January 1949
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INDUSTRIAL AND ENGINEERING CHEMISTRY LITERATURE CITED
C R A C K I h G OF O T H E R H I G H P O L Y M E R S
A series of high polymeric materials was subjected t o pyrolysis in the extrusion cracking apparatus with a 5-cm. copper cracking zone. The results are collected in Table VIII. Polyisoprene was prepared by polymerizing isoprene in bulk with diazoaminobcnzcnc as catalyst (6). I t s iodine number was 283 in contrast to 355 for first latex crepe. The isoprene yield is comparatively high, an indication of a rather regular macromolecular pattern. Keoprene and polyvinyl chloride split off hydrogen chloride. ACKNOWLEDGMENT
The authors wish t o express their gratitude to A. van Rossem, director of the Research Department of the Rubber Foundation for permission to publish this paper.
(1) Bassett, H. L., and Williams, H. G., J . Chem. Soc., 1932, 2324. ( 2 ) Bolland, J. L., and Orr, W. J. C . , Trans. Inst. Rubber Ind., 21, 122 (1945). (3) Davis, E. L., Goldblatt, L. A , and Palkin, S., IND. ENG.CHBM., 38, 53 (1946). (4) Farmer, E. H., and Warren, F. L., J . Chem. Soc., 1931, 3221. (5) Gaade, W., unpublished data. (6) Koningsberger, C., and Salomon, G . , J . Polymer Sci., 1, 200 (1946). (7) Midgley, T., and Henne, H. L., J . Am. Chem. Soc., 51, 1216 (1929). (8) St,audinger, H., and Geiger, E., Helv. Chim. Acta, 9, 549 (1929). (9) Staudinger, H., and Klever, H. W., Ber., 44, 2212 (1911); 75, 2059 (1942). RECEIVED October 28, 1947.
Effect of Moisture Variations on Curing Rate of G IAN C. RUSH AND S. C. I
