LIGNIN ESTERS OF
Mono- and Dibasic Aliphatic Acids H.F. LEWIS, F. E. BRAUNS, AND M. A. BUCHANAN The Institute of Paper Chemistry, Appleton, Wis.
E. B. BROOKBANK
The preparation, methods of purification, and physical properties are described of a large number of alSphatic monobasic esters of alkali hardwood lignin, from the acetyl through the stearoyl, and also of the dibasic esters of succinic, adipic, suberic, and azelaic acids. In general, the penta esters are formed with the lower acids, the tetra esters with the acids of medium molecular weights, and the tri esters with the higher acids such as palmitic and etearic acids. As a rule, the melting points of the products decrease with increasing chain length of the acid group as the products become more waxlike. All the eaters of alkali hardwood lignin are quite soluble in acetone, chloroform, dioxane, and ethyl acetate. Solubility in methanol and ethanol decrease6 with increasing chain length of the fatty acid, whereas the solubility in ether and petroleum ether increases with increasing chain length. Esters of benzoic acid and p-toluenesulfonic acid have also been prepared, purified, and studied. One ester (the stearate) has proved to be an excellent mold lubricant for wood plastics. It is also soluble in drying and semidrying oils, and has been successfully incorporated in ink and paint formulations.
The Mead Corporation, Chillicothe, Ohio
CYLATION of lignin and lignin derivatives has been used for some time as a means for determining the presence of hydroxyl groups in lignin and for their estimations. Thus, Willstiitter lignins of various sources have been acetylated by Pringsheim and Magnus ( l b ) , Heuser and Ackermann ( I I ) , and Fuchs and Horn (9). Freudenberg lignin from spruce and beech was acetylated by Freudenberg and co-workers (6),and Brauns and Hibbert (3) acetylated partially methylated Willstiitter and Freudenberg lignin. Freudenberg and Hem (7) reacted Freudenberg lignin with toluenesulfonyl chloride. All these lignin esters are as insoluble as the original materials from which they were prepared. Alkali lignin prepared from corncobs was acetylated by Phillips (13); that obtained from winter rye straw was benroylated by Beckmann, Liesche, and Lehmann (I); and Marshall, Brauns, and Hibbert (IB) acetylated alkali lignin from spruce. These acetylated.dkali lignins are soluble in organic solvents. Lignin derivatives, such as methruiol, glycol, and phenol lignins, have been acylated to acetyl, benzoyl, pbromobenroyl, p-nitrobenroyl, and p-toluenesulfonyl lignin eaters (a), which are also soluble in organic solvents such as dioxane, pyridine, and acetone. A lignin of comparatively high purity (Meadol) is now available on the market (14). It is prepared from a soda black liquor from hardwood cooks. The crude black liquor is evaporated to a specific gravity of 1.1 and then contains 19-20 per cent total solids, of which about 60 per cent is organic matter and the remainder is soda ash. A portion of the lignin is precipitated
A
from this solution by passing carbon dioxide obtained from flue gases into the solution until a pH of 8.5-8.6 is reached. Thie flue gas is obtained from coke burned in a Spencer boiler and cooled to 25-30" C. by means of two Struthers-Web gas coolers in series. After cooling, the gas, which averages 15 to 18 per cent carbon dioxide, is pawed through the black liquor in a tank, operating at approximately 5 pounds per square inch positive pressure, which greatly inarema the rate of carbon dioxide adsorption. During the carbonation cycle the black liquor is continuously recirculated by means of a pump, and is sprayed into the gas space in the upper third of the tank. The Mead01 separates in the form of an extremely h e precipitate which i$ coagulated by heating to 90" C. and immediately cooling to 40'. The lignin is then filtered on an acidproof Oliver vacuum filter, and thoroughly washed with water until the wash water has a light straw color and then with dilute sulfuric acid to reduce the ash content. The filtrate is returned to the pulp mill for recovery of soda ash, and the wash water and acid are discarded. The lignin is dried on a double-drum dryer. It is powdered and has a moisture content between 2 and 4 per cent and an ash content of 0.5 per cent. Its methoxyl content of 21.5 per cent agrees with that usually found for lignins from hardwood (IO). The carbon content of 64.35 per cent and the hydrogen content of 5.93 are also within the range usually found for hardwood lignins. Meadol is soluble in pyridine and partially soluble in dioxane, acetone, and alcohol; it is insoluble or only slightly soluble in ether and petroleum ether. It is thermoplastic, with a melting point of 230" C. Lignin itself is a poor material for plastics, even in combination with other plastic bases. This may be because of the presence of various types of hydroxyl groups which make it a relatively hydrophilic compound. Although in the condensation of lignin with formaldehyde, furfural, or other compounds the phenolic hydroxyl groups in the lignin may be covered, there still remain aliphatic (alcoholic) hydroxyl groups which will affect the water resistance of plastics made from it. Covering these hydroxyl groups by acylation should make the lignin less hydrophilic and, by using higher fatty acids, even water repellent. Because Meadol is now available in large quantities and bec a w it can be considered a hardwood lignin of relatively high purity, a series of Meadol esters have been prepared and their physical properties determined. In general, the esters are prepared by the dropwise addition of 5.5 moles of wid chloride to a solution of 1 mole of Meadol (molecular weight 860), previously dried in a vacuum desiccator over sodium hydroxide, in dry pyridine with vigorous stirring at room temperature. The addition requires 3C-00 minutes. The temperature is increased to approximately 65-75' C. and kept at that point, with continuous stirring, for 2 hours. The mixture is then poured into 1.5-2 liters of ice water with vigorous stirring, whereby the
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INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 35, No. 10
was sticky, It was a dark brown crumbly mass which, on drying, fused together to form a hard cake. When its solution in benzene was dropped into low-boiling petroleum ether, i t was preNo. C Yield of .\lettioxyl in PuriNo. of Atonis Purified fied Ester. Acid Theoretical Meltikig cipitated as a fine brown powder; when the Acyl Group in Acids Ester. % 70 Groups Methoryl, % Point, C. centrifuged product was dried, it partly fused Acetyl 2 98 17.2 5 197-204 and became hard and almost black. 3 96 16.3 5 11 67 .. 34 Propionyl 183-193 Butyryl 4 96 16.2 4 16.3 124-129 Lauroyl Meadol, which separated as a sticky 4 92 16.1 Ieobutvryl 4 16.3 152-162 15.6 140-155 product on pouring the reaction mixture into 15.2 4 Valeryl 6 94 14.8 5 Isovaler yl 5 96 14.5 130-140 ice water, was purified by dropping its solution Caproyl 6 96 14.1 5 13.8 135-140 6 90 14.8 4 Isocaproyl 14.9 130-145 in a mixture of acetone and dioxane into water, Heptoyl 7 89 14.3 4 14.2 120-135 Decanoyl 10 40 12.5 4 12.6 80-95 followed by a precipitation of its ether sohUndecanoyl 11 78 12.5 4 12.1 80-110 tion into methanol. Lauroyl 12 54 11.6 4 11.5 60-85 Tridecanoyl Meadol was isolated from the 11.3 Tridecanoyl 13 91 10.5 10.1 65-70 reaction mixture by distilling off the excess pyri100-108 Myristoyl 14 64 11.2 4 10.9 Palrnitoyl 15 46 11.4 3 11.8 90-105 dine and dissolving the residue in ether. The Stearoyl 16 66 11.4 3 11.2 i 40-1 80 Oleoyl 16 60 8.5 6 8.5 130-140 pyridine hydrochloride was centrifuged off the solution; it was washed twice with a saturated calcium chloride solution containing 10 per cent of hydrochloric acid, with a neutral ltcylated product separates and is filtered. If a part of the pyrisaturated calcium chloride solution, and finally with a SUEdine is to be recovered, the mixture is distilled under reduced pension of calcium carbonate in saturated calcium chloride. pressure and the residue extracted with ice water to remove the The ether solution was dried with calcium chloride and the ether pyridine hydrochloride. The isolated crude products are then distilled off, leaving the tridecanoyl Meadol as a hard waxy purified as described under the individual compounds. product. Myristoyl and palmitoyl Meadol separated ELT oils when the reaction mixture was Doured into ice water: after treatment with ESTERS OF MONOBASIC ALIPHATIC ACIDS water in a ball mill, the oils became solid.' They were filtered, Acetyl and propionyl Meadol were prepared by the action washed with water, and dried. Each of these esters was purified of acetic anhydride or propionyl chloride and pyridine on by dropping its solution in ether into absolute methanol, followed Meadol. For purification, 5 grams of the dry crude acylated by precipitation of the dioxane solution of the methanol-insoluble Meadol were dissolved in 40 cc. of dioxane and precipitated by product into water. dropping the dioxane solution into vigorously stirred ether. The Stearoyl Meadol was prepared and purified by the method used product was washed twice with fresh ether and once each with for tridecanoyl Meadol, except that the ether solution was washed high-boiling and with low-boiling petroleum ether. The product with sodium carbonate solution. This may have partially was dried in a desiccator over sulfuric acid. saponified the stearoyl Meadol because the methoxyl content Butyryl and isobutyryl Meadol were prepared from their agrees with that calculated for a tristearate. respective acyl chlorides. The crude products, obtained by Stearoyl Meadol was prepared on a semicommercial scale pouring the reaction mixtures into ice water and drying in a desicby vigorously stirring 40 pounds of Meadol with a solvent cator, were purified by the dropwise addition of a solution of 5 mixture consisting of 30 pounds of pyridine and 100 pounds of grams in 35 cc. of benzene into well-stirred petroleum ether. dioxane. Eighty pounds of stearoyl chloride were quickly added. Valeryl, isovaleryl, caproyl, and isocaproyl Meadol were The temperature of the reaction mixture rose to 90" C. which prepared from their corresponding acyl chlorides. The crude was sufficiently high to keep the reaction mixture fluid. After products, obtained by precipitation with water, were dried and stirring for a short time, the ester was precipitated by pouring purified by the addition of their solutions in benzene to petroleum the reaction mixture into cold water. The product was filtered Bt her. and washed with water. It was ball-milled with water to break Heptoyl Meadol was prepared by the action of 25 g r a m of up the lumps; the product was filtered and dried. The yield heptoyl chloride upon a solution of 25 grams of Meadol in 80 cc. was approximately 110 pounds. of pyridine. After the reaction was complete, 60 cc. of the Oleoyl Meadol was isolated from the reaction mixture by expyridine were distifled off in vacuo,and the residue was extracted traction with ether. The ether solution was washed twice with with water. The crude sticky product was milled for several 10 per cent hydrochloric acid, once with water, and then quickly hours in a ball mill, which gave a fine brown powder. In spite with ice-cold 5 per cent sodium hydroxide solution. As a separeof thorough washing and drying in a desiccator over sulfuric tion of the aqueous solution occurred slowly, it was saturated acid for several days, it still had a strong odor of heptoic acid. A 5-gram sample was purified by dropping its solution in 25 cc. with calcium chloride. The ether solution was dried with calcium of benzene into s mixture (1:l) of high- and low-boiling petroleum chloride and evaporated. ether (75-95O and 30-45" C., respectively). The yields, analytical data, and melting point data are given Decanoyl Meadol was prepared by the method used for in.Table I. butyryl Meadol. Because the crude product was sticky even after milling with water in a ball mill, it was dissolved in a mixture ALIPHATIC DIBASIC ACID ESTERS of acetone and dioxane and the solution was added dropwise to With monobasic fatty acids, tri-, tetra-, or penta-acyl comvigorously stirred water. It was filtered, washed with fresh pounds of Meadol are formed, but with dibasic acids the rewater, and dried. For further purification, a solution of 5 grams action is more complicated. If two hydroxyl groups in the in 25 cc. of absolute ether was centrifuged, filtered, and dropped lignin building unit are linked to two adjacent carbon atoms, as into absolute methanol, followed by a precipitation of its solution in glycol, or even if two hydroxyl groups are in the 1,3 position in acetone into water. to each other, as in 1,3-propanediol,it might be possible that one Undecanoyl Meadol was obtained by the action of 32 g r a m acyl dichloride would react with those hydroxyl groups t o form of undecanoyl chloride upon 25 grams of Meadol in 80 cc. of heterocyclic ring systems containing two oxygen atoms. pyridine. The crude product, even after milling in a ball mill, OF ALIPHATIC MONOBASIC ACID ESTERSO F TABLE I. CHARACTER~STICS HARDWOOD ALKALILIGNIE~
{t
1
INDUSTRIAL AND ENGINEERING CHEMISTRY
October, 1943
h-O-C==d
I
The formation of such ring systems also depends upon the size of x because with an increasing number of carbon atoms in the chain of the dibasic acid, the formation of such ring system would hecome more improbable. None of the structural formulas, with the exception of the hypothetical ones proposed by f i c h e (8), contains a glycol or 1,3-propanediol grouping of hydroxyl groups. On the bash of Freudenberg's structural formula (6), each lignin building stone with a C r C I skeleton contains one hydroxyl group; because these building stones am linked together from the side chain of one stone to the benzene nucleus of the next, i t is obvious that the hydroxyl groups in the lignin building unit must be quite a distance from one another. If it is assumed that, of the five hydroxyl groups present in the lignin building stone, two pairs are covered by two dibasic acyl groups and one hydroxyl group would still be free. Two such partially acylated lignin building stones could then react with a fifth acyl dichloride, with the formation of a penta-acyl di-Meadol derivative of the structure shown in formula I (Figure 1). As mentioned above, it is improbable that the hydroxyl groups in the lignin building unit are located in such a way as to favor the formation of heterocyclic ring systems. It is much more probable that one molecule of acyl dichloride would react with two hydroxyl groups of two lignin building units to form a twomembered chain. The simplest chain which can be formed in this way is that in which five acyl dichlorides have reacted with two lignin building unita to form a compound of the structurr. shown in formula I1 (Figure 1). Even for the formation of a compound of such a structure, the position of the hydroxyl groups must be stereochemically located in such a way as to allow the formation of ring systems. It is possible that, in a tridimensional molecule such as lignin, two hydroxyl groups may be in such relation to each other that ring formation may occur; however, that will happen only if the mme acid chloride molecule has a chance to react with these hydroxyl g r o u p before one has been taken by another acyl chloride molecule. It is possible, therefore, that two hydroxyl groups of a lignin building unit are combined with the same acyl group, although this seems unlikely. It is much more probable that, in the reaction between Meadol and a dibssic acid chloride, the letter combines with the most reactive hydroxyl group in ita vicinity and thus forms chain molecules of various size and unknown structure. The physical properties of the dibasic eatere of Meadol seem to support this view, because in most cases products are obtained which are insoluble or only partially soluble in any organic solvent. In some caaes it is possible t o separate the reaction products into fractions of various solubility, but even the more soluble portions are less soluble than the esters of the monobasic acids.
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The following Meadol esters of dibasic esters were prepared by using the general method with the exception that mom pyridine was used aa solvent, b e c a w mon after the addition of the acyl chloride, the reaction mixture becomes more and more vkcous. I n some cases, with the progTessive addition of the acyl chloride, the reaction mixture becomes gummy or even solid. Succinyl Meadol waa prepared from 25 grams of Meadol in 100 cc. of pyridine and 12 grams of succinyl chloride. A portion of the crude product was soluble in a mixture of dioxane and cyclohexanone (1: l), and was precipitated by pouring the solution into ether.
x A
x A
x A
x
A
x
A
OR
Adipyl Meadol I wan obtained by the addition of 29 g r a m of adipyl chloride to a solution of 26 grams of Meadol in 76 00. of pyridine. After about 60 per cent of the chloride had been added, the mixture became aolid and an additional 50 cc. of pyridine was added. The remainder of the chloride was diluted with 26 cc. of dioxane. At the end of the reaction, the product in the reaction b k formed a crumbly maas. Adipyl Meadol I1 was prepared with only half the above amount of adipyl ohloride. Suberyl Meadol was prepared by using only 2 molecule8 of suberyl chloride instead of 2.5, as calculated for a completely acylated Meadol. Azelayl Meadol was made in the same way as adipyl M d o l 11, using 25 grams of Meadol in 100 cc. of pyridine and 18 grama of azelayl chloride. The yields, analytical data, and physical characteristics of the dibasic acid esters are liated in Table 11. ESTERS OF AROMATIC ACIDS
OF.ALIPXUTICDIBAWC ACIDESTERS OF TABLE 11. CHARACTERIBTICS HARDWOOD A-LI LIGNIN Awl Group Succinyl Adipyl Suberylo .4eelsyl '1
No. C
Yield of PuriEed
Atov
Ester, %
in Aoids 4 6 8
9
Methoxyl Ratio of in Enter, Acid to % Mesdol
90
18.2
18.2
98 (crude) 68
4:2 a:2
16:s
4:i
sa
Nut yet purified and tested.
TheoretiMethowl, % 18.0 18.0
C. 196-200
16:s
ilriLiio
1.0
Melting Point,
uw-iso
Phthalyl Meadol I was obtained by the addition of 12 grams of phthalyl chloride (2 molecules) to a solution of 26 grams of Meadol in 80 cc. of pyridine. When half the chloride had been added, the mixture soon became viscous and the reaction mixture finally formed a rubberlie mass. The main portion of the pyridine wan then distilled off under reduced pressure, and a hard residue remained. Thie was milled with water in , a ball mill to a fine light brown powder. Phthalyl Meadol I1 was prepared in
1116
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 35, No. 10 DISCUSSION OF RESULTS
TABLEI 111.
SOLUBILITIES4 OF
ESTERS OF HARDWOOD ALKALILIQNIN
Assuming for the lignin building unit of Meadol (a Acyl Group Methanol Ethanol Acetone Ether Dioxane Benaene h a r d w o o d lignin) a unit molecular weight of 860, its Monobasic Acid Ester8 methoxyl content for six 1 Acetyl 1 3 3 0 3 2 0 3 Propionyl 1 1 0 3 3 3 2 0 3 methoxyl groups per buildButyryl 1 1 3 1 3 3 0 3 3 ing unit is calculated to be Isobut ryl 1 1 1 3 3 3 3 0 3 1 ValeryY 1 1 3 3 3 3 0 3 21.6 per cent. The methoxyl Isovaler yl 1 1 1 2 3 3 0 3 3 Caproyl 0 0 3 3 2 0 3 2 3 content found agrees well Isocaproyl 1 1 2 3 3 3 0 3 3 with the calculated value. 3 3 Heptoyl 0 0-1 3 3 2-3 0 3 Decanoyl 0-1 0 ).. ... 2-3 ... ... 0-1 ... On the basis of this molecuUndecanoyl 0 0 2 3 3 2-3 2-3 0-1 3 Lauroyl 0 0 3 3 2-3 3 1 3 lar weight and the presTridecanoyl 0 0 2-3 2 3 2-3 2-3 ... ence of five free hydroxyl M ristoyl 0-1 0-1 3 3 3 3 3 2-3 3 PaLlitoyl 1 1 3 3 ... ... 3 ... 3 groups per lignin building Stearoyl 0-1 0-1 3 3 ... 3 3 3 3 Oleoyl ... ... 3 3 ... 3 3 ... 2-3 unit (a),the methoxyl values for the tri-)tetra-, and pentaAliphatio Dibasic Acid Esters acyl derivatives were calcuSuccinyl ... 2 0 ... ... 64 Adipyl I 0 0-1 0 0 ... lated (Table IV). It is eviAdipyl I1 0-1 0 0 2-3 ... ... Suberyl 0-1 0-1 2 0 0 dent that the acetyl and Aselsyl 1 0-1 2 0 0 6Li propionyl Meadol esters are Aromatic Acid Esters penta-acyl derivatives. As Yhthalyl I 0 0 1-2 0-1 0 1-2 0 0 0 these compounds are inPhthalyl I1 0 0 1-2 0 0 1-2 0 0 0 Bensoyl 0 0 2 3 0 2 0 1 3 s o l u b l e in ether, whereas pTolueneacetic and propionic acids rulfonyl 0 0 1 2 0 3 0 0 0 are very soluble in this sol0 0 insoluble; 1 below 10%; 2 10-50%; 3 above 50% (very soluble). vent, they can be easily purified. With i n c r e a s i n g chain length of the acyl group, tetra-acyl derivatives the same way, from 15 grams of phthalyl chloride (2.5 molecules) are formed for the most part; in the cam of palmitoyl and stearoyl chlorides, triacyl esters are obtained. This may be and 105 cc. of pyridine. Benzoyl Meadol was prepared by the dropwise addition of 40 partially explained by sterio hindrances (6) or by the fact grams of benzoyl chloride to a solution of 50 grams of Meadol that the esters of the higher fatty acids are difficult to purify in 100 cc. of pyridine. The reaction mixture was poured into because of their high solubility in solvents such as ether and water, and the crude benzoyl Meadol was washed with water, 5 per petroleum ether; these solutions give homogeneous solutions cent sodium bicarbonate, 2 per cent acetic acid, and finally with aqueous alkali. The latter are used to remove the excess acid; because this procedure requires a long time, partial saponwater. A dried sample was purified by the addition of a solution in dioxane to anhydrous ether. ification of ester groups (especially of those combined to a phenolic p-Toluenesulfonyl Meadol was obtained under the same or enolic hydroxyl group) may take place. On the other hand, conditions, from 25 grams of Meadol in 75 cc. of pyridine and the methoxyl value of the oleoyl ester agrees well with a penta30 grams of ptoluenesulfonyl chloride. oleate if the method of purification can be considered sufficient. Whereas the Meadol benzoate is a penta ester, the p-tolueneSOLUBILITY A N D MELTING POINT sulfonate is a tetra ester (found, 8.3per cent; calculated for a tri ester, 7.3 per cent; for a tetra ester, 8.6 per cent; for a penta The solubilities of the crude products are given in Table 111. ester, 9.8 per cent). The methoxyl content also agrees well All the fatty esters of Meadol are quite soluble in acetone, chlorowith that of a tetra ester. As the benzoyl and the p-tolueneform, dioxane, and ethyl acetate, but the solubility in methanol and ethanol decreases with increasing chain length of the fatty acid; the solubility in ether and in petroleum ether increases with the chain length. TABLEIV. NUMBEROF ESTER GROUPSPER LIGNINBUILDING The solubility of the benzoyl and p-toluenesulfonyl derivatives UNIT is similar to that of the fatty acid esters; the toluenesulfonyl ester is the less soluble compound. The esters of the dibasic acid Methoxyl Content Calcd. for: No. Groups Aoyl M e 0 % groups 3 acyl 4 acyl 5 acyl nin per Un% Li Derivative Acyl Found, groups groups are, in general, only slightly soluble, probably because of the formation of complicated high molecular compounds; for this Acetyl 17.23 19.0 17.4 5 Propionyl 16.3 5 ... 17.17 16.33 mason their purification is difficult. Butyryl ... 4 16.23 16.32 15.4 The melting points of the purified esters are given in Tables I 16.1 16.32 15.4 ... 4 $y$frYl 16.24 ... 15.56 14.54 4 and 11. As would be expected of these amorphous and relatively IsovaEr yl 15.05 ... 4.5 15.56 14.54 Caproyl 14.06 ... 5 14.87 13.8 high molecular compounds, the melting points are far from being Isocaproyl 14.77 14.87 13.8 4 14.25 Heptoyl ... 4 14.23 13.1 sharp. Most of the products sinter long before they begin to Decanoyl 12.47 12.6 11.4 ... 4 melt, and the melting itself often occurs over a wide range. In 12.5 Undecanoyl 12.14 . . . 4 10.95 Lauroyl 11.6 10.51 ... 4 11.45 general, the melting points decrease with increasing chain length Tridecanoyl" (10.48) 10.1 11.3 )(! M yristoyl 11.2 12.5 10.94 9.7 of the acid group, because the products become more waxlike Palmito 1 11.4 10.27 11.8 3 ,.. 11.37 11.23 StearoyY 3 9.67 ... with the higher fatty acids. The melting points of the benzoyl, Stearoyl 11.23 9.52 4 . . . 9.67 the p-toluenesulfonyl, and the dibasic acid derivatives are conOleoyl 11.3 8.45 5 8.5 9.73 siderably higher than thoso of the fatty acid derivatives having a This product was not further puri5ed. the same number of carbon atoms. Chloroform
.
.
Petroleum Ether
Ethyl Acetate
I
I . .
-
-
-
I..
I
.
.
INDUSTRIAL AND ENGINEERING CHEMISTRY
October, 1943
sulfonyl Meadol esters BE easily purified, there seems to be no doubt 88 to their composition. As mentioned above, the Mesdol esters of the dibasic acids we mletively insoluble and for that reaaon we difficultto purify. Although in Some e(suocinyl, suberyl, snd seelsyl esters) tetra wtem Beem to be formed, the main product with 2 moles of phthalyl chloride is B tetra ester and with 2.5 moles is B pen& ester. INDUSTRIAL APPLICATIONS
A study of the industrial application of the Meadol esters was recently initiated. It hss been found that Mesdol stearate is an excellent mold lubricant for woody plastics such as redwood, hydrolysed wood, and the like. Because this product is also wluble in drying and semidrying a&, it may be suocessfully incorporated in ink and paint forrnulstions. A solution of Meadol steamte in linseed oil is buttery in eonsistonoy, RS compared with the stringy solutions obtained with drying oil vsrnishw. Thus, its use 88 e. modifier of the flow cherscteristics of ink8 is indicated. Mesdol suberate also appears to be an exoellent rain with some possibilities in the field of injection molding. Molding compounds in which various Mead01 esters have been substituted for Mead01 have shown B reduction in wster absorption of the finished molded articlees, espeoially when the higher esters are used. This would be expected from the hydrophobic nature of the acid group. Other possible applications of the vsrious esters am suggwted by their solubility and melting point behavior. By selection of the proper ester, it is now possible to utilize Meadol in many ap-
pliestions whem it could not be used otherwise. Studiea of these w s ~m currently underway, and the full picture of their potential field of application is still incomplete. LITERATURE CITED (1) Beokmann. E.,Liesohe, 0..and Lehmann. F..2.a m . Ckm., 34. 285 (1921). (2) Braune, F. E.. J . Am. Chem. Sao.. 61. 2124 (1839). (3) Brauns, F.E..and Hibbert, H.. Con. J . Raacorch. 13% 78 (1935). (4) Brauns, F.E.,Hibbert. H., and co-workera, Ibid., 13B.28.35.48, 61 (1935). (5) Fieudenberg, H.. ef d.,Cdldloaechern., 7. 73 (1926): 12. 263
\."".,. IIU11,
(6)Freudonberg, K.. "Tsnnh. Cellulo~. Lignin", p. 136. Berlin. Julius Sorinaer. 1933: "Fortmhiitte Chemie organisoher Natu&ke";p. 8. (7) Freudenberg. K.. and Hess, H., Ann.. 448, 121 (1926). (8) Fuohs, W.. Paper Trade J . . 102,No. 12. 33 (March 26, 1938); T d .Assoc. Papera, 19, 117 (1936). (9) Fuohs. W..snd Horn. 0.. Bot.. 62,2647 (1929). (IO) Hrgglund, E.,"Holzohamie". AuA. 2. p . 229. Leiprig. A k d . Verlsgspesellsohaft.1939. (11) Heuser. E., snd Aokennann. W., CeNulorecbm.. 5. 13 (1929). (12) Mamhsll, H. B.. Biauns, F. E., and Hibbert, H..Con. J. R 6 seorch. 13% 103 (1935). (la) Phillips, M.. J . Am. C h . Soc.. 49.2037 (1927). (14) Plunpuisn, M.. IND.E m . Cn~nr.,32,1399 (1940). (15) Pringsheim. H., sod Magms, H., 2. p h y s i d . Chnn.,105, 179 (1919). Parsemso before ths Divisioo of Ceilulare Chamistry at the 105th Meeting of the A u n n i c i i C B ~ X I C Socrsrr. *L Detroit. Mich. A preliminary report of this vsork was presented at the Anousl Meeting of tbs Tsahniaal Asaocir tion ol the Pulp sod Psper Induatry and sixmarod in Papar Trodc J.. 116, No. 13, 27-8 (April I. 1943).
ROYAL LABORATORY +No. 154 in the Bemlnheimer series of Alchemical and Historical Reproductions is one of e group of paintings, drawings, and engravings to ahow chemical laboratories of all sgcs in picture form. It is one of a secies in the Deutsches Museum in Munich. and rep-nts the Greater h b o rstory of the Royal Palace Pharmacy in Berlin as it war in 1798. In its earlier days, eonsider-
able alchemical experimentation was carried out in thin laboratory under the patronage of several Kings of Pruwiia. D.D. BEEOLZHZIMER 60 Emt 41et Street New York (17). N. Y
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