1954 TWENTY-FRST CONFERENCE 135 SUGAR CANE WAX A SURVEY OF CRUDE WAXES AND THER BLEACHNG WTH CHROMC ACD Studies in Waxes. Part V By G. B, CARTER, P. M. HJNTEK and J. A. LAMBERTON Sugar cane waxes, obtained by extracting mud from twenty-eight mills, have been examined. Each of the waxes, after freeing of inorganic material, has been bleached by oxidation with chromic acid. Certain properties of the crude, de-ashed, and bleached waxes are recorded. t has been shown [] that sugar cane wax which has been freed of mineral matter, whether it has or has not been hardened by distilling from it the softer components, maj7 be bleached by chromic acid to give a light coloured acidic wax. t seemed desirable to test the general application of this method by using it upon a wide range of' waxes, for the earlier investigations had been concerned almost entirely with wax from the Moreton mill, Nambour [ 1, 2 ]. So that the waxes selected would be ikelv to show the variation to be found in Australia, grab samples of filter muds from twenty-eight mills were obtained and' the waxes extracted. Previouslv it was re~orted r21 that the crude wax from the Moreton mill, wheg freed of hnerall;atter and bleached by chromic acid, gave an acidic product, of which the ester and amide derivatives showed properties only slightly inferior to those of like derivatives from a wax which had been hardened by vacuum refining before bleaching. Tt therefore seemed possible that the removal of soft wax components by vacuum distillation might not be necessary. But a satisfactory bleaching ~rocess should be applicable to any crude sugar cane wax and, moreover, it should give a reasonably uniform product. Crude cane wax is known to vary considerably in its physical properties [3] and, if bleaching alone did not eliminate this variability, it would be necessary first to use vacuum distillation to bring all the waxes to a similar degree of hardness. The Crude Waxes The filter mud was dried to a water content of about 10 per (see Table ), and the crude wax extracted with hot petroleum solvent. The yields of wax, both on a laboratory and a larger (50 lb. lots) * Previous paper in this series:-hatt and Lamberton, "Sugar Cane Wax. The Effect of Chemical Modification upon the Physical Properties." Proceedings Q.S.S.C.T. Twentieth Conference, p. 29.
TABLE -Properties of crude waxes. Filter mud Crude wax Mill Major varieties of cane Sample received Water1 per Bulk density b. per cu. ft. field-per cent Labors. tory.- - Pilot plant Meltpoint "C. Ash Acid odine Colour Lovibond rating N.T. Description 1. Babinda.. 2. Bingera.. 3. Broadwater 4. Condong 5. Fairymead.. 6. Goondi.. 7. Hambledon.. 8. Harwood.. 9. lnvicta.... 10. lsis.... il. Kalamia. 12. Macknade. 13. Marian 14. Maryborough.. 15. Millaquin.. 16. Moreton.. 17. Mossman.. 8. Mourilyan 9. Mulgrave.!O. North Eton!. Pioneer..!2. Plane Creek.!3. Pleystowe!4. Proserpine..!5. Racecourse.. 16. South lohnstone :7. Tully...8. Victoria.., Badil; C.P. 29/116 Vesta Pollux Pindar Vesta C.P. 29,116 Pindar, Eros Q.28, Q.50 C.P. 29/116 4.47 rroian, Badila ; Badila 2.28, 4.50 2.28, 4.50 rrojan, Badila rroian, Badila 'indar Aug., 1952 June, 1952 July, 1952 June, 1952 Oa., 1951 July, 1952-1 After drying. 5.1 8.1 13.5 8.3 7.7 17.8 16.7 15.7 13.7 6.6 13.4 14.3 10.8 11.0 7.8 10.0 7.6 4.9 11.7 18.0 5.6 11.0 8.5 13.7 11.1 7.4 8.8 11.9 * V. = Very Dark Green, - B = Brown. * -B. V. V. V. B. V. V. V. V. V. -
1954 TWENTY-FRST CONFERENCE 137 scale are reported in Table and refer to the dry-weight of mud. The larger scale extraction was less thorough and was obtained with a shorter extraction time; accordingly the yields are somewhat lower, but probably indicate more nearly those to be expected on a commercial scale. The results set out in Table show a wide variation in the ash content of the extracted wax (0.7 to 7.0 per ) and also in the iodine and acid. The waxes were too dark, generally brown or green, for direct, measurement of the colour on the Lovibond Scale. The colours given in Table were calculated from measurements made with the wax after dilution with nine parts by weight of paraffin wax. The major cane varieties being crushed at the mill when the grab samples were, taken, are listed in Table. They are recorded only for the sake of completeness. De-Ashed and Bleached Waxes Table 1 shows the properties of the de-ashed and the bleached waxes. De-ashing, which was accomplished by treatment with dilute hydrochloric acid, always made the wax softer. All the waxes were satisfactorily bleached by oxidation with chromic acid. n these experiments every wax was subjected to the same degree of oxidation (i.e. the bleaching was continued until a definite amount of chromic acid had been used). This was done, even though some of the waxes would have given a light coloured wax in a far shorter reaction time and with much less chromic acid. The oxidation with chromic acid was carried out in two stages. Usually the first stage of the oxidation was complete in five hours but some waxes required a longer time and in one instance (Mossman) the time was 13-14 hours. The differences are even more pronounced in the second stage of bleaching and the time for complete exhaustion of the chromic acid varies from five to fifty-five hours. The bleached waxes were generally very pale in cdour, as the Lovibond ratings, which are for undiluted wax, show. Many were slightly sticky to touch and having a Brine11 hardness of less than 0.8 were too soft to be tested on the 'ickers hardness tester. These s can be compared with the hardness of 1.6 obtained with the corresponding product from Moreton mill wax and reported in the previous paper of this series. On the other hand a few of the waxes are much harder although mostly still too soft for use as hard wax components in polishes. The wax from one mill ( ossman) showed exceptional properties. Although the crude wax was of low ash content,it possessed an exceptionally high melting point. t could have been bleached with much less bleaching agent and a high melting point was shown also in the bleached material. Whether the properties c;l one grab sample are typical of the wax available at Mossman throughout the year cannot be stated. t is evident that the properties of the crude waxes vary widely and under suitable conditions waxes can be obtained with much more attractive properties than those normally encountered.
TABLE l-properties of de-ashed and bleached waxes. De-ashed wax Bleached wax (bleach number 1.5) Mill Yield -i-~leachin~ time Ash hr. --- i Stage 2 Yield Melting point "C. Acid Colour Lovi bond rating Descript ion * Hardness (Brinell) 1. Babinda.. 2. Bingera.. 3. Broadwater.. 4. Condong.. 5. Fairymead.. 6. Goondi.. 7. Hambledon.. 8. Harwood 9. nvicta. 10. lsis... 11. Kalamia. 12. Macknade.. 13. Marian 14. Maryborough 15. Millaquin.. 16. Moreton 17. Mossman 18. Mourilyan 19. Mulgrave 20. North Eton.. 21. Pioneer 22. Plane Creek.. 23. Pleystowe.. 24. Proserpine 15. Racecourse..!6. South Johnstone 7 Tuly..!8. Victoria.. * Y = Yellow; W = i = Brown; G = --- jreen; P = Pale. 0.3 (B) 0.1 0.1 1.o 0.9 0.6 (B) 1.o 2.4 2.0 0.4 (B) 0.7 0.2 (B) 1.5 0.9 0.5 0.3.2 0.3 (B); 0.1 0.2 (B) ; 0.8 (B) 0.4 (B) ; 0.5 0.4 ; 0.5 1.5 ;1.0 0.3 ; 0.4 0.4 ; 0.7 0.5 : 1.5 0.2 (B) ; 0.1 (B) 1.1 :1.2 02 (B); 0.4 (B) 1.5 ;1.2 P. Y-G W. P.B. PA.; Y. Y. Y-G. Y-G; P.B. P.Y, Y-G. ; P.B. P. Y-G. P. Y-G. Y. Y.; P.B. P.B.; Y.
1954 TWENTY-FRST CONFERENCE 139 Experimental The filter muds were dried to approximately 10 per water content as soon as they were received and the waxes extracted with hot Shell X2 solvent. After dewashing, the waxes were bleached by the method of Hatt, Strasser and Troyahn []. The amount of chromic acid used in the bleachings corresponds to a bleach number of 1.5. Bleachings were done in duplicate using 30 g. of de-ashed wax and the chromic acid solution (110 g. CrOs and 420 g. HZSO* per litre) was added in two stages. n the first stage, 27 g. of chromic acid were added and a further 18g. in the second stage. Heating and stirring were conti.nued until the chromic acid had been reduced. The yields in duplicate runs showed good agreement. Mostcof the waxes remained liquid throughout the bleaching process, but one (Mossman) formed lumps during the first stage and this made stirring difficult. The softness of most the bleached waxes and their great variability, emphasizes that, if it is aesired to produce hard waxes consistently, it will be necessary to vacuum refine the de-ashed wax. Nevertheless, there seem to be conditions under which crude waxes of greater hardness and higher melting point can be obtained. t is clearly desirable1 to discover what these conditions are. There is variation in this respect in the crude waxes from a single mill. Recent samples of crude wa@ from Moreton have given a soft wax (H = 0.9) when bleached without vacuum refining; earlier samples were much harder (H = 1.6). Acknowledgment The authors thank the managements of the mills mentioned in this paper for their co-operation in providing us with samples of filter mud and for information on the types of cane being crushed. REFERENCES [l] Hatt, H. H., Strasser, P. H. A., and Troyahn, W. J.: 1950. "The Refining and Bleaching of Sugar Cane Wax." Proceedings Q.S.S.C.T. Seventeenth Conference, p. 61. [2] Hatt, H. H., and Lamberton, J. A,: 1953. "Sugar Cane Wax. The Effect of Chemical Modification upon the Physical Properties." Proceedings Q.S.S.C.T. Twentieth Conference, p. 29. [3] Balch, R. T.: 1941. "Preliminary Report on Sugar Cane Wax." Sugar Journal, 4, No. 6, p. 24-9. C.A. 1942, p. 5375. Commonwealth Scientific and ndustrial Research Organization, Division of ndustrial Chemistry, Melbourne.