.
Normally, when a solvent is used, once the reaction is completed, the reaction product i.e. the lignin product is precipitated by making use of an acid medium. HC1, H2SO~, H3PO4 or other compatible acids may be conveniently ussd. The product may then be purified through ultrafiltration or treated otherwise.
The lignin may be modified before or after the reaction with P4S1o: When a more insoluble product is desired, to be used as chelators for instance, the lignin product may be cross-linked.
Conveniently formaldehyde is one of the cross-linking agents which may be used: In such cases, the P-S-H groups are generally no longer shown on IR analysis, reacting with the formaldehyde in the cross-linking process.
These products may be used in numerous manners. As examples in chelation, as flame retardants, in polymer composites, in agriculture, in the making of composites. They could also be used to release minerals in soils, and to immobilize biological molecules such as enzymes and other proteinaceous materials.
EXAMPLES
The following will now serve to illustrate particular embodiments of the invention.
Eight parts by weight of a lignin derived from kraft hardwood isolated by CO2 precipitation, were dissolved in 100 parts dry pyridine and then 15 parts P4S1o was carefully added taking care of the exothermic conditions. After stirring for 15 hours (h), the mixture was refluxed for 23h. On cooliny to 9 ~ 5 about room temperature, the mixture was poured into 1500 parts H20 and acidified to pH 2 with 85% H3PO4 to precipitate the lignin product. After standing for 3h, the solid was collected by filtration, washed with water and dried: 14.20 parts of light brown lignin thiophosphate were obtained containing 19.92~ sulfur, giving a yield of 178%.
Because insoluble sulfur chemically unbound lignin had formed during the 3 hours standing, the brown solid was continuously extracted with CS2 in order to remove free, i.e.
water insoluble, chemically unbound sulfurl (about 4~ by weight of the lignin thiophosphate~.
The purified thiophosphate was dialyzed for 4 days at 22C
with a molecular weight cut off (3500 MWCO) cellulose acetate membrane against 1200 parts H2O, the water being changed each day, 13.46 parts of product were thus obtained having on analysis: C: 47~20~, H: 4.32%, P: 9.03%, S: 18.07% or S:P:Ar::
1.5:0.7:1.
For each gram of lignin 0.68 grams o~ thiophosphate were grafted on the lignin. The product had the following solubility: water: insoluble in water having neutral and acid pH i.e. pH 13: >15.8; pH 1: 0.6; acetone: 0.1 g/l.
The IR spectrum showed absorptions at 2330 weak (w) 2130 (w), 1505, 1095, 995, 740, 655 cm~l as shown in Figure 1. The relative intensity of the main bands is given in Table 1 on page 9.
On chelation the product absorbed (mmol/g~
pH Au Ag Pt Pd Hg Ca Cu Ni 2 2.5 3.4 0.7 3.0 3 4.1 4.8 0.2 0.4 2.3 0.3 11 1.7 ., , ~
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', '', - 10 - ~2a~138~7~Ei5i When NaCl is added in the presence of Cu ions about 2.05 mmol/g of copper were chelated against 0.008 mmol/g of Na, thereby demonstrating that our "lignin thiophosphate" i5 a chelator.
The chelation of the copper was compared against the chelating properties of a resin commercially available under the name "DOWEX XFS 4195"*** at pH 3, wherein with DOWEX*~* 1.9 mmol/g of Cu were collected, indicative of the relative good characteristics of applicant's chelating agent. The chelation of lead was also carried out at pH 6, the product chelating 1.8 mmol/g as compared against DIANION CR-10*** (a resin having active COOH groups) at pH 2-5 chelating 1.5 mmol/g of lead.
A thermal analysis of the product revealed the following:
NITROGEN OXYGEN
temperature eventtemperature event ( C) ( C) Example 1 580 weak exotherm 290 exotherm 480 exotherm 300 26% WL* 300 20% WL
450 45% WL 450 41% WL
700 50% WL 700 73% WL
ash 50% ash 27%
Untreated li~nin**
520 weak exotherm 320 exotherm 400 spontaneous comb.
300 20% WL 300 20% WL
450 40% WL 450 92% WL
700 84% WL 700 ~2% WL
*** a trademark ash 16% ash 8%
*WL in these thermal analys2s of product stand~ for weight 1066, a~ tabulated in Examples 1, 2 and 4~ These results are graphically illustrated in Figures 13 to 16.
In the presence of oxygen, the product obtained from Example 1 at 700C was found to yield 27% ash in compari-son to 8% with the lignin derived from kraft hardwood as defined in Example 1, line 1, which we will call "untreated lignin**" for sake of bxevity to designate in Examples 1, 2 and 4 the lignin originally used in these Examples, i.e.
untreated with P4Slo. Furthermore, the product obtained from Example 1 has two small exotherms at 290C and 480C in comparison with spontaneous combustion at 400C
for untreated lignin (see Figure 14). Even in nitrogen resistance to heat is also shown comparing the product of ~xample 1 (Figure 15~ whose ash content is 35% against 18%
for untreated lignin (Figure 16).
Thi~ is indicative of the ability of the product for use as flame retardant and/or thermoplastic additive.
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Sixteen parts of dry lignin, derived from kraft softwood, as obtained by ultrafiltration through a U.F. membrane having a molecular weight cut off (~WCO) of 20,000 and isolated by HCl precipitation, were refluxed with 200 parts dry pyridine for 30 minutes (min). P4S1o (30 parts) was added and the mixture refluxed for two days. On cooling to room temperature, it was then poured into 1500 parts IN HCl and immediately filtered to prevent precipitation of sulfur chemically unbound to lignin.
The solid was dialyzed for 3 days against dilute (2%) H3PO4 through a membrane having a MWCO of 5000, ~4.15 parts of product were obtained giving a yield of 151%, and the following on analysis: P 6.96% S: 18.54% or S:P:Ar: : 1.5:0.6:1.
The product had the following solubility: insoluble in acid and neutral pH i.e., pH 13: 8.6g/1; pH 1: 0.6g/1; acetone: 0.3 g/1.
The IR spectrum showed peaks at 2320 (w), 2130 (w), 1495, 1105, 970, 740 and 665 cm~l as shown in Figure 2, and the relative intensity o~ the main bands is given in Table 1.
On chelation the product absorbed (mmol/g) pH Au Ag Pt Pd Cu Hg La Y Er Ca 2 6.4~ 5.99 2.05 6.44 2.4 1.1 0.6 3 7.46 5.44 2.0 1.4 0.6 7 11.6 This affinity for platinum and calcium was compared respectively against commercially available resins known as:
MONIVEX* - having R~NC(S)SH as active groups, for platinum, and UNICELLEX* UR-30 having iminodiacetic acid groups, for calcium, in acid at pH below 3. These resins had about the same amount of absorbed product as in Example 2 for Pt, and * a trademark '' Ca. It ~hould be noted that there is no known resin commercially available for comparing against the chelating characteristcs of rare earth of the product a~ obtained in Example 2. Example 2 however illu6trates the ability to collect these rare earths, the affinity for palladium is also remarkable.
A thermal analysis of the product revealed the following;
NITROGEN OXYGEN
10temperature event temPeratUre event (C) (C) Example 2 320 exotherm 280 exotherm 450 exotherm 15300 21% WL 300 18% WL
450 30% WL 450 49% WL
700 45% WL 700 78~ WL
ash 55% ash 22%
Untreated Liqnin kraft so~twood*
20350 exotherm 280 exotherm 350 exotherm 300 6% WL 300 12% WL
450 30% Wh 450 60% WL
700 54% WL 700 90% wL
25ash 46% ash 10%
*as per line 1, Example 2 These results are graphically illustrated in Figures 17 to 20 in line with Figures 13 to 16 discussed in Example 1.
Sixteen parts of a dry sodium salt of a kraft so~twood lignin commercially available under the trademark: "Indulin C"
were refluxed with 200 parts dry pyridine for 30 minutes.
P4Slo (30 parts) was added and the mixture refluxed for 2 days.
After cooling to room temperature it was then poured onto 1500 parts IN HCl and immediately filtered. The solid was dialyzed against dilute (2%) H3P04 for 5 days through cellulose acetate MWCO 5000, yiPlding 22.87 parts, for a yield of 140%, the product having the following characteristics: P: 7.40%, S:
24.56% or a ratio of S:P:Ar:: 1.9:0.6:1.
The product had the following solubility: insoluble at neutral and acid pH i.e. pH 13: >7.4; pH 1: 1.0; acetone: 0.7 ` g/1.
The IR spectrum showed peaks ak 2310 (w), 2120 (w), 1500, 1110, 980, 740 and 670 cm~l as shown in Figure 3, and the relative intensity of the bands is given in Table 1.
on chelation the product absorbed (mmol/g) pH Au Ag Pt Pd Hg 2 5.10 10.22 1.78 3.97 3 9.14 0.8 7 3.4 11 2.0 The chelating properties for silver (10.2 mmol/g) are superior to the commercial resins known as IMAC-TMR (haviny active RSH groups), which claims 3.9 mmol/g and SVPD-5, (having active pyridine groups), which claims 5.0 mmol/g of silver absorption.
Twenty parts of dried wood fiber in 200 parts of pyridine ,~
was refluxed with 50 parts P4S1o. After 2 days, the mixture was poured onto dilute (2%) H3P04, as there was no evidence of sulfur formation due to all the P4S1o being chemically bound the mixture in water was stirred for 4 hours at 20C and filt~red by suction. The solid was dialyzed against 1000 parts H20 for 3 days through cellulose acetate MWCO 3500. 17.18 Parts of product were obtained, for a yield of 86% having P:4.72%, S:19.26%. Results of the IR analysis are shown in Figure 4 and Table 1.
A thsrmal analysis of the product revealed the following:
NITROGEN OXYGEN
temperature event temperature event ( C) ( C) Example 4 380 exotherm 240 exotherm 300 36% WL300 41% WL
450 45% WL450 60% WL
700 55% WL700 78% WL
ash 45% ash 22%
Wood fibers*
280 exotherm 270 spontaneous combustion 300 36% WL300 88~ WL
450 80% WL450 88% WL
700 91% WL700 88% WL
ash 9% ash 12%
* as per line 1, Example 4 These results are graphically illustrated in Figures 21 to 24.
30DISCUSSION ON TH~RMAL PROPERTIES
' ,`.
- 17 - ~2~ 5 As is easily seen from Examples 1, 2 and 4 the products obtained are thermally more stable under nitroyen and oxygen than their starting materials tuntreated lignin), showing reduced weight losses at elevated temperatures. Under oxygen as seen from Examples 1, 2 and 4 the products obtained show increased stability as compared with their starting materials.
Their ash contents of 22-27% under oxygen at 700C is indicative of flame retardency, especially the surpression of spontaneous combustion seen in wood and lignin. The treatment of the latter materials with phosphorous pentasulfide ~P4S1o) surpresses the production of volatile flammable degradation - products at elevated temperatures and thereby producing flame retardant products.
On chelation the product absorbed gold and silver as follows expressed in mmol/g:
pHAu Ag Hg 211.6 312.8 4.4 2.7 7 9.2 This compares well against amborane 345 (see Example 6). It was also found that at pH 11, through a column, Na Au (CN~2 was collected much more rapidly than with Amberlite ERA 400, all other conditions being equal.
Five parts of phosphorous pentasulfide were added to a solution of lignin as obtained in Example 1 (5 parts) in 25 parts of pyridine and then rafluxed. After 2 hours the mixture was cooled to room temperature and poured into 1500 parts of IN
H3PO4. The solid was immediately collected by suction and dialyzed 3 days against 1500 parts of dilute H3P04 then 2 days .
- 18 - ~ ~ ~
against 1500 parts of H2O through cellulose ace~ate 3500 MWCO, 6.31 parts of material were obtained for a yield of 126% and having 5.57% phosphorous and 12.78~ sulfur, IR peaks at: 2300 (w), 2100 (w), 1505, 1110, 990, 740, 645 cm~l as shown in Figure 5 and Table 1.
The product was able to collect 7.7 mmol/g of gold on chelation at pH of 7 in the presence o~ a ten-fold excess of sodium ions and 2.2 mmol/g at pH of 2.
Ten parts of phosphorous pentasulfide were added to a solution containing 5 parts of a lignin as obtained in Example 1 (5 parts) in 50 parts of pyridine. After the initial exothermic reaction has subsided, the mixture was cooled to room temperature and stirred at room temperature for 40 hours.
The mixture was then poured onto 1500 parts IN H3PO4. The solid was immediately collected by suction and dialyzed for 3 days against 1500 parts dilute H3PO4 then 2 days against 1500 parts H20 through cellulose acetate 3500 MWCO until the odour subsided, giving 5.7 parts of material, for a yield of 114%
with IR peaks at: 2300 (w), 2100 (w), 1505, 1090, 995, 835, 770, 650 cm~l, as shown in Figure 6, and the relative intensity of the main bands given in Table 1. On analysis, the material reveals the following: 11.53% S and 3.34% P.
On chelation it was found that this material (at a pH of 2) was able to chelate 9.9 mmol of gold per g of material, and 12.2 mmol/g at â pH 7 in the presence of ten times the amount of sodium chloride.
Compared against commercial gold, chelators one obtains the following:
Resin pH: Active Group: Capacity .~
;
:
- 19 ~ 76~
mmol/g Example 4 3 12.8 6 2 9.9 6 7 12.2 Amborane 345** 2 R3N-BH3 8.4 (10.0*) Amborane 345** 8 R3N-BH3 5-4 Amberlite IRA-400** 2 R3N 1.8 (cross-linked polystyrenes 8 R3N 2.2 IONAC SR-3** 0-l R2NC(S)SH 5.0*
MONIVEX** 0-2 " 4.5*
SRAFION** 0-2 " 4.5*
POLYORG XI** - RN=CR2 7.0*
* (reported) The following illustrate applicant's product superior preference and performance for gold as compared to t.he best commercial products all other conditions being equal.
Competitive Gold Chalation (pH=2) in mmol/g Applicant's products Au / Cu Au / Pt Au / Ca Au / Hg Au / Pb 4.0* 1.2 6.~* 2.7 5.7* 0.1 5.9 1.34.~* 0.7 Amberlite IRA-400**, a commercial resin 3.3* 0.6 2.0 1.7 2.5 0.0 2.5 0.~ 2.3 0.0 Amborane 345**, a commercial resin 3.1* 0.6 5.4 4.5 6.4 0.0 7.9 0.56.2* 0.2 * maximum available gold chelated.
Au Fe Applicant's product 6.0 0.0 Amerlite IRA-400 ** 2.3 - ** a trad~k - 20 ~ 3765 Amborane 345 ** 6.1 0.0 ** a trademark EXAMPL~ 7 Five parts of phosphorous pentasulfide were added to a solution containing 5 parts of a lignin as defined in Example 1 in 25 parts of pyridine and refluxed at about 110C. After 40 hours the mixture was cooled to room temperature and poured onto 1500 parts of IN H3PO4. The solid was immediately collected by suction and dialyzed for 3 days against 1500 parts of dilute H3PO4 then 2 days against 1500 parts water through cellulose acetate 3500 MWCO, giving 6.8 parts of material for a yield of 136%, and having 5.36% phosphorous and 17.11% sulfur with IR peaks at: 1505, 1090, 980, 740, 660 cm~1/ as shown in Figure 7 and the relative intensity of the main bands given in Table 1.
On chelation with gold 8.6 mmol of gold were retained per gram of the material made at pH 2, and 10.0 mmol/g at pH 7 in the presence of ten times the amount of sodium chloride.
Ten parts of phosphorous pentasulfide were added to a solution containing 5 parts o~ a lignin as defined in Example 1/ in 50 parts of pyridine and refluxed at about 110C. After 40 hours the mixture was cooled to room temperature and poured onto 1500 parts of H~O. The solid was collected by suction and dialyzed for 5 days against 1500 parts of H2O through cellulose acetate 3500 MWCO, to obtain 8.63 parts of product for a yield o~ 172%.
The material obtained has 172% the weight of the starting material and had an IR with peaks at: 2300 (w), 2100 (w), 1495, 980, 820, 735, 645 cm~1 as shown in Figure 8 with the relative intensity given in Table 1. On analysis, it contained , .. ~i~
''-'~`'' , . ' . . .
- 21 - 9~8~
8.02% phosphorous and 18.9% sulfur.
On chelation with gold it retained 10.0 mmol/g of the material at pH 2 and 5.2 mmol/g at pH 7 in the presence of ten times the amount of sodium chloride.
Five parts of phosphorous pentasulfide were added to a solution containing 5 parts of lignin as defined in Example 1 in 25 parts of pyridine and heated to 90~C. After 11 hours the mixture was cooled to room temperature and poured onto 1500 parts of IN H3PO4. The solid was immediately collected by filtration and air dried. The dried product was washed 3 times with 100 parts carbon tetrachloride to obtain 7.25 parts of product having 6.20% phosphorous and 12.50% sulfur for a yield of 145%. Their absorbance is illustrated in Figure 9.
This material (at pH 6) was able to collect 2.9 mmol/g of mercury (Hg), 2.0 mmol/g lead and 2.1 mmol/g cadmium in line with commercially available substantially insoluble resins which have claimed capacity for Hg of:3 mmol/g for IMAC-TMR, or 1 mmol/g for Spheron T-1000.
Sixteen parts of phosphorous pentasulfide and 10 parts of a lignin as defined in Example l were thoroughly mixed together and the mixture was heated at 140-150C for 4 hours. On cooling to room temperature, 100 parts water were added and the resulting solid collected by filtration and air-dried. The solid product was washed three times with 100 parts of carbon tetrachloride to remove sulfur chemically unbound to lignin and to give a material having 9.95% phosphorous and 18.2% sulfur and P:S:Ar:: 0.8:1.4:1. The IR spectrum showed peaks at 2300 (w), 1500, 1100, 98Q, 670 and 650 cm~1 as seen in Figure 10.
- 21a -This material was able to collect 6.4 mmol/g at pH 2, - 22 - ~ 5 Five parts of lignin triazine material, (made by reacting 3.6 parts of a lignin described in Example 1 with 1 part of cyanuric chloride in 20 parts aqueous dioxane at pH 9), in 70 parts pyridine were reacted with 6 parts phosphorous pentasulfide at 90C for 21 hours. The mixture was cooled to room temperature and poured onto 500 parts water. The solid was collected by suction filtration, washed with water and dried.
The dried solid product was washed three times with 100 parts carbon tetrachloride to give a material having 6.60%
phosphorous and 15.12% sulfur P:S:Ar:: 0.5:1.1:1. The IR
spectrum as seen from figure 11 showed peaks at 2300 (w), 2100 (w), 1495, ~105, 970, 735 and 650 cm~l.
Five parts of phosphorous pentasulfide and 5 parts of a lignin as defined in Example 1, in 50 parts of pyridine were heated to 180C at 60 psi in a stainless steel autoclaveO
After 2 hours, the reaction was cooled and the resulting mixture was immediately poured onto IN H3PO4. The solid product was filtered and dialyzed 3 days against 2% H3PO4 then 2 days against water through cellulose acetate (3500 MWCO) yielding 7.6 parts of material with 7.20% phosphorous and 22.21% sulfur and P:S:Ar:: 0~6:1.7:1. The IR absorbance is shown in Figure 12.
Five parts of phosphorous pentasulfide were added to a solution of lignin as obtained in Example 1 (5 parts) in 50 parts dioxane containing 5 parts triethylamine to produce a basic medium. The mixture was cooled to room temperature and ..~
.
, . ~
S
refluxed for 40 hours. It was then poured onto 1500 parts IN
H3PO4. The solid was immediately collected by filtration and dialyæed for 5 days against water through cellulose acetate 3500 MWCO giving 7.32 parts of product having 6.79% phosphorous and 24.29% sulfur with IR peaks at 2300 (w), 1500, 830 and 640 cm~l Five parts of phosphorous pentasulfide were added to a solution of 5 parts of lignin as obtained in Example 1 in 50 parts dioxane. After refluxing for 40 hours, the mixture was cooled to room temperature and poured onto 1500 parts IN H3P04 and the solid immediately collected by filtration. The solid was dialyzed for 5 days against water through cellulose acetate 3500 MWCO giving 7.97 parts of product having B.72% phosphorous and 24.33% sulfur with IR peaks at 2320 (w), 1510, 1125, 1000, 655 cm~l.
Ten parts phosphorous pentasulfide were added to 1 part of lignin as obtained in Example 1 in 50 parts pyridine and the solution refluxed for 40 hours. It was then cooled to room temperature and poured onto 1500 parts IN H3PO4 and the solid immediately collected by fi~tration. The solid was dialyzed for 3 days against IN H3P04 and 2 days against water through cellulose acetate 3500 MWCO giving 1.06 parts of product having 8.80% phosphorous and 13.39% sul~ur with IR peaks 2300 (w), 2100 (w), 1500, 1195, 1080, 980, 735, 640 cm~l.
Five parts of a lignin containing 1.75% nitrogen derived from reacting the lignin as obtained in Example 2 (20 parts) with 37% agueous formaldehyde (100 parts) and concentrated :,,r, ~ ~
' " .
. .
i., - 2~ 7~
ammonium hydroxide (200 parts) were suspended in 50 parts pyridine, 10 parts phosphorous pentasulfide were added and the mixture refluxed for 40 hours. It was then cooled to room temperature and poured onto 1500 parts IN H3PO4 and the resulting solid collected by filtration. The solid was dialyzed for 3 days against IN H3PO4 and 2 day~ against water through cellulose acetate 3500 MWC0 giving 5.70 parts of product having 3.86% phosphorous and 9.52% sulfur with IR peaks at 2300 (w), 2100 (w), 1495, 1200, 1120, 985, 735, 640 cm~1.
Five parts of a demethylated lignin derived from reacting the lignin as obtained in Example 1 (2 parts) with sodium periodate (2 parts) in 20 parts water containing 1 part sodium hydroxide were dissolved in 50 parts pyridine, 10 parts phosphorous pentasulfide were added and the solution refluxed for 40 hours. It was cooled to room temperature and poured onto 1500 parts IN H3P04 and the resulting solid isolated and purified as described in Example 16 giving 7.41 parts of product having 6.80% phosphorous and 27.39~ sulfur with IR
peaks at 2300 (w), 2100 (w), 1490, 1190, 1080, 990, 835, 735, 645 cm~1.
Having described the invention, numerous modifications will be evident to those skilled in the art without departing from the spirit of the invention, as defined in the appended claims.
PRIOR ART
Traditional ion exchange resins contain functionalities capable of exchanging their cations, as in the case of sulfonated or phosphorylatad materials, or of exchanging their anions, as in ~uaternary aminated product~. These materials are generally synthesized in granular or spherical bead form through the polymerization of ethylenically unsaturated monomers such as styrene or acrylic acid and a cross-linking agent such as divinylbenzene to render them insoluble in a particular solvent. The monomer~ may be modified to include desired functional groups prior to the polymerization of the preformed polymeric matrix and/or they may be subsequently chemically modified to achieve the desired acid or base form. The capacities o~ these materials arQ generally expre~sed in milliequivalents active protons per gram o~ cakionic resin (meq/g) or in meq/g exchangeable chloride for the anionic resins, or sometimes referred to as: (mmol/g) as it will be used in this application.
Ion exchange resins have been used extensively in the removal of metal ions from aqueous solutions for such purposes as wa~er softening, treatment of radioactive wastes, or the purification of industrial effluents ~k , ,:
containing heavy or toxic metals. These resins have also found application in the commercial isolation of metal ions such as uranium, in the purification and separation of the fourteen rare earths and yttrium for the fabrication of semi- and super- conductors, in the recovery of chromium from spent metal plating solutions and zinc and copper from waste occuring in the synthetic f iber industry, and in the industrial isolation of precious metals such as gold and platinum in mining and their purification in electronics.
The high cost and low selectivity of most commercial ion exchangsr6 have prevented their technological use in the large scale purification of metals, uranium and gold being the exceptions, even though these resins are preferred for the analytical isolation of many different metals. The need for more selectivity in the industry has led to the develop-ment of ion exchange resins which are capable of binding preferentially a certain metal ion in the pre~ence of others of the same charge. The numerous iminodiacetic acid based resins all show preference for the first row transition metals, but they are not very selective for specific metal ions. Multiple stage elution / adsorption cycles are needed to achieve separation of several metal components~ Specialty metal ion binders have been developed for metals such as copper, gold, iron, mercury, radium and uranium. Such chelators are usually manu~ac~ured from cross-linked polystyrene or cross-linked acrylate polymer backbones, which have been elaborated to contain specific metal ion binding sites. As these site3 strongly bind the particular metal ion, elution o~ such metals from these resins usually require drastic conditions to the point of complete ashing --4 ~ 876~
of the polymer.
Increasing precious metal prices make the leaching of low grade ores profitable only, if such metals can then be selectively isolated from the pregnant solutions containing a variety of other components usually in much greater amounts.
As yet, the mining industry prefers the use of coconut shell charcoal ion exchangers to that of any synthetic resin due to their selectivity for gold and silver. Coconut shell charcoal is expensive and must therefore be regenerated at an added cost. It is fragile (up to 8% is lost in every extraction cycle along with any bound gold) and has very low capacity compared with thak of the synthetic resins. However, most resins do not discriminate enough between different metal ions and, those which do are not easily freed of their gold.
THE INVENTION
Broadly stated, the invention is directed to a product comprising lignin material substantially water insoluble at neutral or acid pH having a chemically bound sulfur content of at least 9.5~ and a phosphorous content from 3.3 to 10% by weight of the lignin material, at least 50~ by weight of said sulfur and phosphorous being in the form of thiophosphate and wharein in said lignin material the mole ratio of sulfur to phosphorous S/P is at least 1.8, sulfur to aromat~c unit, S/Ar is at least 0.7 and phosphorous to aromatic unit P/Ar is from 0.3 to 0.8, wherein said Ar in said mole ratios is arbitrarily set to define an aryl propane unit having an average molecular weight of 242, said lignin material has infra-red absorption bands evidencing P=S groups in the vicinity of 730-7~0 cm~1, P-S or Ar-S groups in the vicinity of 640-670 cm~l, P~O-Ar groups in the vicinity of 1080-1110 cm~l, aromatic groups in the ,~ .
:'"' : ~
a~a ~8~765 .
vicinity of 1490-1510 cm~1, CH2-S groups in the vicinity of 820~845 cm~1, P-0-C groups in the vicinity of 965-995 cm~l, said product being substantially free from sulfur which is not chemically bound to said lignin material, said lignin material having chelating capacities for gold at p~ 2 of at least 2.2 millimoles per gram of said lignin material and wherein when said product is free from ether and other groups absorbing in the region of 1080-1110 cm~1, the sum of the intensity of the bands in the vicinity of 640-670 cm~l and 730-750 cm~1 over the intensity of the band in the vicinity of 1080-1110 cm~l is greater than l and when said product comprises ether and other groups absorbing in the region of 1080-1110 cm~l, the sum of the intensity of the bands in the vicinity of 640-670 cm~l and 730-750 cm~l over the intensity of the band in the vicinity of 1080-lllO cm~l less the intensity in said region by said ether and said other groups absorbing in the region 1080-1110 cm~l, is greater than 1.
The invention is also directed to a method of making the above product which comprises: heating under anhydrous conditions a product containing lignin material with at least a molar equivalent ratio of phosphorous pentasulfide (P4S1o) to lignin of said lignin material, said lignin being arbitrarily set to define an aryl propana unit to obtain as a reaction product a lignin material having chemically bound a sulfur ~ontent greater than 9.5% and a phosphorous content from 3.3 to 10%, wherein the mole ratio S/P is at least 1.8 that comprises one of the following steps:
a) collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below to avoid a reaction, inherent to said reaction - ~b - ~ ~87~S
product, producing unbound sulPur, and then rapidly contacting said ~uenched reaction product with water haviny acidic pH, to precipitate out the lignin material chemically bound to sulfur and phosphorous and to leave in said water having acidic pH, said unbound sulfur, the ; reactants producing said unbound sulfur and the excess amount of phosphorous pentasulfide forming an acqueous solution with said acidic water, and rapidly filtering said ?aqueous solution to collect the precipitate of the lignin material chemically bound to sulfur and phosphorous substantially free from said chemically unbound sulfur, b) once said reaction product is obtained, collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below, then contacting said quenched reaction product with water having acidic p~ to precipita-te out the lignin material chemically bound to sulfur and phosphorous and some of the unbound sulfur and filtering said aqueous solution to collect the precipitate o~ the lignin material chemically bound to sulfur and phosphorous and the pxecipitate of unbound sul~ur, and further washing with a solvent dissolving said unbound sulfur while maintaining insoluble said lignin ma~erial chemically bound to sulfur and phosphorous to obtain said lignin material chemically bound to sulfur and phosphorous substantially free from said unbound sulfur, c) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, the amounts of P4Slo in said molar equivalent ratio being no greater than that required to react with the cellulose ~ ~ d ,". ~' ' ' ~ ',,, ' ' ':
- 'Ic ~B~Ç;5 fraction of said lignocellulose, once said reaction product is obtained cooling said reaction product said lignin material chemically bound to sulfur and phosphorous substantially free from any major amount of chemically unbound sulfur, the excess of said molar ratio unreacted with the lignin having reacted with the cellulose fraction, d) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, said molar equivalent ratio being greater than that required to react with the cellulose fraction of said lignocellulose and carrying out the method with one of steps a) and b).
By lignin containing materials is meant a product which is 100% lignin or which contains as substrate a lignin, or if desired, other additives and lignin, or chemically modified lignin such as those having other compatible functional groups, i.e. not susceptible to react with P4S1o/ nor lnterfering with the aims of this invention: that is, partaking in the reaction to produce the functional groups that are desired e.g. P-S, ; 20 P=S, C-S, O-P and not to hinder the reaction to produce them:for example, lignin sulfonate or other functional groups as lignin triazines, Lignin -C=O, lignin - COOH, lignin -CH2-NH2.
Other typical examples are products derived from hard- or soft-wood and including wood fibers themselves. The lignin used has generally a molecular weight greater than 500.
The product is cross-linkable if one desires, with cross-linking agent such as formaldehyde and may be cross-linked with other cross-linking agents that are compatible with the functional groups of the product, such as di-halogenated reagents, bis-epoxides and other known compatible cross-linking .~
,. ~v - 5 - ~8B765 agents.
DRAWINGS
In the drawings which illustrates particular embodiments of the invention.
Figure l to 12 represent IR spectra of the products obtained form Example 1 to 12 respectively, wherein the abscissa represents the frequency from 400 to 4000 cm~l as expressed in the Figures and the ordinate represents relative absorbance.
; '~
' 76~;
Figure 13 to 24 represent the i~otherm obtained from Examples 1, 2 and 4 respectively wherein:
Figure 13 is the isotherm from Example 1 in 0.
Figure 14 is same a~ in Figure 13 with untreated lignin.
Figure 15 is the isothem from Example 1 in N.
Figur~ 16 is same as in Figure 15 wikh untreated lignin.
Figure 17 is the isothem from Example 2 in 0.
Figure 18 is ~ame as in Figure 17 with untreated lignin.
Figure 19 is the isothem from Example 2 with N.
Figure 20 is the same as in Figure 19 with untreated lignin.
Figure 21 is the isothem from Example ~ in 0.
Figure 22 is same a~ in Figure 21 with untreated lignin.
Figure 23 i~ the i~othem from Example 4 in N.
Figure 24 is the same as in Figure 23 with untrsated lignin, and wherein the abscissa represents the temperature in Centigrade and the ordinate for the curves TG~ (thermo gravimetic analysi~) represents %
weight loss of the sample being analy~ed versus temperture T, and the curves related to differential thermal analysis (DTA) or dT/T indicative of the heat content or enthalpy of the product being analyzed by the relation dT, wherein dT is the difference in temperature against a standard versus a given temperture T in oxygen (0) or nitrogen (N).
'''''"'' ~387~S
THE PREFERRED WAYS OF CARRYING OUT T~E INVENTION
One of the preferred ways o~ carrying out the invention consists in diesolving lignin in a suitable solvent and then adding phosphorus pentasulfide taking care of the exothermic reaction, and then refluxing the reaction mixture.
Preferably the molar ratios of lignin to P4Slo range from 1:1 to 1:10 and most preferably 1:1 to 1:2.
Amongst preferred solvents are dioxane, and pyridine.
Other solvents dissolving lignin and compatible with the reactants, may al80 be used, if desired: for instance, dimethylsulfoxide, dimethylformamide, tetrahydrofuran.
AqueouG media should be avoided, as they tend to hydrolyze the P4slo~
The reaction time and tempQrature determines the amount of P-S addition but should be at least 2 hours at room temperature or above~ Pressure may be used if desired.
Prefexably, the temperakure ranges between 20 to 180C and most preferably in the vicinity of 110C.
For instance, new materials with sulfur contents in the range 17.11-18.90~ and phosphorus contents 5.36-9.03% are easily attainable by reacting lignin derived from hardwood with phosphorus pentasulfide in pyridine at elevated temperatures for periods of the order of 40 hours. Lowex incorporations are attainable at room tempera~ure in the order of (S:11.5il.5%, P:303+2.5~) or with reactions at reflux for only 2 hours (S:1~.78%, P:5.57%~. Softwood lignins showed 18.54-24.56% sulfur and 6.96-7.40% phosphorus uptake. Wood fiber reacted with phosphorus ~entasul~ide had 19.26% sulfur and 4.72% phosphorus. The reaction may also be conducted by melt mixing, for example at 140-150C
,~
, .
.~
- 8 ~ S
for a period of 4 hours to give products of the order of S:18.2% and P:9.95%. Preferably, the mole ratio S:P:Ar is between 0.4-2: 0.3-1:1.
Normally, when a solvent is used, once the reaction is completed, the reaction product i.e. the lignin product is precipitated by making use of an acid medium. HC1, H2SO~, H3PO4 or other compatible acids may be conveniently ussd. The product may then be purified through ultrafiltration or treated otherwise.
The lignin may be modified before or after the reaction with P4S1o: When a more insoluble product is desired, to be used as chelators for instance, the lignin product may be cross-linked.
Conveniently formaldehyde is one of the cross-linking agents which may be used: In such cases, the P-S-H groups are generally no longer shown on IR analysis, reacting with the formaldehyde in the cross-linking process.
These products may be used in numerous manners. As examples in chelation, as flame retardants, in polymer composites, in agriculture, in the making of composites. They could also be used to release minerals in soils, and to immobilize biological molecules such as enzymes and other proteinaceous materials.
EXAMPLES
The following will now serve to illustrate particular embodiments of the invention.
Eight parts by weight of a lignin derived from kraft hardwood isolated by CO2 precipitation, were dissolved in 100 parts dry pyridine and then 15 parts P4S1o was carefully added taking care of the exothermic conditions. After stirring for 15 hours (h), the mixture was refluxed for 23h. On cooliny to 9 ~ 5 about room temperature, the mixture was poured into 1500 parts H20 and acidified to pH 2 with 85% H3PO4 to precipitate the lignin product. After standing for 3h, the solid was collected by filtration, washed with water and dried: 14.20 parts of light brown lignin thiophosphate were obtained containing 19.92~ sulfur, giving a yield of 178%.
Because insoluble sulfur chemically unbound lignin had formed during the 3 hours standing, the brown solid was continuously extracted with CS2 in order to remove free, i.e.
water insoluble, chemically unbound sulfurl (about 4~ by weight of the lignin thiophosphate~.
The purified thiophosphate was dialyzed for 4 days at 22C
with a molecular weight cut off (3500 MWCO) cellulose acetate membrane against 1200 parts H2O, the water being changed each day, 13.46 parts of product were thus obtained having on analysis: C: 47~20~, H: 4.32%, P: 9.03%, S: 18.07% or S:P:Ar::
1.5:0.7:1.
For each gram of lignin 0.68 grams o~ thiophosphate were grafted on the lignin. The product had the following solubility: water: insoluble in water having neutral and acid pH i.e. pH 13: >15.8; pH 1: 0.6; acetone: 0.1 g/l.
The IR spectrum showed absorptions at 2330 weak (w) 2130 (w), 1505, 1095, 995, 740, 655 cm~l as shown in Figure 1. The relative intensity of the main bands is given in Table 1 on page 9.
On chelation the product absorbed (mmol/g~
pH Au Ag Pt Pd Hg Ca Cu Ni 2 2.5 3.4 0.7 3.0 3 4.1 4.8 0.2 0.4 2.3 0.3 11 1.7 ., , ~
' .:
', '', - 10 - ~2a~138~7~Ei5i When NaCl is added in the presence of Cu ions about 2.05 mmol/g of copper were chelated against 0.008 mmol/g of Na, thereby demonstrating that our "lignin thiophosphate" i5 a chelator.
The chelation of the copper was compared against the chelating properties of a resin commercially available under the name "DOWEX XFS 4195"*** at pH 3, wherein with DOWEX*~* 1.9 mmol/g of Cu were collected, indicative of the relative good characteristics of applicant's chelating agent. The chelation of lead was also carried out at pH 6, the product chelating 1.8 mmol/g as compared against DIANION CR-10*** (a resin having active COOH groups) at pH 2-5 chelating 1.5 mmol/g of lead.
A thermal analysis of the product revealed the following:
NITROGEN OXYGEN
temperature eventtemperature event ( C) ( C) Example 1 580 weak exotherm 290 exotherm 480 exotherm 300 26% WL* 300 20% WL
450 45% WL 450 41% WL
700 50% WL 700 73% WL
ash 50% ash 27%
Untreated li~nin**
520 weak exotherm 320 exotherm 400 spontaneous comb.
300 20% WL 300 20% WL
450 40% WL 450 92% WL
700 84% WL 700 ~2% WL
*** a trademark ash 16% ash 8%
*WL in these thermal analys2s of product stand~ for weight 1066, a~ tabulated in Examples 1, 2 and 4~ These results are graphically illustrated in Figures 13 to 16.
In the presence of oxygen, the product obtained from Example 1 at 700C was found to yield 27% ash in compari-son to 8% with the lignin derived from kraft hardwood as defined in Example 1, line 1, which we will call "untreated lignin**" for sake of bxevity to designate in Examples 1, 2 and 4 the lignin originally used in these Examples, i.e.
untreated with P4Slo. Furthermore, the product obtained from Example 1 has two small exotherms at 290C and 480C in comparison with spontaneous combustion at 400C
for untreated lignin (see Figure 14). Even in nitrogen resistance to heat is also shown comparing the product of ~xample 1 (Figure 15~ whose ash content is 35% against 18%
for untreated lignin (Figure 16).
Thi~ is indicative of the ability of the product for use as flame retardant and/or thermoplastic additive.
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Sixteen parts of dry lignin, derived from kraft softwood, as obtained by ultrafiltration through a U.F. membrane having a molecular weight cut off (~WCO) of 20,000 and isolated by HCl precipitation, were refluxed with 200 parts dry pyridine for 30 minutes (min). P4S1o (30 parts) was added and the mixture refluxed for two days. On cooling to room temperature, it was then poured into 1500 parts IN HCl and immediately filtered to prevent precipitation of sulfur chemically unbound to lignin.
The solid was dialyzed for 3 days against dilute (2%) H3PO4 through a membrane having a MWCO of 5000, ~4.15 parts of product were obtained giving a yield of 151%, and the following on analysis: P 6.96% S: 18.54% or S:P:Ar: : 1.5:0.6:1.
The product had the following solubility: insoluble in acid and neutral pH i.e., pH 13: 8.6g/1; pH 1: 0.6g/1; acetone: 0.3 g/1.
The IR spectrum showed peaks at 2320 (w), 2130 (w), 1495, 1105, 970, 740 and 665 cm~l as shown in Figure 2, and the relative intensity o~ the main bands is given in Table 1.
On chelation the product absorbed (mmol/g) pH Au Ag Pt Pd Cu Hg La Y Er Ca 2 6.4~ 5.99 2.05 6.44 2.4 1.1 0.6 3 7.46 5.44 2.0 1.4 0.6 7 11.6 This affinity for platinum and calcium was compared respectively against commercially available resins known as:
MONIVEX* - having R~NC(S)SH as active groups, for platinum, and UNICELLEX* UR-30 having iminodiacetic acid groups, for calcium, in acid at pH below 3. These resins had about the same amount of absorbed product as in Example 2 for Pt, and * a trademark '' Ca. It ~hould be noted that there is no known resin commercially available for comparing against the chelating characteristcs of rare earth of the product a~ obtained in Example 2. Example 2 however illu6trates the ability to collect these rare earths, the affinity for palladium is also remarkable.
A thermal analysis of the product revealed the following;
NITROGEN OXYGEN
10temperature event temPeratUre event (C) (C) Example 2 320 exotherm 280 exotherm 450 exotherm 15300 21% WL 300 18% WL
450 30% WL 450 49% WL
700 45% WL 700 78~ WL
ash 55% ash 22%
Untreated Liqnin kraft so~twood*
20350 exotherm 280 exotherm 350 exotherm 300 6% WL 300 12% WL
450 30% Wh 450 60% WL
700 54% WL 700 90% wL
25ash 46% ash 10%
*as per line 1, Example 2 These results are graphically illustrated in Figures 17 to 20 in line with Figures 13 to 16 discussed in Example 1.
Sixteen parts of a dry sodium salt of a kraft so~twood lignin commercially available under the trademark: "Indulin C"
were refluxed with 200 parts dry pyridine for 30 minutes.
P4Slo (30 parts) was added and the mixture refluxed for 2 days.
After cooling to room temperature it was then poured onto 1500 parts IN HCl and immediately filtered. The solid was dialyzed against dilute (2%) H3P04 for 5 days through cellulose acetate MWCO 5000, yiPlding 22.87 parts, for a yield of 140%, the product having the following characteristics: P: 7.40%, S:
24.56% or a ratio of S:P:Ar:: 1.9:0.6:1.
The product had the following solubility: insoluble at neutral and acid pH i.e. pH 13: >7.4; pH 1: 1.0; acetone: 0.7 ` g/1.
The IR spectrum showed peaks ak 2310 (w), 2120 (w), 1500, 1110, 980, 740 and 670 cm~l as shown in Figure 3, and the relative intensity of the bands is given in Table 1.
on chelation the product absorbed (mmol/g) pH Au Ag Pt Pd Hg 2 5.10 10.22 1.78 3.97 3 9.14 0.8 7 3.4 11 2.0 The chelating properties for silver (10.2 mmol/g) are superior to the commercial resins known as IMAC-TMR (haviny active RSH groups), which claims 3.9 mmol/g and SVPD-5, (having active pyridine groups), which claims 5.0 mmol/g of silver absorption.
Twenty parts of dried wood fiber in 200 parts of pyridine ,~
was refluxed with 50 parts P4S1o. After 2 days, the mixture was poured onto dilute (2%) H3P04, as there was no evidence of sulfur formation due to all the P4S1o being chemically bound the mixture in water was stirred for 4 hours at 20C and filt~red by suction. The solid was dialyzed against 1000 parts H20 for 3 days through cellulose acetate MWCO 3500. 17.18 Parts of product were obtained, for a yield of 86% having P:4.72%, S:19.26%. Results of the IR analysis are shown in Figure 4 and Table 1.
A thsrmal analysis of the product revealed the following:
NITROGEN OXYGEN
temperature event temperature event ( C) ( C) Example 4 380 exotherm 240 exotherm 300 36% WL300 41% WL
450 45% WL450 60% WL
700 55% WL700 78% WL
ash 45% ash 22%
Wood fibers*
280 exotherm 270 spontaneous combustion 300 36% WL300 88~ WL
450 80% WL450 88% WL
700 91% WL700 88% WL
ash 9% ash 12%
* as per line 1, Example 4 These results are graphically illustrated in Figures 21 to 24.
30DISCUSSION ON TH~RMAL PROPERTIES
' ,`.
- 17 - ~2~ 5 As is easily seen from Examples 1, 2 and 4 the products obtained are thermally more stable under nitroyen and oxygen than their starting materials tuntreated lignin), showing reduced weight losses at elevated temperatures. Under oxygen as seen from Examples 1, 2 and 4 the products obtained show increased stability as compared with their starting materials.
Their ash contents of 22-27% under oxygen at 700C is indicative of flame retardency, especially the surpression of spontaneous combustion seen in wood and lignin. The treatment of the latter materials with phosphorous pentasulfide ~P4S1o) surpresses the production of volatile flammable degradation - products at elevated temperatures and thereby producing flame retardant products.
On chelation the product absorbed gold and silver as follows expressed in mmol/g:
pHAu Ag Hg 211.6 312.8 4.4 2.7 7 9.2 This compares well against amborane 345 (see Example 6). It was also found that at pH 11, through a column, Na Au (CN~2 was collected much more rapidly than with Amberlite ERA 400, all other conditions being equal.
Five parts of phosphorous pentasulfide were added to a solution of lignin as obtained in Example 1 (5 parts) in 25 parts of pyridine and then rafluxed. After 2 hours the mixture was cooled to room temperature and poured into 1500 parts of IN
H3PO4. The solid was immediately collected by suction and dialyzed 3 days against 1500 parts of dilute H3P04 then 2 days .
- 18 - ~ ~ ~
against 1500 parts of H2O through cellulose ace~ate 3500 MWCO, 6.31 parts of material were obtained for a yield of 126% and having 5.57% phosphorous and 12.78~ sulfur, IR peaks at: 2300 (w), 2100 (w), 1505, 1110, 990, 740, 645 cm~l as shown in Figure 5 and Table 1.
The product was able to collect 7.7 mmol/g of gold on chelation at pH of 7 in the presence o~ a ten-fold excess of sodium ions and 2.2 mmol/g at pH of 2.
Ten parts of phosphorous pentasulfide were added to a solution containing 5 parts of a lignin as obtained in Example 1 (5 parts) in 50 parts of pyridine. After the initial exothermic reaction has subsided, the mixture was cooled to room temperature and stirred at room temperature for 40 hours.
The mixture was then poured onto 1500 parts IN H3PO4. The solid was immediately collected by suction and dialyzed for 3 days against 1500 parts dilute H3PO4 then 2 days against 1500 parts H20 through cellulose acetate 3500 MWCO until the odour subsided, giving 5.7 parts of material, for a yield of 114%
with IR peaks at: 2300 (w), 2100 (w), 1505, 1090, 995, 835, 770, 650 cm~l, as shown in Figure 6, and the relative intensity of the main bands given in Table 1. On analysis, the material reveals the following: 11.53% S and 3.34% P.
On chelation it was found that this material (at a pH of 2) was able to chelate 9.9 mmol of gold per g of material, and 12.2 mmol/g at â pH 7 in the presence of ten times the amount of sodium chloride.
Compared against commercial gold, chelators one obtains the following:
Resin pH: Active Group: Capacity .~
;
:
- 19 ~ 76~
mmol/g Example 4 3 12.8 6 2 9.9 6 7 12.2 Amborane 345** 2 R3N-BH3 8.4 (10.0*) Amborane 345** 8 R3N-BH3 5-4 Amberlite IRA-400** 2 R3N 1.8 (cross-linked polystyrenes 8 R3N 2.2 IONAC SR-3** 0-l R2NC(S)SH 5.0*
MONIVEX** 0-2 " 4.5*
SRAFION** 0-2 " 4.5*
POLYORG XI** - RN=CR2 7.0*
* (reported) The following illustrate applicant's product superior preference and performance for gold as compared to t.he best commercial products all other conditions being equal.
Competitive Gold Chalation (pH=2) in mmol/g Applicant's products Au / Cu Au / Pt Au / Ca Au / Hg Au / Pb 4.0* 1.2 6.~* 2.7 5.7* 0.1 5.9 1.34.~* 0.7 Amberlite IRA-400**, a commercial resin 3.3* 0.6 2.0 1.7 2.5 0.0 2.5 0.~ 2.3 0.0 Amborane 345**, a commercial resin 3.1* 0.6 5.4 4.5 6.4 0.0 7.9 0.56.2* 0.2 * maximum available gold chelated.
Au Fe Applicant's product 6.0 0.0 Amerlite IRA-400 ** 2.3 - ** a trad~k - 20 ~ 3765 Amborane 345 ** 6.1 0.0 ** a trademark EXAMPL~ 7 Five parts of phosphorous pentasulfide were added to a solution containing 5 parts of a lignin as defined in Example 1 in 25 parts of pyridine and refluxed at about 110C. After 40 hours the mixture was cooled to room temperature and poured onto 1500 parts of IN H3PO4. The solid was immediately collected by suction and dialyzed for 3 days against 1500 parts of dilute H3PO4 then 2 days against 1500 parts water through cellulose acetate 3500 MWCO, giving 6.8 parts of material for a yield of 136%, and having 5.36% phosphorous and 17.11% sulfur with IR peaks at: 1505, 1090, 980, 740, 660 cm~1/ as shown in Figure 7 and the relative intensity of the main bands given in Table 1.
On chelation with gold 8.6 mmol of gold were retained per gram of the material made at pH 2, and 10.0 mmol/g at pH 7 in the presence of ten times the amount of sodium chloride.
Ten parts of phosphorous pentasulfide were added to a solution containing 5 parts o~ a lignin as defined in Example 1/ in 50 parts of pyridine and refluxed at about 110C. After 40 hours the mixture was cooled to room temperature and poured onto 1500 parts of H~O. The solid was collected by suction and dialyzed for 5 days against 1500 parts of H2O through cellulose acetate 3500 MWCO, to obtain 8.63 parts of product for a yield o~ 172%.
The material obtained has 172% the weight of the starting material and had an IR with peaks at: 2300 (w), 2100 (w), 1495, 980, 820, 735, 645 cm~1 as shown in Figure 8 with the relative intensity given in Table 1. On analysis, it contained , .. ~i~
''-'~`'' , . ' . . .
- 21 - 9~8~
8.02% phosphorous and 18.9% sulfur.
On chelation with gold it retained 10.0 mmol/g of the material at pH 2 and 5.2 mmol/g at pH 7 in the presence of ten times the amount of sodium chloride.
Five parts of phosphorous pentasulfide were added to a solution containing 5 parts of lignin as defined in Example 1 in 25 parts of pyridine and heated to 90~C. After 11 hours the mixture was cooled to room temperature and poured onto 1500 parts of IN H3PO4. The solid was immediately collected by filtration and air dried. The dried product was washed 3 times with 100 parts carbon tetrachloride to obtain 7.25 parts of product having 6.20% phosphorous and 12.50% sulfur for a yield of 145%. Their absorbance is illustrated in Figure 9.
This material (at pH 6) was able to collect 2.9 mmol/g of mercury (Hg), 2.0 mmol/g lead and 2.1 mmol/g cadmium in line with commercially available substantially insoluble resins which have claimed capacity for Hg of:3 mmol/g for IMAC-TMR, or 1 mmol/g for Spheron T-1000.
Sixteen parts of phosphorous pentasulfide and 10 parts of a lignin as defined in Example l were thoroughly mixed together and the mixture was heated at 140-150C for 4 hours. On cooling to room temperature, 100 parts water were added and the resulting solid collected by filtration and air-dried. The solid product was washed three times with 100 parts of carbon tetrachloride to remove sulfur chemically unbound to lignin and to give a material having 9.95% phosphorous and 18.2% sulfur and P:S:Ar:: 0.8:1.4:1. The IR spectrum showed peaks at 2300 (w), 1500, 1100, 98Q, 670 and 650 cm~1 as seen in Figure 10.
- 21a -This material was able to collect 6.4 mmol/g at pH 2, - 22 - ~ 5 Five parts of lignin triazine material, (made by reacting 3.6 parts of a lignin described in Example 1 with 1 part of cyanuric chloride in 20 parts aqueous dioxane at pH 9), in 70 parts pyridine were reacted with 6 parts phosphorous pentasulfide at 90C for 21 hours. The mixture was cooled to room temperature and poured onto 500 parts water. The solid was collected by suction filtration, washed with water and dried.
The dried solid product was washed three times with 100 parts carbon tetrachloride to give a material having 6.60%
phosphorous and 15.12% sulfur P:S:Ar:: 0.5:1.1:1. The IR
spectrum as seen from figure 11 showed peaks at 2300 (w), 2100 (w), 1495, ~105, 970, 735 and 650 cm~l.
Five parts of phosphorous pentasulfide and 5 parts of a lignin as defined in Example 1, in 50 parts of pyridine were heated to 180C at 60 psi in a stainless steel autoclaveO
After 2 hours, the reaction was cooled and the resulting mixture was immediately poured onto IN H3PO4. The solid product was filtered and dialyzed 3 days against 2% H3PO4 then 2 days against water through cellulose acetate (3500 MWCO) yielding 7.6 parts of material with 7.20% phosphorous and 22.21% sulfur and P:S:Ar:: 0~6:1.7:1. The IR absorbance is shown in Figure 12.
Five parts of phosphorous pentasulfide were added to a solution of lignin as obtained in Example 1 (5 parts) in 50 parts dioxane containing 5 parts triethylamine to produce a basic medium. The mixture was cooled to room temperature and ..~
.
, . ~
S
refluxed for 40 hours. It was then poured onto 1500 parts IN
H3PO4. The solid was immediately collected by filtration and dialyæed for 5 days against water through cellulose acetate 3500 MWCO giving 7.32 parts of product having 6.79% phosphorous and 24.29% sulfur with IR peaks at 2300 (w), 1500, 830 and 640 cm~l Five parts of phosphorous pentasulfide were added to a solution of 5 parts of lignin as obtained in Example 1 in 50 parts dioxane. After refluxing for 40 hours, the mixture was cooled to room temperature and poured onto 1500 parts IN H3P04 and the solid immediately collected by filtration. The solid was dialyzed for 5 days against water through cellulose acetate 3500 MWCO giving 7.97 parts of product having B.72% phosphorous and 24.33% sulfur with IR peaks at 2320 (w), 1510, 1125, 1000, 655 cm~l.
Ten parts phosphorous pentasulfide were added to 1 part of lignin as obtained in Example 1 in 50 parts pyridine and the solution refluxed for 40 hours. It was then cooled to room temperature and poured onto 1500 parts IN H3PO4 and the solid immediately collected by fi~tration. The solid was dialyzed for 3 days against IN H3P04 and 2 days against water through cellulose acetate 3500 MWCO giving 1.06 parts of product having 8.80% phosphorous and 13.39% sul~ur with IR peaks 2300 (w), 2100 (w), 1500, 1195, 1080, 980, 735, 640 cm~l.
Five parts of a lignin containing 1.75% nitrogen derived from reacting the lignin as obtained in Example 2 (20 parts) with 37% agueous formaldehyde (100 parts) and concentrated :,,r, ~ ~
' " .
. .
i., - 2~ 7~
ammonium hydroxide (200 parts) were suspended in 50 parts pyridine, 10 parts phosphorous pentasulfide were added and the mixture refluxed for 40 hours. It was then cooled to room temperature and poured onto 1500 parts IN H3PO4 and the resulting solid collected by filtration. The solid was dialyzed for 3 days against IN H3PO4 and 2 day~ against water through cellulose acetate 3500 MWC0 giving 5.70 parts of product having 3.86% phosphorous and 9.52% sulfur with IR peaks at 2300 (w), 2100 (w), 1495, 1200, 1120, 985, 735, 640 cm~1.
Five parts of a demethylated lignin derived from reacting the lignin as obtained in Example 1 (2 parts) with sodium periodate (2 parts) in 20 parts water containing 1 part sodium hydroxide were dissolved in 50 parts pyridine, 10 parts phosphorous pentasulfide were added and the solution refluxed for 40 hours. It was cooled to room temperature and poured onto 1500 parts IN H3P04 and the resulting solid isolated and purified as described in Example 16 giving 7.41 parts of product having 6.80% phosphorous and 27.39~ sulfur with IR
peaks at 2300 (w), 2100 (w), 1490, 1190, 1080, 990, 835, 735, 645 cm~1.
Having described the invention, numerous modifications will be evident to those skilled in the art without departing from the spirit of the invention, as defined in the appended claims.
Claims (29)
1. A product comprising a lignin material substantially water insoluble at neutral or acid pH having a chemically bound sulfur content of at least 9.5% and a phosphorous content from 3.3 to 10% by weight of the lignin material, at least 50% by weight of said sulfur and phosphorous being in the form of thiophosphate and wherein in said lignin material the mole ratio of sulfur to phosphorous S/P is at least 1.8, sulfur to aromatic unit, S/Ar is at least 0.7 and phosphorous to aromatic unit P/Ar is from 0.3 to 0.8, wherein said Ar in said mole ratios is arbitrarily set to define an aryl propane unit having an average molecular weight of 242, said lignin material has infra-red absorption bands evidencing P=S groups in the vicinity of 730-750 cm-1, P-S or Ar-S groups in the vicinity of 640-670 cm-1, P-O-Ar groups in the vicinity of 1080-1110 cm-1, aromatic groups in the vicinity of 1490-1510 cm-1, CH2-S groups in the vicinity of 820-845 cm-1, P-O-C groups in the vicinity of 965-995 cm-1, said product being substantially free from sulfur which is not chemically bound to said lignin material, said lignin material having chelating capacities for gold at pH
2 of at least 2.2 millimoles per gram of said lignin material and wherein when said product is free from ether and other groups absorbing in the region of 1080-1110 cm-1, the sum of the intensity of the bands in the vicinity of 640-670 cm-1 and 730-750 cm-1 over the intensity of the band in the vicinity of 1080-1110 cm-1 is greater than 1 and when said product comprises ether and other groups absorbing in the region of 1080-1110 cm-1, the sum of the intensity of the bands in the vicinity of 640-670 cm-1 and 730-750 cm-1 over the intensity of the band in the vicinity of 1080-1110 cm-1 less the intensity in said region by said ether and said other groups absorbing in the region 1080-1110 cm-1, is greater than 1.
2. The product as defined in claim 1 wherein said S/Ar ratio is from 0.7 to 2 and said capacity for gold is from 5.5 to 12.8 at pH from about 2 to about 3.
2. The product as defined in claim 1 wherein said S/Ar ratio is from 0.7 to 2 and said capacity for gold is from 5.5 to 12.8 at pH from about 2 to about 3.
3. The product as defined in claim 1 having S contents from 11%
to 27.39%.
to 27.39%.
4. The product as defined in claim 1 having a chelating capacity, at a pH of about 2 to 3, in millimoles per gram of lignin of:
4.4 to 10.22 for silver 1.78 to 2.8 for mercury 2.3 to 3.97 for copper
4.4 to 10.22 for silver 1.78 to 2.8 for mercury 2.3 to 3.97 for copper
5. The product as defined in claim 3 wherein said lignin material further includes an infra-red absorption band evidencing P-S-H groups in the vicinity of 2100 cm-1.
6. The product as defined in claim 1 wherein said lignin material is derived from hardwood, the sulfur content by weight is about 11.5?1.5%, and the mole ratio sulfur: phosphorous:Ar:
is 0.7-1.0:0.3-0.5:1.
is 0.7-1.0:0.3-0.5:1.
7. The product as defined in claim 1 wherein said lignin material is derived from hardwood wherein the sulfur content is between 17 and 19% and the phosphorous content is between 5 and 9% and the ratio S:P:Ar: is 1.1-1.5:0.5-0.8:1.
8. The product as defined in claim 1 wherein said lignin material is derived from softwood wherein the sulfur content is between 18 and 25%, phosphorous 7-8% and the ratio S:P:Ar is about 1.4-1.8:0.5-0.8:1.
9. The product as defined in claim 1 wherein said lignin material is derived from a lignin triazine product having an average of about one triazine fragment per Ar unit.
10. The product as defined in claim 1 wherein said lignin material is wood fibers.
11. The product as defined in claim 1 wherein said lignin material is chemically modified with at least one compatible functional group.
12. The product as defined in claim 11 wherein said modified lignin is a member selected from the group consisting of lignin-C=O, lignin-COOH and lignin-CH2NH2.
13. The product as defined in claim 1 comprising lignin and cellulose.
14. The product as defined in claim 1 having an IR spectrum substantially as shown in Figure 4.
15. A method of making the product of claim l which comprises: heating under anhydrous conditions a product containing lignin material with at least a molar equivalent ratio of phosphorous pentasulfide (P4S10) to lignin of said lignin material, said lignin being arbitrarily set to define an aryl propane unit to obtain as a reaction product a lignin material having chemically bound a sulfur content greater than 9.5% and a phosphorous content from 3.3 to 10%, wherein the mole ratio S/P is at least 1.8 that comprises one of the following steps:
a) collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below to avoid a reaction, inherent to said reaction product, producing unbound sulfur, and then rapidly contacting said quenched reaction product with water having acidic pH, to precipitate out the lignin material chemically bound to sulfur and phosphorous and to leave in said water having acidic pH, said unbound sulfur, the reactants producing said unbound sulfur and the excess amount of phosphorous pentasulfide forming an acqueous solution with said acidic water, and rapidly filtering said aqueous solution to collect the precipitate of the lignin material chemically bound to sulfur and phosphorous substantially free from said chemically unbound sulfur, b) once said reaction product is obtained, collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below, then contacting said quenched reaction product with water having acidic pH to precipitate out the lignin material chemically bound to sulfur and phosphorous and some of the unbound sulfur and filtering said aqueous solution to collect the precipitate of the lignin material chemically bound to sulfur and phosphorous and the precipitate of unbound sulfur, and further washing with a solvent dissolving said unbound sulfur while maintaining insoluble said lignin material chemically bound to sulfur and phosphorous to obtain said lignin material chemically bound to sulfur and phosphorous substantially free from said unbound sulfur, c) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, the amounts of P4S10 in said molar equivalent ratio being no greater than that required to react with the cellulose fraction of said lignocellulose, once said reaction product is obtained cooling said reaction product said lignin material chemically bound to sulfur and phosphorous substantially free from any major amount of chemically unbound sulfur, the excess of said molar ratio unreacted with the lignin having reacted with the cellulose fraction, d) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, said molar equivalent ratio being greater than that required to react with the cellulose fraction of said lignocellulose and carrying out the method with one of steps a) and b).
a) collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below to avoid a reaction, inherent to said reaction product, producing unbound sulfur, and then rapidly contacting said quenched reaction product with water having acidic pH, to precipitate out the lignin material chemically bound to sulfur and phosphorous and to leave in said water having acidic pH, said unbound sulfur, the reactants producing said unbound sulfur and the excess amount of phosphorous pentasulfide forming an acqueous solution with said acidic water, and rapidly filtering said aqueous solution to collect the precipitate of the lignin material chemically bound to sulfur and phosphorous substantially free from said chemically unbound sulfur, b) once said reaction product is obtained, collecting said reaction product by quenching said reaction product to a temperature from about room temperature and below, then contacting said quenched reaction product with water having acidic pH to precipitate out the lignin material chemically bound to sulfur and phosphorous and some of the unbound sulfur and filtering said aqueous solution to collect the precipitate of the lignin material chemically bound to sulfur and phosphorous and the precipitate of unbound sulfur, and further washing with a solvent dissolving said unbound sulfur while maintaining insoluble said lignin material chemically bound to sulfur and phosphorous to obtain said lignin material chemically bound to sulfur and phosphorous substantially free from said unbound sulfur, c) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, the amounts of P4S10 in said molar equivalent ratio being no greater than that required to react with the cellulose fraction of said lignocellulose, once said reaction product is obtained cooling said reaction product said lignin material chemically bound to sulfur and phosphorous substantially free from any major amount of chemically unbound sulfur, the excess of said molar ratio unreacted with the lignin having reacted with the cellulose fraction, d) selecting as said product containing lignin material to be reacted with said phosphorous pentasulfide, a lignocellulose product, said molar equivalent ratio being greater than that required to react with the cellulose fraction of said lignocellulose and carrying out the method with one of steps a) and b).
16. The method as defined in claim 15 wherein step a) is selected.
17. The method as defined in claim 15 wherein step b) is selected.
18. The method as defined in claim 15 wherein step c) is selected.
19. The method as defined in claim 15 wherein step d) is selected.
20. The method as defined in claim 15 wherein from 1 to 2 molar equivalents of said phosphorous pentasulfide are heated with said lignin material.
21. The method as defined in claim 15 wherein the product containing lignin material is heated with one to two molar equivalents of phosphorous pentasulfide per mole of said lignin containing material, in an anhydrous solvent that is soluble or miscible with water.
22. The method as defined in claim 21 wherein said product containing lignin material is dissolved in pyridine, the phosphorous pentasulfide is then gradually added to said product containing lignin material dissolved in the pyridine so as to control the exothermic reaction, and thereafter reflux is conducted until said chemically bound sulfur is greater than 9.5% and phosphorous is greater than 3.3% by weight of lignin.
23. The method as defined in claim 21 wherein said product containing lignin material is dissolved in at least one anhydrous solvent selected from the group consisting of pyridine and dioxane, said phosphorous pentasulfide being gradually added to said product containing lignin material dissolved in said at least one solvent, so as to control the exothermic reaction and then reflux is conducted.
24. The method as defined in claim 23 wherein the weight ratio of lignin to phosphorous pentasulfide to solvent is 1%
lignin: from 1% and up to 10% phosphorous pentasulfide:10?20%
solvent.
lignin: from 1% and up to 10% phosphorous pentasulfide:10?20%
solvent.
25. The method as defined in claim 23 wherein the weight ratio of lignin to phosphorous pentasulfide to solvent is 1%
lignin:from 1% to 2% phosphorous pentasulfide:10?20% solvent.
lignin:from 1% to 2% phosphorous pentasulfide:10?20% solvent.
26. The method as defined in claim 15 wherein said product containing lignin material is melted with phosphorous pentasulfide.
27. The method as defined in claim 15 which further includes dialyzing said precipitate of the lignin material chemically bound to sulfur and phosphorous free from major amount of the free sulfur.
28. The method as defined in claim 15 wherein lignocellulose is used, with an excess molar equivalent ratio of phosphorous pentasulfide, said excess being bound to the cellulose portion of said lignocellulose.
29. A method for removal of metal ions from aqueous solution containing metal ions, comprising contacting said solution with the product of one of the claims selected from claim 1 to 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000553716A CA1288765C (en) | 1987-12-07 | 1987-12-07 | Lignin having sulfur and phosphorus groups |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000553716A CA1288765C (en) | 1987-12-07 | 1987-12-07 | Lignin having sulfur and phosphorus groups |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1288765C true CA1288765C (en) | 1991-09-10 |
Family
ID=32932201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000553716A Expired - Fee Related CA1288765C (en) | 1987-12-07 | 1987-12-07 | Lignin having sulfur and phosphorus groups |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1288765C (en) |
-
1987
- 1987-12-07 CA CA000553716A patent/CA1288765C/en not_active Expired - Fee Related
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