Vulcanization and Vulcanizing Agents [antikvár]

Foreword Since the discovery of vulcanization by Charles Goodyear and of organic accelerators by G. Oenslager and F. Hofmann and co-workers, no comprehensive survey of the large field of crosslinking, and of the systems necessary for that purpose, has been made. To celebrate the fiftieth anniversary of its production of organic accelerators, Farbenfabriken Bayer AG, of Leverkusen, Germany, generously provided an opportunity for the extensive literature on the subject of vulcanization to be collated and critically examined. In view of the widespread interest which was aroused by the original monograph published by Farbenfabriken Bayer AG, an English translation of the revised and substantially enlarged monograph was placed at the disposal of Maclaren Sons. The table in the German edition listing the chemicals manufactured by Farbenfabriken Bayer AG for vulcanization purposes has not, however, been included in the English version. The development of organic accelerators goes back to the year 1906. In the U.S.A. attempts were made to improve the more or less capricious" vulcanization of wild rubber by using aniline. In Germany attempts were made to vulcanize synthetic rubber withjjigeridine and other bases, as well as with their reaction products with carbon disulphide, the dithio-carbamates. The appropriate application of the first organic accelerators to natural rubber for the purpose of reducing vulcanization times and improving the mechanical properties of the vulcanizates then proved unprecedently successful. One class of substances after another was found; and each discovery led to further technical and economic advantages until, finally, this remarkable development reached its climax in the products of the sulphenamide class. But with the discovery of the various classes of accelerator—including the sulphenamides, with which almost all desired vulcanization effects can be obtained—research did not come to a halt. Instead it tended, more and more, to study problems in depth. The requirements which have to be fulfilled by rubber are becoming more stringent from day to day; new types of rubber are constantly appearing on the market and improved vulcanization processes, which bring fresh problems with them, are invented from time to time. For this reason the development of accelerators has still not yet been concluded. Again and again new combinations or substances belonging to the familiar classes, but having superior properties, are brought on to the market. In view of the wealth of technical problems that has to be mastered, the appropriate use of the many hundreds of accelerators now commercially available is a task for the virtuoso. Such a person would of course have ix