Ind. Eng. Chem. Res. 1987,26, 894-899
894
that the formation of deposita in our experiments occurs under control of oxygen diffusion, at least when small amounts of oil are used. The data in Figure 11 show that the average oxygen concentration in the film decreases with increasing film thickness and rate coefficient, k,. Although this may affect the rate of oil oxidation, lack of exact information about the initial oxidation rates, the activation energies, and the relative importance of the different oil degradation steps precludes a more thorough analysis at this point. Increasing ko or the film thickness has a more dramatic effect on the concentration of oxygen at the liquid-metal interface. The oxygen concentration in the interface decreases considerably with increasing film thickness, especially for higher values of the rate coefficient. An indication of such behavior was observed in our tests where the polished surfaces showed fewer signs of oxidation when thicker films were used, even after the oil had oxidized for long times. In such a case, it will be reasonable to expect that the differences in deposit formation, observed between polished and polished/oxidized surfaces, would be more evident when thicker films are involved, since the lower oxygen concentration at the interface will not result in considerable oxidation of the iron surface before the formation of deposits. This was exactly the case observed in our tests, as representative data illustrate in Figure 12.
Literature Cited Abramowitz, T., Stegun, T., Eds. Handbook of Mathematical Functions; Applied Mathematics Series 55; National Bureau of Standards: Washington, DC, 1964; p 299. Anderson, D. J. “Mechanisms of Engine Deposit and Wear, A Progress Report”, Presented at the Japanese Petroleum Institute Togyo, Japan, 1968. Bird. B. R.: Stewart. W. E.: Liehtfoot, E. N. Transport Phenomena; Wiley: New York, 1960; p-515. Burn, A. J.; Cecil, R.; Young, V. 0. J.Inst. Pet. 1971,57(558), 319. Cho, L. F.; Klaus, E. E. S A E Technol. Ser. 1983, 831679. Clark, D. B.; Klaus, E. E.; HNU,S. M. A S L E Trans. 1984, 84-AM3D-1. Crank, J. The Mathematics of Diffusion; Clarendon: Oxford, 1975. ’
Cvitkovic, E.; Klaus, E. E.; Lockwood, F. E. ASLE Trans. 1979, 22(4), 395. Diamond, H.; Kennedy, H. C.; Larsen, R. G. Ind. Eng. Chem. 1952, 44(8), 1834. Ebert, B. L., Ed. Chemistry of Engine Combustion Deposits; Plenum: New York, 1985. “General Motors Engineering Standards, Materials and Processes”; Revision of May 1984; Current Products Engineering, General Motors Corporation, Warren, MI. Klaus, E. E., Pennsylvania State University, University Park, personal communication, March 1986. Korcek, S.; Jensen, R. K. A S L E Trans. 1975, 75-AM-1A-1. Lahijani, J.; Lockwood, F. E.; Klaus, E. E. ASLE Trans. 1980,25(1), 25. Lauer, J. L.; Vogel, P.; Seng, G. T. Prep.-Am. Chem. SOC.Diu. Pet. Chem. 1984, 29(4), 1015. Lloyd, W. G.; Zimmerman, R. G.; Dietzler, A. J. Ind. Eng. Chem. Prod. Res. Deu. 1966, 5, 329. Lockwood, F. E.; Klaus, E. E. A S L E Trans. 1980, 24(2), 276. Lockwood, F. E.; Klaus, E. E. A S L E Trans. 1981, 25(2), 236. Mayo, R. F.; Richardson, H.; Mayorga, D. G. Prepr.-Am. Chem. SOC.,Diu. Pet. Chem. 1975, 20(1), 38. Murphy, C. K., GM Research Laboratories, Warren, MI, unpublished data, 1984. Naidu, S. K.; Klaus, E. E.; Duda, J. L. Ind. Eng. Chem. Prod. Res. Deu. 1984, 23, 613. Nepogod’ev, A. V.; Mitin, E. V.; Litvishkova, V. A. Khim. Teknol. Topliv Masel 1985, I, 17-19. Perry, T., Chilton, T., Eds. Chemical Engineers’s Handbook, 5th ed., McGraw-Hill Kogakusha LM: Tokyo, Japan, 1973. Sampson, R. J.; Shooter, D. In Oxidation and Combustion Reviews; Tipper, T., Ed.; Elsevier: New York, 1965; Vol. 1, p 223. Sheldon, R. A.; Kochi, J. K. Metal-Catalyzed Oxidations of Organic Compounds; Academic: New York, 1981. Shen, S. Y.; Klaus, E. E. A S L E Trans. 1983, 27(1), 45. Stewart, W. T.; Stuart, F. A. Advances in Petroleum Chemistry and Refining; Interscience: New York, 1963; Vol. 7, p 3. Taylor, W. F.; Wallace, T. J. Ind. Eng. Chem. Prod. Res. Deu. 1968, 7(3), 198. Taylor, W. F. IrLd. Eng. Chem. Prod. Res. Deu. 1969, 8(4), 375. Taylor, W. F. Ind. Eng. Chem. Prod. Res. Deu. 1974, 13(2), 133. Taylor, W. F.; Frankenfeld, J. W. Ind. Eng. Chem. Prod. Res. Deu. 1978, 17(1), 86. Received for review July 11, 1986 Accepted February 12, 1987
Effects of Variations in Washing on the Formaldehyde Release Properties of Durable Press Cottons? Robert M. Reinhardt* and B. A. Kottes Andrews Southern Regional Research Center, USDA, Agricultural Research Service, M i d - S o u t h Area, N e w Orleans, Louisiana 70179
Further observations have been made on the effects of washing on the formaldehyde release properties of durable press cottons. In previous papers, the authors have described findings on the effects of pH in washing and on the influence of certain finishing treatment factors on the relationship between washing and formaldehyde release. As an extension of that research, changes in the formaldehyde release properties of various durable press cottons were studied as functions of variations in the washing process. Among washing variations were water quality, detergent type, water hardness, inclusion of bleach, pH adjustment, and buffered rinses. Cotton fabrics finished with several different crosslinking agents were included in various aspects of the study with the main emphasis on fabric treated with dimethyloldihydroxyethyleneurea (DMDHEU). A review of factors that contribute to formaldehyde release also is presented. Wide-ranging studies on finish decomposition in cotton fabrics have been conducted at this Research Center for several years. A large portion of the activity in this area of research has been concerned with the phenomena of +Presented a t the Gulf Coast Textile Chemistry Conference 1986, New Orleans, March 20-21, 1986.
formaldehyde release from durable press and other chemically finished cotton textiles. During the course of this research, many observations on the effects of washing on formaldehyde release from finished cottons have been made. Some of these observations provide a scientific basis for many long held but empirical understandings of the benefits of washing. However, other findings have been
This article not subject to U.S. Copyright. Published 1987 by t h e American Chemical Society
Ind. Eng. Chem. Res., Vol. 26, No. 5, 1987 895 made which indicate that some conventional wisdom is flawed or limited in generalization and not applicable in all practical cases. The purpose of this paper is to extend our appreciation of the effects of washing finished cottons, both in the plant and in the home, and to show the influence of certain variations in washing on formaldehyde release.
Background: Formaldehyde Release The release of formaldehyde from fabrics that have been chemically finished is influenced by various factors. Several reviews of this subject are available (Achwal and Kamat, 1979; Andrews et al., 1980b; Bille, 1984; Cooke, 1983; Cooke and Weigmann, 1982; Harper, 1983; Kullman et al., 1978; Palmetto Section, 1982a; Petersen and Petri, 1985; Vail and Reinhardt, 1981; Wayland et al., 1981). Among the most important factors that determine the extent of formaldehyde release are as follows: (1)The nature of the fabric, including its fiber composition, textile structure, and preparatory processing (desizing, scouring, bleaching, dyeing, etc.). (2) The chemistry of the finishing agent applied, particularly its reactivity, stability, functionality, purity, and appropriateness for the end product (Andrew and Harper, 1980; Andrews and Reinhardt, 1985; Kim at al., 1984; North, 1977; Petersen and Pai, 1981; Vail, 1985; Vail and Pierce, 1973). (3)The catalyst or catalyst combination employed in the finishing treatment (Andrews et al., 1980b; Andrews and Reinhardt, 1982; Day and Reeves, 1983; Reeves and Day, 1983; Reeves et al., 1981,1983; Reeves and Salleh, 1984). (4) Additives present in the finishing recipe, some of which are specifically included to improve formaldehyde release properties (formaldehyde scavengers) and some of which have detrimental effects (Andrews et al., 1980a; Cashen, 1979; Hebeish et al., 1979b; Perry et al., 1980; Reinhardt and Daigle, 1984; Tomasino and Taylor, 1984; Turner and Cashen, 1981). (5) The level of finish application (Andrews and Harper, 1984;Andrew et al., 1980b; Andrew and Reinhardt, 1982). (6) Treatment conditions employed, principally the time and temperature of the curing process during which reaction between the finishing agent and the cellulose takes place (Andrews et al., 1980b; Cooke and Weigmann, 1982). (7) The presence of residues and impurities in the fabric, both prior to and after the finishing treatment (Andrews and Reinhardt, 1984; Palmetto Section, 1982b; Reinhardt, 1983). (8)Aftertreatments such as the application of top softeners, dimensional stabilization, and treatments to decrease formaldehyde release (Gregorian and Namboodri, 1984; Hebeish et al., 1979a; Hendrix and Payet, 1984; Pai, 1982; Reinhardt and Daigle, 1984; Reinhardt and Harper, 1984; Reinhardt et al., 1972; Waddle et al., 1959). (9) Storage and handling of the finished fabric between finishing and sewing or product manufacture and in the intervals between manufacture and retailing (Beck and Pasad, 1982; Jaco and Hendrix, 1982; Kaneko and Yokoyama, 1976; Reeves et al., 1981; Reid et al., 1960; Seguchi et al., 1978). (10) Washing of the finished fabric at the processing plant (usually omitted because of economic reasons) and by the consumer, either in the home or at commercial or coin laundries (Nieuwenhuis, 1982; Reid et al., 1962; Reinhardt and Andrews, 1983; Reinh&dt and Andrews, 1984; Reinhardt et al., 1981; Walters and Noel, 1984). All of these factors are interactive. The finisher must be fully cognizant of their effects in devising finishing systems and fabrics to be utilized. The consumer, although
not an active participant in the textile processing decisions, does play the dominant role in the use, care, handling, and laundering of household products and garments made from the fabrics. Washing, of course, is a means of controlling and maintaining the fabric's formaldehyde release properties, if a proper washing is conducted.
Experimental Section Fabric used was an 80 X 80 cotton printcloth, 3.2 oz/yd2, that had been desized, scoured, and bleached. The finishing agents, dimethyloldihydroxyethyleneurea (DMDHEU), methylated dimethyloldihydroxyethyleneurea (Me-DMDHEU) and dimethylolethyleneurea (DMEU), were obtained from textile chemical suppliers; methyl dimethylolcarbamate (DMMC) was prepared from formaldehyde and methyl carbamate (Reid et al., 1965). Formaldehyde was commercial formalin solution (37%). Other chemicals were reagent grade or the highest purity available. Catalysts were zinc nitrate, magnesium chloride, and magnesium chloride-citric acid mixture. Samples of several commercially finished cotton-containing fabrics were obtained from colleagues in the industry. Compositions of these finishes were not determined, but the fabrics are representative of those currently in production. Fabric samples prepared in the laboratory were treated by the conventional pad-dry-cure process. The level of finish applied was higher than those used in commercial production but was employed to yield a high level of durable press performance and to accentuate the formaldehyde release properties of the finished fabrics. A laboratory two-roll padder, pin frames, and ovens with mechanically circulating air were used. Samples of fabric were padded to about 90% wet pickup of the treatment solution which contained 9% finishing agent and, as catalyst, 0.6% zinc nitrate hexahydrate, 2.7% magnesium chloride hexahydrate, or 2.8% magnesium chloride hexahydrate-citric acid mixture (201, based on gram formula weights), mounted at original dimensions on pin frames, dried for 7 min a t 65 "C, and cured for 3 min at 160 "C. Portions of the samples were withdrawn in the unwashed state, and the remainer was used in the washing experiments. Three methods of washing were used: portable apartment-type, agitator, nonautomatic machine washing; automatic home-type machine washing; and simulated laboratory beaker washing. Three types of water were used: deionized water, pH 5.3-6; tap water from the New Orleans municipal supply, pH about 9.5; and tap water from a suburban New Orleans water district, pH about 7.5. The wash cycle consisted of a 15-min wash at 60 "C, followed by three 3-min rinses at room temperature. After washing, fabrics were tumble-dried in a gas-fired, home dryer. Total formaldehyde analyses were by the chromotropic acid method after digestion/distillation in sodium sulfate-sulfuric acid solution (Roff, 1956). Formaldehyde release values, expressed as micrograms of formaldehyde per gram of fabric (pg/g), were determined by the AATCC sealed jar method (AATCC Test Method 112-1984)with color development with Nash reagent (American Association of Textile Chemists and Colorists, 1985). Formaldehyde extracted from fabrics after 30 min in ice-water also was determined with Nash reagent. Results and Discussion The differences in formaldehyde release from cotton fabric treated with several finishing agents are shown in Figure 1. Formaldehyde release values from fabric in the
896 Ind. Eng. Chem. Res., Vol. 26, No. 5, 1987 999
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Figure 1. Cotton finished with various crosslinking agents, unwashed (0) and after washing in deionized water (W).
3
5 7 9 pH OF W A S H W A T E R
11
Figure 3. Formaldehyde release of DMDHEU-finished cotton vs. pH of wash water at various locations (Reinhardt et al., 1981). Table I. Formaldehyde Release of S i x Commercially Finished Cotton Fabrics Washed at Three pH Levels commerformaldehyde release, pg/g cially not washed washed washed finished washed at pH 5.3 at pH 7.6 at pH 9.2 fabric A 444 133 673 1452 B 402 92 165 272 355 262 640 1301 C D 185 105 636 898 E 122 99 554 694 F 80 45 357 719
w v)
U 450
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-
inhardt and Andrews, 1983,1984; Reinhardt et al., 1981).
0 0
5
15 20 WASH CYCLES
10
25
Figure 2. Repeated washing of DMDHEU-finished cotton.
unwashed state and after washing in deionized water are plotted as bar graphs. The unwashed values were normalized to 1.0, and the washed values are plotted as fractions of this value. The actual formaldehyde release values, as pg/g, are listed above each bar. It can be noted that the effect of washing on the formaldehyde release values varied among the finishes and that the change due to washing was great, both on an actual and on a fractional basis. Figure 2 shows the effect of repeated wash cycles by AATCC Test Method 124-1978 (American Association of Textile Chemists and Colorists, 1985) on the formaldehyde release from cotton printcloth finished with DMDHEU. Formaldehyde release was substantially reduced by the first wash cycle. Additional washing through about the fifth cycle produced a small further reduction. After the fifth cycle, formaldehyde release reached a level below which there was only little change. The relatively large decrease in the first wash cycle can be attributed to extraction of free formaldehyde and unbound products from the unwashed material. Possibly, some easily removable substances and linkages that survived the first wash were then removed in the next wash cycles. The formaldehyde release value of about 200 pg/g which was exhibited from the 10th through the 25th wash cycles probably reflects the release due to finish hydrolysis that results from the conditions of the standard AATCC test procedure. We have discussed the influence of the pH of the wash water on the level of formaldehyde release realized from washing various finished fabrics in previous papers (Re-
This influence varies with the chemical nature of the finish. Fabric finished with DMDHEU is particularly sensitive to washing at an alkaline pH. Figure 3 shows the range of formaldehyde release values that were obtained when a DMDHEU-finished cotton was washed at various locations, and the results were related to the pH of the wash water at each particular site. Regression analysis of the data indicated that the relationship between formaldehyde release values and pH of the wash water fitted a straight line with a least-squares correlation coefficient of 0.909, The formaldehyde release values obtained varied from about 600to 1200 pg/g depending upon the pH of the wash water. Further evidence of the relationship between formaldehyde release and pH of washing is shown in Table I. Six commercially finished durable press fabrics were washed in an apartment-size washer with water at three pH levels: pH 5.3, deionized water; pH 7.6, suburban New Orleans tap water; and pH 9.2, New Orleans city tap water. The formaldehyde release values after washing and those of the unwashed fabrics are listed. Formaldehyde release of the unwashed fabrics ranged from 80 to 444 pg/g. Washing at pH 5.3 lowered the formaldehyde release of all samples. However, only fabric B exhibited values lower than the unwashed after washing at pH 7.6 and 9.2. All of the other fabrics had higher formaldehyde release values after washing at these pH levels than did the unwashed fabrics. Furthermore, the release values were higher from the pH 9.2 wash than from the pH 7.6 wash. These data indicate that the response of all finishes to washing is not the same, although all of these commercial fabrics had higher formaldehyde release values as a function of higher pH in washing. The reason for this
Ind. Eng. Chem. Res., Vol. 26, No. 5, 1987 897 Table 11. Total Formaldehyde, Formaldehyde Release, and Extractable Formaldehyde of Cottons Washed in Slightly Acidic Deionized Water and Moderately Alkaline Tap Water HCHO HCHO total release, extracted, HCHO, AATCC ice-water, fabric % teat, w g / g 30 min, w g / g commercially finished fabric no wash 0.91 435 45 deionized water wash 0.82 190 20 0.79 1091 tap water wash 35 DMDHEU-finished fabric 2.45 871 60 no wash 2.53 673 25 deionized water wash 2.47 1868 55 tap water wash Me-DMDHEU-finished fabric no wash 2.05 192 35 deionized water wash 1.96 99 15 tap water wash 2.00 358 20
relationship is still unexplained although we believe that the likely cause is hydrolysis of some portion or moiety of the finish. The data of Table I1 shed some light on the changes that are brought about by washing in mildly acidic deionized water and in alkaline tap water. The results were obtained with a commercially finished fabric and with cotton finished in the laboratory with DMDHEU and MeDMDHEU. Any change in total formaldehyde contents from washing was relatively small, and there was no clear correlation between the change and the type (and pH) of the wash. The formaldehyde release values confirm the behavior that has been shown above. That is, formaldehyde release, relative to the unwashed, was lowered by washing in deionized water and increased by washing in the alkaline tap water. The formaldehyde extracted by ice-water, we feel, is a measure of the free formaldehyde in the fabric (Andrews and Reinhardt, 1986). The ice-water extraction probably removes free formaldehyde without causing much, if any, finish hydrolysis. The data in the last column of Table I1 indicate that free formaldehyde was highest in the unwashed fabrics and was decreased by washing both in deionized and in tap water. The formaldehyde extracted from the tap water washed fabrics was higher than from the deionized water washed fabrics. This difference may denote that there was less free formaldehyde after washing the fabrics in deionized than in tap water. Alternatively, it may be that there are moieties in these tap water washed fabrics that, even in ice-water, are more readily subject to hydrolysis than are the deionized-water washed fabrics. Water hardness is an important water property. It plays a role in determining the pH of various tap waters and was considered as a factor in washing. Washings were carried out in waters of various hardness levels. Deionized water was further purified to zero level hardness. Portions of this water were then artificially adjusted to hardness levels that are described as soft (calcium carbonate equivalent to 30 mg/L), moderately hard (90 mg/L), and hard (150 mg/L) (Skougstad, 1970). The pH of these waters was 8.6-8.8. Samples of cotton finished with DMDHEU and with DMEU were washed at the various hardness levels, and the formaldehyde release values are listed (Table 111). With DMDHEU-finished cotton, the results were like those we have seen above-washing in deionized water lowered formaldehyde release while washing in the slightly alkaline hardened waters increased formaldehyde release. Results with DMEU-finished cotton, however, were different. This finish is more stable than that of DMDHEU
Table 111. Influence of Hardness of Wash Water on Formaldehyde Release HCHO release, pg/g hardness of wash water DMDHEUDMEU(mg/L of calcium finished finished carbonate) cotton cotton not washed 951 5263 deionized water (0) 781 1152 soft water (30) 1393 1104 moderately hard water (90) 1615 1146 hard water (150) 1515 1151 Table IV. Influence on Formaldehyde Release of Type of Detergent and Adjustment of pH of Wash Water HCHO release, DMDHEU/zinc nitrate finished fabric fidg not washed 904 washed in deionized water, nonionic detergent (pH 6.5) 383 in tap water, AATCC std. detergent (pH 10.1) 1475 1145 in tap water, nonionic detergent (pH 9.7) in tap water adj. to pH 7, nonionic detergent (pH 706 6.9)
to moderately alkaline washing, and there was no obvious effect on formaldehyde release as a function of water hardness. All of the washings lowered formaldehyde release and all to essentially the same level. Table IV presents formaldehyde release results obtained as a function of the type of detergent used and of adjustment of the pH of tap water in washing. These washings were carried out in an automatic home-type washing machine on cotton printcloth finished with DMDHEU. Formaldehyde release was lowered, compared to unwashed fabric, by washing with nonionic detergent in deionized water (pH 6.5) and in tap water adjusted to pH 7. Washing in tap water, without pH adjustment, with either nonionic detergent or AATCC standard detergent (American Association of Textile Chemists and Colorists, 1985) gave formaldehyde release values higher than that of the unwashed fabric. The standard detergent (built) resulted in wash water with a higher pH than did the nonionic detergent: difference, 0.4 pH unit. Formaldehyde release from washing with the former was about 30% higher than from washing with the latter. Although the oxidative action of sodium hypochlorite might be expected to have a beneficial effect in washing to decrease formaldehyde release, this proved not to be the case. The use of a home-type commercial hypochlorite product in washing two DMDHEU-finished cottons increased formaldehyde release relative to the unwashed fabrics. Formaldehyde release values of the unwashed fabrics were 608 and 875 Fglg, respectively, and after washing in the presence of hypochlorite (pH lo), they were 1605 and 1792 Fg/g. Buffered rinsing in the washing process was investigated with DMDHEU-finished cotton. The wash procedure was conducted on a laboratory scale in beakers. It consisted of a l5-min washing in either tap or deionized water followed by three 3-min rinses in buffered solutions of the indicated pH levels. The washed fabrics were then dried and formaldehyde release values determined (Figure 4). Compared with the unwashed fabric, washing in tap water increased and washing in deionized water decreased formaldehyde release. Formaldehyde release of samples washed in tap water was improved by buffered rinsing with the values generally lower as a function of lower pH. Although buffered rinsing lowered release values from that of the tap water wash, the
898 Ind. Eng. Chem. Res., Vol. 26, No. 5, 1987
including deionization, pH, and hardness, and by detergent, hypochlorite bleach, and buffered rinses. Although, at fiist glance, the washing of a finished cotton would seem to be a simple means for lowering formaldehyde release, its effects can be very complex. Furthermore, the optimum washing varies with the chemical nature of the finish and its decomposition reactions. Registry No. DMDHEU, 1854-26-8; DMEU, 136-84-5; H20,
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Literature Cited
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Figure 4. Buffered rinsing in the washing of DMDHEU-finished cotton.
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Achwal, W. B.; Kamat, S. Y. J . T e x t . Assoc. 1979,40, 3-10. American Association of Textile Chemists and Colorists AATCC Technical Manual; AATCC: Research Triangle Park, NC, 1985; Vol. 60. Andrews, B. A. K.; Harper, R. J., Jr. Text. Res. J. 1980,50,177-184. Andrews, B. A. K.; Harper, R. J., Jr. Text. Chem. Color. 1984,16(10), 27-31, 38. Andrews, B. A. K.; Harper, R. J., Jr.; Smith, R. D.; Reed, J. W. Text. Chem. Color. 1980a, 12, 287-291. Andrews, B. A. K.; Harper, R. J., Jr.; Vail, S.L. Text. Res. J. 1980b, 50, 315-322. Andrews, B. A. K.; Reinhardt, R. M., Text. Res. J . 1982,52,123-132. Andrews, B. A. K.; Reinhardt, R. M. Text. Chem. Color. 1984, 16, 100-105. ~ . ~ . .
WUh 0
-
NOT WASHED
WASHED
3
4
6
8
1
8
D
I
10
DH OF RINSE
Figure 5. Buffered rinsing in the washing of DMEU-finished cotton.
improvement was only to about that of the unwashed fabric. Formaldehyde release of samples washed in deionized water was further lowered by buffered rinsing in the pH range of about 7-8.5. Rinses below pH 7 and at pH 9 gave release values about equal to that of the deionized water wash alone. Figure 5 shows formaldehyde release values from a similar experiment with DMEU-finished fabric. The results are consistent with known hydrolytic stability properties of this finish. That is, washing in either slightly alkaline tap water or in deionized water decreased formaldehyde release with the former a little more effectively than the latter. Buffered rinsing, except at the lowest pH level, had only nominal effect on DMEU-treated fabric washed in tap water. Formaldehyde release of samples washed in deionized water was adversely affected by buffered rinsing below pH 7 . Summary This study has extended our earlier research on the influence of washing on formaldehyde release from finished fabrics. It affords a deeper understanding of the washing/ formaldehyde release relationship. To be effective in lowering the formaldehyde release of a finished fabric, a washing must remove free formaldehyde from the fabric and leave the finish in a state that is stable to hydrolytic or other degradation that can release additional free formaldehyde through some decomposition mechanism. We have reviewed the factors that contribute to the formaldehyde release character of finishes and have shown that variations in washing can influence the formaldehyde release performance of a finished cotton. In particular, new data have been presented that illustrate some of the effects that can be produced in washing by water quality,
.
Andrews, B. A. K.; Reinhardt, R. M. Book Pap., Znt. Conf. Exh.AATCC 1985, 174-179. Andrews, B. A. K.; Reinhardt, R. M. Text. Res. J. 1986,56,115-120. Beck, K. R.; Pasad, D. M. T e x t . Res. J . 1982,52, 269-274. Bille, H. E., Int. Dyer 1984, 169(3), 23. Cashen, N. A. Text. Res. J. 1979,49, 480-484. Cooke, T. F. Text. Chem. Color. 1983, 15, 233-238. Cooke, T. F.; Weigmann, H.-D., T e x t . Chem. Color. 1982, 14, 101-106, 136-144. Day, M. 0.; Reeves, W. A. Book Pap., Natl. Tech. Conf.-AATCC 1983,335-340. Gregorian, R. S.; Namboodri, C. G. US Patent 4472 165, 1984. Harper, R. J., Jr. Book Pap., NatZ. Tech. Conf.-AATCC 1983, 120-125. Hebeish, A.; Nassar, F. A.; Ibrahim, N. A.; Islam, A. M. Angew. Makromol. Chem. 1979a, 81, 95-107. Hebeish, A.; Nassar, F. A.; Ibrahim, N. A.; Islam, A. M. Angew. Makromol. Chem. 1979b, 82, 27-37. Hendrix, J. E.; Payet, G. L. US Patent 4 447 241, 1984. Jaco, P. J.; Hendrix, J. E. T e x t . Chem. Color. 1982, 14, 194-199. Kaneko, H.; Yokoyama, S. Sen'i Seihu Shohi Kagku 1976, 17, 380-384. Kim, E. A.; Yeh, K.; Smith, B. F. Book Pap., I n t . Conf. Exh.AATCC 1984, 314-320. Kullman, R. M. H.; Pepperman, A. B.; Vail, S. L. Text. Chem. Color. 1978, 10, 195-199. Nieuwenhuis, K. J. Text. Res. J. 1982, 52, 416. North, B. F. T e x t . Chem. Color. 1977, 9, 223-225. Pai, P. S.US Patent 4331438, 1982. Palmetto Section AATCC Text. Chem. Color. 1982a, 14, 28-39. Palmetto Section AATCC Text. Chem. Color. 198213, 14, 249-256. Perry, R. S.; Tsou, C.-H.; Lee, C. S. Text. Chem. Color. 1980, 12, 311-316. Petersen, H.; Pai, P. S. Text. Res. J . 1981, 51, 282-302. Petersen, H.; Petri, N. Melliand Textilber. 1985, 66, 217-222, 285-295, 363-369. Reeves, W. A.; Day, M. 0. J . Coated Fabr. 1983, 13, 50-58. Reeves, W. A.; Day, M. 0.;McLellan, K. R.; Vigo, T. L. Text. Res. J . 1981, 51, 481-485. Reeves, W. A.; Salleh, N. M. Text. Res. J . 1984,54, 463-470. Reeves, W. A.; Salleh, N. M.; Abu, R. B. Am. Dyest. Rep. 1983, 72(5), 22-26, 36. Reid, J. D.; Arceneaux, R. L.; Reinhardt, R. M.; Harris, J. A. Am. Dyest. Rep. 1960, 49, 490-495. Reid, 3. D.; Reinhardt, R. M.; Bruno, J. S.A m . Dyest. Rep. 1965,54, 485-491. Reid, J. D.; Reinhardt, R. M.; Fenner, T. W.; Harris, J. A. Am. Dyest. Rep. 1962, 51, 150-153, 157. Reinhardt, R. M. Text. Res. J . 1983, 53, 493-496. Reinhardt, R. M.; Andrews, B. A. K. Book Pap., Natl. Tech. Conf.-AATCC 1983, 89-96. Reinhardt, R. M.; Andrews, B. A. K. Text. Chem. Color. 1984, 16, 235-240.
Ind. Eng. Chem. Res. 1987,26,899-902 Reinhardt, R. M.; Andrews, B. A. K.; Harper, R. J., Jr. Text. Res. J. 1981,51, 263-270. Reinhardt, R. M.; Daigle, D. J. Text. Res. J. 1984, 54, 98-104. Reinhardt, R. M.; Harper, R. J., Jr. J. Coated Fabr. 1984, 13, 216-227. Reinhardt, R. M.; Kullman, R. M. H.; Reid, J. D.; Reeves, W. A. Text. Chem. Color. 1972,4,89-90. Roff, W. J. J. Text. Znst. 1956, 47, T309-T318. Seguchi, K.; Hagino, T.; Kashino, T. Sen? Seihin Shohi Kagaku 1978, 19, 270-274. Skougstad, M. W. Kirk-Othmer Encycl. Chem. Technol., 2nd Ed. 1970,21,688-707. Tomasino, C.; Taylor, M. B., 11. Text. Chem. Color. 1984, 16, 259-264.
899
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Receiued for review July 18, 1986 Accepted January 21, 1987
Poly (vinyl phthalate-azidophthalate): 4 - (Dimet hylamino)pyridine- Catalyzed Esterification of Poly(vinyl alcohol) and Photo- Cross-Linking Guy Levesque* and Gerard Chiron Laboratoire de Chimie des Composls Thioorganiques (Associ6 au C.N.R.S.), Uniuersit6 de Caen, 14032 Caen, France
Poly(viny1 alcohol) (PVOH) phthalylation is rapid in dimethyl sulfoxide solution a t room temperature in the presence of triethylamine and 4-(dimethylamino)pyridine. When alkylation of the poly(viny1 ammonium phthalate) was achieved without polymer isolation, this process gave methylated poly(viny1phthalates) of adjustable acidity, suitable for photoresist purposes. Reactions with mixtures of phthalic and 3-azidophthalic anhydrides, followed by partial methylation, offered photo-crosslinkable polyesters whose relative photolysis rates of azide groups increase as the azide concentration decreases. In the course of investigations for a negative photoresist that could be used in stable precoated plates which may be stored for months, developed with common nontoxic solvents and etched both in acid or basic media, we have defined the main component of such a formulation as a polymer able to cross-link through self-reaction upon illumination by near-UV light. As several photoresist-mainly positive ones-consist of modified phenol-formaldehyde resins, we looked for polymers containing similar structural units: phenyl rings, hydroxyl groups, low acidity, etc. It would be also advisable that such polymers might be obtained in a one-pot reaction path, and we have studied the esterification of poly(viny1 alcohol) with phthalic anhydrides-including 3-azidophthalicanhydride-as a photo-cross-linking group, followed by alkylation of the intermediate half ester salt (Scheme I). This process allows the adjustment ad libitum of numerous parameters such as acetate content, overall degree of phthalylation, acidity, and azide group concentration, all of them being important to control in photoresist applications. The polymer must be either photodegradable or photo-cross-linkable, soluble in a nontoxic solvent, thus giving a solution of sufficient viscosity for plate enduction; after illumination, the solubility differences between irradiated and masked areas must be high enough to allow rapid developing. Moreover, the remaining polymer must both protect the unrevealed area from etching and be soluble (or swellable) enough to allow the final stripping of the substrate. In fact, the previously described poly(viny1 azidophthalate) (Merrill and Unruh, 1963) represents an expensive solution as, in the cross-linking step, each azide
OH
OH
04s
co
I,
LO:
?
?
'HNEI,
OH
group upon photolysis generates a nitrene which needs to react with another structure, preferably a benzene ring. We supposed that equivalent amounts of phthalic ester groups could attractively replace half (or more) of the azidophthalates without pulling down the cross-linking ability. As we hoped to prepare a photoresist supporting both alkaline and acid etching, it was necessary to alkylate significant amounts of acid groups formed in the phthalylation of poly(viny1 alcohol). The previously described phthalylation was realized in pyridine: we have tested other reaction media and the well-known esterification catalyst, 4-(dimethylamino)pyridine (DMAp) (Steglich and Holfe, 1969; Guibe-Jampel
0888-5885/87/2626-0899$01.50~0 0 1987 American Chemical Society
