Study On The Synthesis, Characterization And Application Of Diethyldithiocarbamate Antimony Vulcanizing Accelerator

Usually the rubber crosslinking process is called vulcanization, the material of making rubber crosslinking is called vulcanization agent, also is the crosslinking agent. Curing is a final process which rubber products are made, it is also the most main physical-chemical process. The process makes unvulcanized rubber blend into cured rubber, rubber macromolecules from linear chain transforms into three dimensional space net structure, which makes rubber products gain excellent physical-chemical and mechanical properties. Rubber products performance often depends on the curing system design in rubber formulation and vulcanization process technology to a great extent.In the industrial application rubber vulcanization agents (crosslinking agents) are usually composed of various components, which are called the curing system. If using only crosslinking agents, rubber blend vulcanization are slow in most cases, do not have practical value, especially when using sulphur as crosslinking agent of rubber. So the in curing system still must add those rubber auxiliaries, which can speed up the rubber vulcanization speed, lower curing temperature, reduce the amount of sulfur, shorten curing time, improve crosslinking degree and the physical and mechanical properties of vulcanizates, they are vulcanization accelerator and curing activator. Vulcanization accelerators have many kinds, all kinds of system of accelerators have different vulcanization promoting mechanism. Dithiocarbamates are acidictype accelerator, their most variety have the very strong promoting vulcanization effect, which are said "speeding vulcanization accelerator". Generally it is used for low temperature vulcanization, especially suitable for little content of double bond(for example IIR,EPDM etc), vulcanizing speed slow and the curing and forming process of saturated rubber with sulfur, which has a wide range of uses in industrial production.In this paper, firstly, the vulcanizing and promoting mechanism of rubber and present situation of rubber accelerator development are discussed and introduced about domestically and abroad. Then, in order to undertake own project of the synthesis, characterization, application and research mechanism of speeding vulcanization accelerator, using the new method synthesized the diethyl-dithiocarbamate antimony (SDEC), and the the synthesis, characterization and application technology of SDEC were researched in-depth.The dithiocarbamate vulcanization accelerators are by means of the dithiocarbamic ligand and metal (Zn, Cu, Cd, Pb, Fe, Bi, Na, K, NH4+, etc.) or half metal (Se, Te) to form the complex. Their synthesis process route can be divided into two kinds, one kind is:the first to take the water as solvent synthesize diethyl(or dimethyl) dithiocarbamic ligands, the second synthesized ligands and Zn salt (ZnCl2), Cu salt (CUCl2), Fe salt (FeCl3), the oxidation of tellurium (TeO2) etc., respectively manufacture the dithiocarbamate vulcanization accelerator through the complex reaction, such as ZDEC, ZDMC, CDMC and TDEC etc. Because of the corresponding metal salt hydrolyze more easily, and further reduce the waste water of synthetic reaction to adapt to the need of environmental protection, the new method is:use a metal oxide or half metal oxide and other raw materials in the organic solvent "one-step" process synthesize dithiocarbamate vulcanization accelerator, in addition its organic solvent can recovery recycling.In this paper writer selected antimony oxide (Sb2O3) as raw material and synthesized diethyl dithiocarbamate antimony (SDEC) as speeding vulcanization accelerator by the "one-step" synthesis technology. The paper mainly research content as follows:1. Through the synthesis process improvement and raising production rate of SDEC show that the optimization of the "one-step" synthesis process route and more accord with environmental protection requirement, the SDEC yield reached 80%, the solvent recovery recycling, and this method is more suitable for industrial production;2. Applying FT-IR, NMR and Elemental Analyzer, Thermal Analyzer and Single Crystal X-ray Diffractometer test, analyse and characterize the molecule and single crystal structure of SDEC. The results show that SDEC is a three ligand, five coordination compounds, the crystal structure is belong to three inclined crystal department, crystal melting point Tm= 135℃, TGA shows that it is begin to thermal decomposition in 212℃to 363℃range, the total weight loss is ratio about 68%(N2 atmosphere), the thermal stability is good;3. In this paper synthetic SDEC is added in the vulcanization system of EPDM rubber blend, the vulcanization activation energy Ea and Mooney viscosity of rubber blend are determined by the vulcameter and Mooney Viscometer, the mechanical properties, heat aging performance and thermal stability of vulcanized rubber are tested also. The results of the study show that, compared with the application of TDEC as vulcanization accelerator of EPDM mixing rubber and blank samples, SDEC vulcanization promote efficiency is very close to TDEC, the SDEC is a fine performance speeding vulcanization accelerator.