Chemicals from Pulping - ACS Symposium Series (ACS Publications)

Chapter 22

Chemicals from Pulping Product Generation from Pulping Residuals David E . Knox and Philip L . Robinson

Downloaded by UNIV OF ARIZONA on August 6, 2012 | http://pubs.acs.org Publication Date: December 4, 1992 | doi: 10.1021/bk-1992-0476.ch022

Westvaco Corporation, 5600 Virginia Avenue, North Charleston, SC 29411-2905

Recent advances i n producing improved materials from pulping byproducts are reviewed. Terpenes and their derivatives are examined i n flavors and fragrance and adhesive applications. Rosin derivatives of similar quality to products from nonpulping sources are now available. Derivatives of fatty acids are useful i n high-solids coatings, corrosion inhibitors, and soaps and detergents. The synthesis of these derivatives from pulping byproducts is discussed. Also, benefits provided to finished goods by the unique characteristics of these derivatives are examined.

For many centuries the softwood tree has been recognized as a renewable resource that provides a readily available source of chemicals. The constituents of softwoods which are the largest source of industrial chemicals are terpenes, rosins, fatty acids, and some tannins. Uses for these materials range from food applications to oilfield corrosion inhibitors. This wide application spectrum has enabled the industry to maintain a consistently broad market for these chemicals. This chapter considers some recent developments i n the uses of turpentine, rosin, fatty acid and tannins. The emphasis is on areas where these materials and their derivatives have shown recent benefits. The chemistry that differentiates these materials is described. A full review of Naval Stores has been published recently (1).

0097-6156/92/0476-0393$06.00/0 © 1992 American Chemical Society

In Emerging Technologies for Materials and Chemicals from Biomass; Rowell, R., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1992.

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MATERIALS AND CHEMICALS FROM BIOMASS TERPENES


Flavors and Fragrances Terpenes have classically been employed i n the production of pine oil for the soap and detergent industry. This remains the chief use of pinenes. Pinenes are C-10 structures consisting of α-pinene, 0-pinene, and dipentene; each of these structures is ultimately derived from the C-5 isoprene unit. The reaction of α-pinene with aqueous acid is known to give α-terpineol , which under appropriate conditions, can add a second water molecule to give terpin hydrate (Figure 1). Pine oil may be considered a textbook example of how terpenoid compounds are employed i n fragrance chemicals (1). Crude sulfate turpentine, a sulfur-rich byproduct of the pulping operation, contains the terpene mixture. Use of this material i n flavor and fragrance applications requires desulfurization. Desulfurization of turpentine feed sources may be performed by the use of peroxide or hypochlorite, although recent work has described the use of catalytic cobalt and molybdenum oxides for sulfur removal (2,3). This step is necessary to insure appropriate aroma characteristics for flavor and fragrance production. Subsequent distillation provides the major isomeric terpenes which include α-pinene, 0-pinene, and dipentene. Classically, 0-pinene was pyrolyzed to myrcene which is a precursor to a number of important flavor and fragrance chemicals including linalool, geraniol, and nerol (4). A n alternative route to these products has been developed from a mixture of hydrogenated a- and 0-pinenes. This method overcomes industry reliance on 0-pinene, which constitutes only about one-quarter of the cyclic terpenes in crude turpentine. Hydrogénation, oxidation, reduction of the hydroperoxy group, and thermolysis yields linalool, which under acidic rearrangement, gives nerol and geraniol. These latter alcohols may subsequently be converted to desired flavor and fragrance compounds (Figure 2). Recent literature has described the use of terpenoids as hygiene chemicals. A n application described by Colgate-Palmolive employed α-ionone i n noncariogenic mouthwashes (5). Ionones are well-known derivatives of terpenoid compounds. The use of ionones for decreasing mouth odor had previously been described with cariogenic sugar solutions (6,7). It was found that the use of α-ionone i n conjunction with zinc salts and sodium gluconate gave systems that effectively reduced tartar. The systems were also able to eliminate orally generated volatile sulfur compounds from food decay for extended periods of time. The ionone, by itself, does not cause a large decrease i n volatile sulfur compounds over time. Presumably, a suitable complex forms with the zinc salt to provide oral time release



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Chemicals from Pulping

OH

OH

PINE OIL

TERPIN HYDRATE

Figure 1. Hydrolysis of α-Pinene to Give Pine O i l and Terpin Hydrate

GERIANOL/NEROL

LINALOOL

Figure 2. Pinane-Based Flavor and Fragrance Chemicals


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MATERIALS AND CHEMICALS FROM BIOMASS


properties for the ionone. This type of complex formation of zinc salts for oral hygiene has been described for diketones (8); non-chelating species such as α-ionone should have similar characteristics with different zinc release properties due to the single ketone group. A n interesting use of terpenic compounds has been described based on the reaction of dipentene (d,l-limonene from tall oil sources) with sulfur and thionyl chloride (9) (Figure 3). Thio-terpenes are known to occur i n trace quantities i n such compounds as rose oil. In this reaction, monosulfurized and polysulfurized compounds are generated that have unique and desirable aroma enhancing characteristics. The chief monosulfurized components were trans-(-)-2,8-thiomenthylene, 6,8-thiomenthene-l-ylene, and the achiral epithiomenthane. When used i n trace quantities, these compounds enhance the aroma of a variety of personal use items including hair sprays, toiletry articles, and perfumes. Terpenoids i n Polymer Applications Although the use of terpenoid compounds i n flavor and fragrance applications offers exciting potential for different types of chemistry, a much larger use for terpenoid compounds is i n hot-melt and pressuresensitive adhesives. This area has been fairly well developed (1). In these applications, a- or 0-pinene and a variety of acyclic terpenoid compounds are cationically polymerized to give tackifiers for a variety of random and block copolymers. Cationic polymerization of α-pinene is shown i n Figure 4. The main adhesive copolymers employed i n hot-melt adhesive formulations include ethylene-vinyl acetate copolymers (EVA's) and styrene-butadienestyrene (SBS) or styrene-isoprene-styrene (SIS) based materials. In the case of block copolymers, the polyterpenes are presumably compatible with the aliphatic (butadiene or isoprene) section of the polymer. In the case of EVA's, the structures cited in the literature appear to be mostly random copolymers indicating that the tackifier is compatible with the resin as a whole. Generally, when used as tackifiers, polyterpenes are simply blended with the polymer and formed into a rod which may be extruded from a suitable apparatus such as an adhesive gun. These resins generally have very good "open time", the amount of time available for an adhesive prior to bonding to another substrate. In addition, good "set times" have been observed. This is the time it takes for the system to adhere after two substrates have been placed i n contact. More recently, the use of hydrogenated resins has been described (10). These hydrogenated resins have desired color and oxidative stability for use i n more demanding applications.



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TRANS- (-)-2. θ THIOMENTHYLENE

6. 8-THIOMENTHENE-1-YLENE

EPITHIOMENTHANE

Figure 3. Sulfur-Containing Aroma Enhancers From Limonene

Figure 4. Cationic Polymerization of a-Pinene


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The use of pinenes i n water-borne adhesives has been described recently (11). The copolymerization of α-pinene with dicyclopentadiene and styrene, followed by maleinization and subsequent neutralization, yields resins that have excellent adhesive qualities. These polymers are also described with tall oil rosin as a water-borne composition. In either of the above cases, the adhesive has a fairly low softening point of about 65°C to 75°C; this would probably need to be raised for many commercial applications. However, the fact that pinenes (and tall oil rosins) may be readily employed i n water-borne formulations indicates that these materials can play an important role as technology shifts due to environmental legislation from solvent-based systems to water-borne. In conclusion, terpenes are viable commercial products i n flavor and fragrance and tackifier resin applications. The fact that current use of these materials exceeds domestic production and turpentine importation is rising indicates the industrial importance of these products.

ROSIN A N D ITS DERIVATIVES Rosin Esters in Adhesive and Ink Applications For many years, gum rosin was obtained from the wounding of trees and wood rosin from the extraction of stumps. Procurement of rosin from both techniques is labor intensive and the wounding process for gum rosin results i n a premature loss of trees. Wood rosin has become scarcer with the harvesting of younger trees that have less resinous material i n their stumps. Although the use of the paraquat (Hercules ΡΙΝΕΧ· process) held promise for alleviating this situation, the use of this chemical has been largely abandoned due to unfavorable economics. Although gum is still the primary rosin source, both gum and wood rosins have become increasingly expensive. As a result, there has been an push to use tall oil rosin i n many applications that have previously been reserved for the wood and gum grades. Research has focused on two chief areas: the decolorization and the deodorization of tall oil rosin so that it is, i n effect, equivalent to gum or wood rosin. The use of different decolorization aids during the synthesis of rosin esters and the use of various antioxidants for maintaining color stability during processing have been developed (12-15). Deodorization may be accomplished by a number of means including masking of odors and chemical treatment. These processes are designed to give tall oil rosin the characteristics of the other rosin grades. The main rosin esters that are employed i n the industry consist of either glycerol or pentaerythritol esters. Generally, the degree of esterification with pentaerythritol is between two and four. These esters are compatible


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with the "soft" blocks of SBS and SIS copolymers and have suitable softening points for use i n hot melt and pressure sensitive applications. It is very difficult to esterify rosin due to the quaternary carboxylic acid group; therefore, very high temperatures must be employed. These temperatures, which are frequently in the range of 240°C to 260°C, lead to darker products. Decolorization during the synthesis of rosin esters is accomplished by using either phosphinic (12) or phosphorous (13) acid; these materials also act as catalysts for the esterification reaction. Color improvements for the different systems are noted i n Table I. The use of the phosphorous-containing acids resulted i n color reductions on the order of four Gardner color units.

TABLE I Color Improvement of Pentaerythritol Containing Rosin Esters with Phosphorous Containing Acids (12, 13) Sample

Initial Rosin Color

Final Ester Color

Control

4

8

H P0

4

4

4

4

3

2

H3PO3

A n alternative method for color control involves the use of disulfide resorcinols i n conjunction with phosphinic acid during esterification (14); no catalytic activity or color reduction was noted with the use of alternative acids such as para-toluene sulfonic acid. Hydrogenated rosin and its derivatives are still employed in applications where essentially water white materials are required (16). Many of the rosin esters that have been mentioned for use i n adhesives also find use i n ink applications. These esters and other derivatized products, have found use i n all four ink resin types: letterpress, lithography, flexography and gravure. A n extensive review of these areas is given i n reference 1.


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MATERIALS AND CHEMICALS FROM BIOMASS FATTY ACID DERIVATIVES A N D THEIR USES


Fatty acid derivatives are noted extensively i n the literature and have found many applications including soaps and detergents (17), coatings (18), and corrosion inhibition (19). The extensive uses of these materials i n commerce have shown their versatility i n meeting specifications for many product applications. The structures of the two fatty acid derivatives to be discussed are shown in Figure 5. Synthesis of these adducts involves either a Diels-Alder adduction of acrylic acid with linoleic acid or an ene adduction of maleic anhydride with oleic acid (20). Applications for these products have been i n the above mentioned areas of detergents, corrosion inhibitors, and coatings applications. However, the properties of the materials obtained are frequently different than those obtained from other fatty acid derivatives such as C-36 dimer acid. Each of these areas are addressed in turn. For the uses that are addressed, different purity materials are frequently required. The purity needs of the soap and detergent and the corrosion inhibitor industries are considerably different from the higher purity requirements (95%) demanded of coatings. Acrvlated Fatty Acid i n Soap and Determent Applications The C-21 dicarboxylic acid generated from the cycloaddition of linoleic and acrylic acids has been found to have several unique properties i n soap and detergent applications (21). Some of the unique properties of the systems include improved hydrotroping in detergents, formulations at higher solids, and lower p H formulations for cleansers. Hydrotroping i n detergents is defined as "the ability of a material to make a slightly soluble product more water soluble" (22). Formulations using an acrylated linoleic system have excellent compatibility with both anionic and nonionic fatty surfactants. This gives increased detergency with a lower loading of surfactant and hydrotrope. For instance, the hydrotroping capabilities of acrylated linoleic acid are demonstrated i n its ability to produce clear pine oil formulations (Figure 6). The use of an acrylated linoleic acid requires one-quarter to one-half the amount of product than competitive hydrotropes. Improved performance on a weight (and cost) basis coupled with biodegradability (by BOD and TOC), indicates that this fatty acid derivative would be a preferred product for hydrotropes i n detergent formulations.


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COOH

COOH

(CH )

χ

(CH )

y

2


401


2

(CHo) 2' x

x+y=12 CH

C

ACRYLATED LINOLEIC ACID

MALEINIZED OLEIC ACID

Figure 5. Acrylated Linoleic and Maleinized Oleic Acid

20 π

1

15

Formulation

NEODOL 91-8 4.7% C-12 LAS 7.9% Pine Oil 20.0% Variable Hydrotrope QS to 100% Water

>16%

10'

S χ

E9 Acrytated Linoleic Potassium Salt E2 Posphale Ester Potassium Salt Sodium Xylene Sulfonate ESS D'phenyl Ether Sulfonate Sodium Salt Figure 6. Hydrotrope Needed to Clear Pine Oil Formulation In Emerging Technologies for Materials and Chemicals from Biomass; Rowell, R., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1992.

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A second area where C-21 acrylated linoleic acid has shown promise is i n preparing high-solids soap solutions. Comparative data i n Figure 7 show viscosity versus solids curves for potassium oleate and C-21 acrylated linoleic acid soaps, and a blend of the two (23). In this figure, the ability of C-21 acrylated linoleic acid to maintain low viscosity at increased solids of a soap solution is demonstrated. Potassium oleate viscosity rises rapidly at about 20% solids; for a combination of 90% oleic acid and 10% C-21 acrylated linoleic acid, an analogous viscosity rise occurs at about 33% solids level. In these cases, the vertical rise i n viscosity indicates a maximum effective concentration at which these soaps could be used. With pure C-21 acrylated linoleic acid, the major increase in viscosities does not occur until about 65% solids. Formulations would still be possible at much higher solids levels. A combination of effects, including interference of liquid crystal formation (24-29) with the straight chain C-18 soaps, and the large number of diastereomeric pairs available i n a C-21 acrylated linoleic acid, are postulated as the reason for the system's fluidity to a much higher solids level. This ability to formulate to a much higher solids is significant since it is possible to make high-solids detergents which require less packaging and lower transportation and manufacturing costs. Another practical advantage of C-21 acrylated linoleic acid is the ability to make clear hard-surface cleaning formulations i n soaps and detergents. Generally, hard-surface cleaners are formulated at a p H of approximately 9. With normal straight-chain fatty acid soap cleaners, this p H is necessary to obtain solubility and to overcome liquid crystal formation that occurs closer to neutrality. With C-21 acrylated linoleic acid, the cleaning formulation may be mixed at a p H of about 7, which is less aggressive to sensitive surfaces such as wood. Again, C-21 acrylated linoleic acid can be used at lower pH's since liquid crystal formation is not occurring. Acrylated linoleic acid has been demonstrated to give superior performance in the area of hydrotroping, high-solids formulations, and low p H cleansers. The dual functionality and amorphous nature of this system make it superior to standard fatty acid soaps as well as a number of synthetic hydrotropes that are either petroleum based or contain phosphorous. Maleinized Fatty Acid i n Corrosion Inhibitor Applications A second area of fatty acid utilization, where new findings are significant, is the use of maleinized fatty acid (MFA) i n corrosion inhibitor applications. Maleinized fatty acid has received attention as a potential aqueous corrosion inhibitor i n a number of patent publications (30,31) and, more recently, as a product for use i n downwell oilfield applications (32).


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In the presence of a fatty imidazoline, maleinized fatty acid forms more tenacious films than the industrial standard 80% C-36 dimer/20% C-54 trimer acid mixes. These dimer/trimer mixes have been the workhorse products of the oilfield corrosion inhibitor industry for the last thirty years. Comparative test data is given i n Figures 8 and 9.


Minimum performance requirements are considered to be 90% protection under testing conditions. In both sweet (carbon dioxide) and sour (hydrogen sulfide) environments, maleinized fatty acids perform about seven to ten times better than commercial dimer/trimer. In sweet environments, only 200 ppm of the inhibitor is required versus a standard of about 2000 ppm for dimer/trimer. In sour environments, about 700 ppm of inhibitor is required versus a standard of nearly 5000 ppm for dimer/trimer. Although the cost of the maleinized fatty acid derivative is about two to three times that of commercial dimer/trimer products, it is still considerably more cost effective because of superior performance. Of particular interest are the data for sour wells. Domestic production requirements have necessitated the drilling of deeper wells to tap oil and gas reserves. These wells tend to have tremendous temperatures, pressures, and high levels of hydrogen sulfide. The use of maleinized fatty acid based corrosion inhibitor formulations i n these wells has been found to be particularly beneficial since greater protection is realized. The mechanism of corrosion inhibition by maleinized fatty acid is not known. Infrared analyses of films on metal coupons subjected to corrosive environments show that imides are present i n the film. Imides are formed when the maleinized fatty acid is combined with a fatty imidazoline derivative to give the final corrosion inhibitor package. The presence of this group may influence the film-forming capability and the bonding of the molecule to a metal surface. Acrylated and Maleinized Fatty Acids i n Coatings Recent work has demonstrated advantages for using either acrylated or maleinized fatty acids i n coating applications (33,34). These materials have been found to give viscosity reductions i n solvent- and water-borne alkyds when substituted for either phthalic anhydride or trimellitic anhydride. Using high-purity C-21 acrylated linoleic acid i n alkyds based on phthalic anhydride up to substitution levels of about 50% gives viscosity reductions enabling higher solids paints to be formulated. High-solids coatings are



404


% Solids Figure 7. Viscosity Versus Solids for C-21 Acrylated Linoleic Acid and Oleic Acid Potassium Salts

CONCENTRATION (PPM) Figure 8. Corrosion Inhibition of Maleinized Fatty Acid Derivatives vs. Dimer/Trimer Mixes - Sweet Wells



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becoming increasingly important as clean air regulations require the use of less solvent i n paint formulations. In Figure 10, viscosity curves for a standard phthalic anhydride, C-21 acrylated linoleic acid, and C-36 dimer acid alkyds are given. Results clearly indicate that the C-21 acrylated linoleic acid gives the desired low viscosity compared to either phthalic anhydride or dimer acid and would be preferred i n low-viscosity formulations. The reduced viscosity can presumably be attributed to the diastereomeric nature of the product. Dimer acid would theoretically have the same number of diastereomers as C-21 acrylated linoleic acid, but dimer acid can presumably undergo chain extension more readily than C-21 acrylated linoleic acid and gives systems of intermediate viscosity. This performance readily demonstrates the advantage of C-21 acrylated linoleic acid i n alkyd resins. Maleinized oleic acid has been evaluated i n water-borne coatings as a means of reducing organic cosolvent. Generally, water-borne coating systems are formulated with organic cosolvents to maintain solubility. Maleinized oleic acid is capable of reducing the amount of organic cosolvent required for solubilization. Viscosity reductions for typical alkyd paints are shown i n Figure 11. Maleinized oleic acid-containing resins show a three to fourfold decrease i n viscosity compared with a trimellitic anhydride-based system. Paint formulations containing maleinized oleic acid can be formulated into water from a solids level of about 80% versus a normal of 75% with trimellitic anhydride. Although this five percent difference may seem small, it is significant for manufacturers attempting to comply with volatile organic emissions from alkyd paints. Presumably, the aliphatic nature of the maleinized oleic acid makes less coupling solvent necessary.

TANNINS A N D THEIR DERIVATIVES There has recently been considerable interest i n the area of tannins and their derivatives. A recent book edited by Hemingway and Karchesy gives an extensive overview of work in the tannin area (35). We will briefly mention some of the latest developments i n tannin utilization. Tannins are very broadly classified as hydrolyzable or condensed, depending on the source and structure. Hydrolyzable tannins are generally based on gallic acid, and the non-hydrolyzable systems are based on flavonoids. The gallic acid is generally esterified with a sugar moiety, whereas the flavonoids are generally condensed i n a number of positions on the skeleton. A more detailed description of these condensates and their biosynthetic pathway has been given (36).


406



1000

Figure 9. Corrosion Inhibition Dimer/Timer Mixes—Sour Wells

2000

3000

4000

CONCENTRATION (PPM) of Maleinized Fatty Acid Derivatives vs.

•PA Based Resin

log viscosity'

50

55

60

65

75

60

% Solids Figure 10. Log Viscosity vs. Solids for Alkyd Resins in Mineral Spirits 90000 τ 80000 70000 60000

viscosity (cps)

50000

40000 30000 20000 10000 0 80

% Solids Figure 11. Viscosity Curves for Maleinized Oleic Acid and Trimellitate Formulations In Emerging Technologies for Materials and Chemicals from Biomass; Rowell, R., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1992.


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Condensed tannins have received considerable interest i n conjunction with the defense function i n trees (37,38). In light of this function, there has been considerable interest in the use of condensed tannins i n fungicide applications, although no commercial applications appear to have been made (39). A n interesting proposed use of proanthocyanadin has been described i n its use as an anti-radical agent for preventing tumor formation (40). This compound has shown evidence as a radical scavenger that presumably could serve this function i n humans and prevent diseases that are believed to be caused from free radical generation. This use is only speculative. In fact, some studies have suggested that oral ingestion of condensed tannins found i n vegetable sources and teas may lead to an increased risk of esophageal cancer (41). In either case, further studies on these compounds are necessary since they are obviously present i n vegetable sources and in high fiber compounds. A final note on tannins involves their use i n adhesive applications. The wattle tannin industry has developed i n South Africa and the South Pacific. These tannins have found use i n particleboard adhesives as a substitute for phenolics (42-44). A similar industry i n North America does not appear to be developing with great impetus, although the prices of phenolic compounds may drive the development of such an industry at a future date. Tannin molecules give phenolic resins special advantages such as faster cure cycles (35) (an advantage in the bonding of hardwoods); advances such as this may accelerate procurement and development of these compounds. Over the course of this century, uses for tannins, other than leather tanning, have been slow to develop on a concerted basis compared with other tree extracts such as terpenes, fatty acids, rosins, and lignins. As more emphasis is put on development of technology from biomass, this situation will undoubtedly change with a renewed emphasis on tannin chemistry.

CONCLUSIONS The use of tall oil terpenes, rosins, fatty acids, and tannins continues to play an important role in the development of many commercial products. Recent advances have enabled the use of tall oil-based products where only wood or gum derived products would have originally been acceptable. Tall oil derivatives have been shown to be especially good i n environmentallyfriendly systems such as water-borne adhesives and coatings, high solids soaps, and high-solids alkyd formulations. Continued development of new uses for terpenes, rosins, fatty acid, and tannin derivatives is expected as industries become acquainted with the ability of these materials to give excellent properties at a reasonable cost.


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MATERIALS AND CHEMICALS FROM BIOMASS ACKNOWLEDGEMENTS

We wish to thank Dr. John Alford for helping compile some of the information in this paper, Dr. Carl Bailey for his reviews and helpful comments, and Drs. Ben Ward and John Glomb for their editing and inputs. Mr. Gene Fischer has offered many helpful suggestions i n clarifying certain points for oilfield area and thanks are also extended to him. Thanks are also due to Judy Smith for her efforts i n the preparation of this chapter.


REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

Naval Stores; Zinkel, D. F.; Russell, J., Eds.; Pulp Chemicals Association: New York, Ν. Y., 1989 Casbas, F.; Duprez, D.; Ollivier, J. Appl. Catal., 1989, 50, 1, 87-97 Cabas, F.; Duprez, D.; Ollivier, J.; Rolley, R. European Patent Application 267,833; 1987 Zinkel, D. F. In Organic Chemicals from Biomass; I.S. Goldstein, Ed.; CRC Press: Boca Raton, Fla, 1980 Barth, J. U . S. Patent 4,814,163; 1989 McNamara, T. F.; Rubin, H . French Patent 2,127,005; 1971 McNamara, T. F.; Rubin, H . Canadian Patent 987,597; 1971 Eilberg, R. G.; Mazzinobile, S. German Patent 2,229,466; 1972 French Patent (to P. Robertet and Co.) 2,338,037; 1976 Vanhaeren, G . European Patent Application 271,254; 1987 Komitsky, Jr. F.; Thompson, K. L.; Evans, J. M . ; Ocampo, E.; Patel V . European Patent Applicaton 300,624; 1988 Duncan, D. P.; Cameron, T. B. U . S. Patent 4,548,746; 1985 Johnson, Jr. R. W . European Patent Application 257,622; 1987 Lampo, C. S.; Turner, W. T. U . S. Patent 4,650,607; 1987 Knoblock, G.; Martin, H . ; Patel, Α.; Graziosi, P. R. TAPPI. J., 1989, 72, 71-78 Hicks, J. P.; European Patent Application 342,808; 1989 Schwartz, A . M.; Perry, J . W.; Berch, J. Surface Active Agents and Detergents, Interscience: New York, Ν. Y., 1949, Vol. 1 and 2 Fulmer, R. W. In Fatty Acids and Their Industrial Applications; E. S. Pattison, Ed.; Marcel Dekker: New York, N.Y., 1968, 187-208. McSweeney, Ε. E.; Arlt, Jr. H . G.; Russell, J.; Tall O i l and Its Uses, Pulp Chemicals Assoc. Inc.: New York, Ν. Y., 1987, 92-93. Danzig, M . J.; O'Donnell, J. L.; Bell, E. W.; Cowan, J . C. J . A m . O i l Chem. S o c ., 1957, 34, 136-138 Ward, B. F., Jr.; Force, C. G.; Bills, A . M.; Woodward, F. E. J. A m . Oil Chem. S o c ., 1975, 52, 219



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22. Hawley's Condensed Chemical Dictionary; Sax, Ν. I. and Lewis, R., Eds.; Van-Nostrand: New York, Ν. Y . , 1987, 620. 23. Robinson, P. L. J. A m . Oil Chem. Soc., In preparation 24. Cox, J . M . and Friberg, S. E. J. Am. Oil Chem. Soc., 1981, 58, 743 25. Flaim, T. and Friber, S. E. J. Colloid Interface Science, 1984, 97, 26 26. Friber, S. E.; Flaim, T. D. In Structure/Performance Relationships i n Surfactants; M . J . Rosen, Ed.; Symposium Series, No. 253; ACS: Washington D. C., 1984, 107 27. Friberg, S. E.; Rananavare, S. B.; Osborne, D. W. J . Colloid Interface Science, 1986, 102, 487 28. Friberg, S. J. A m . Oil Chem. S o c ., 1971, 48, 578-581. 29. Bell, Α.; Birdi, K. S. In Structure/Performance Relationships i n Surfactants; Rosen, M . J., Ed.; ACS: Washington DC, 1984, 117-128 30. Kindscher, W.; Oppenlaender, K. German Patent 2,357,951; 1975 31. Desai, Ν. B. German Patent 2,651,438; 1978 32. Knox, D. E.; Fischer, E. R. U . S. Patent 4,927,669; 1990 33. Cosgrove, J. P. In Proceedings 17th Water-Borne and Higher Solids Coatings Symposium, 1990, 488-498 34. Knox, D. E. In Proceedings 17th Water-Borne and Higher Solids Coatings Symposium, 1990, 262-278 35. Chemistry and Significance of Condensed Tannins; Hemingway, R. W., Karchesy, J . J., Eds.; Plenum Press: New York, Ν. Y . , 1989 36. Lewis, N . G.; Yamamoto, E. In Chemistry and Significance of Condensed Tannins; Hemingway, R. W.; Karchesy, J . J., Eds.; Plenum Press: New York, Ν. Y . , 1989 37. Scalbert, Α.; Haslam, E. Phytochemistry, 1987 26, 3191-3195 38. Stafford, H . A . Phytochemistry, 1988 27, 1-6 39. Rao, S. S.; Rao, Κ. V. Indian J. Plant Physiol., 1986, 29, 278-280 40. Masquelier, J. U . S. Patent 4,698,360; 1987 41. Morton, J. F. In Chemistry and Significance of Condensed Tannins; Hemingway, R. W.; Karchesy, J. J., Eds.; Plenum Press: New York, Ν. Y., 1989 42. Pizzi, Α., Orovan, E., Cameron, F. A . Holz Roh-Werkst., 1988, 46, 67-71 43. Collins, J . C., Yazaki, Y . Australian Patent 569,439; 1987 44. Collins, J . C., Yazaki, Y. Australian Patent Application 81663/87; 1987 45. Collins, P. J . Australian Patent Application 50817/85; 1985 RECEIVED April 12, 1991


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