Tetramethyl thiuram disulphide

Tetramethyl succinonitrile Tetramethyl thiourea Tetramethyl thiuram disulphide (thiram) Tetranitromethane... 

Reduction of the adhesion level will occur if certain compounding ingredients are not avoided. The acceleration system has a direct effect on the adhesion level dibenzothiazole disulphide (MBTS) gives the highest adhesion levels. If a second accelerator is used, e g., tetramethyl thiuram disulphide (TMTD) or diphenyl guanidine (DPG), then the adhesion is significantly affected. Other ingredients which cause problems are plasticisers and process oils. 

Butyl 200, 25 furnace black, 5 zinc oxide, 1 stearic acid, 1 tetramethyl thiuram-disulphide, 0.5 mercaptobenzo-thiazole, 1 sulfur 40 min at 153° C Methyl methacrylate 55 39 31... 

Whereas Redfern [57] has pointed out the advantages of simultaneous thermal analysis techniques (particularly TG-DSC and TG-DTA) over techniques conducted singly, an even more complete thermal profile is provided when a thermal analyser is coupled to some form of gas analyser (MS or FTIR). Mohler and co-workers [51] have reported TG-DSC-MS of the thermal decomposition of the vulcanisation accelerator tetramethyl thiuram disulphide (TMTD) in rubber degradation of TMTD starts at about 155 °C, as evidenced by m/z 76 (CS2) and 44 (radical of the secondary dimethylamine). 

Trimethylol propane triacrylate Trimethylol propane trimethacrylate Tetramethyl thiuram disulphide Total correlation spectroscopy Time-of-flight MS Thermoplastic elastomer(s)... 

In sulphur cured rubbers, accelerators are generally used to reduce the dependency on sulphur in order to achieve more efficient vulcanisation, to improve heat and flex resistance due to the presence of more monosulphidic crosslinks, and to increase the cure rate of the rubber and improve production capacity. Two accelerators which have been shown to enhance bondability of rubbers are 2-mercaptobenzothiazole (MBT) and mercaptobenzothiazole disulphide (MBTS). An accelerator which is known to negatively impact on adhesion is tetramethyl thiuram disulphide (TMTD). 

Perthiomercaptides are also believed to be formed when certain sulphur-donors such as tetramethyl thiuram disulphide reacts with the zinc complex. It is thus possible to vulcanize a rubber by a mechanism broadly similar to that of an accelerated sulphur system without the use of elemental sulphur. 

Evidence for the formation of this intermediate has been most clearly demonstrated for systems based on the sulphur donor, tetramethyl thiuram disulphide (Figs 8.4 and 8.5). This evidence may be summarized as follows ... 

The use of sulphur donors in place of elemental sulphur has been practised since the early 1920s when it was found that the accelerators tetramethyl thiuram disulphide and tetraethyl thiuram disulphide in conjunction with zinc oxide gave vulcanizates with improved ageing properties when compared with conventional accelerated sulphur systems. For many years it was believed that vulcanization was brought about by the abstraction of one sulphur atom from the disulphide to yield the corresponding monosulphide... 

Several other sulphur donors have been investigated. In one study (Ascroft et ai, 1969) tetramethyl thiuram disulphide, tetraisopropyl thiuram disulphide, dimorpholyl disulphide, diisopropyl xanthogen disulphide and diisopropyl thiophosphoryl disulphide were compared alone and in blends. Mixtures of the dimorpholyl and the thiophosphoryl disulphides are characterized by long induction periods followed by high rates of vulcanization. The dimorpholyl disulphide, also known as N,N -dithiobismorpholine is available commercially as a vulcanizing agent. 

DOP dioctyl phthalate TMTD tetramethyl thiuram disulphide ... 

Until now the use of crosslinking systems based on thiuram disulphide for compounds which reach high temperatures has been difficult owing to the inadequacy of the scorch times. However, Leibbrandt has drawn attention to the development of systems comprising tetramethyl thiuram disulphide (or preferably dimethyl diphenyl thiuram disulphide), N-morpholinyl-2-benzothiazyl sulphenamide, a special retarder (Vulkalent E), and 0-5-0 8 phr of sulphur which, especially in the case of NBR, combine high processing safety with short vulcanisation times. The thiuram disulphide can be replaced by other sulphur donors (see Table 3 and Fig. 9). 

The effect is examined of tetramethyl thiuram disulphide (TMTD) on the heat ageing and oxidation of clay-filled NR, with reference to the plasticity retention index of NR, using thermal analysis and scanning electron microscopy test methods. The results showed that heat and oxygen resistant properties could be obtained when the clay-filled natural rubber compound was cured by semi-effective or effective curing systems, with 1.5 phr or 3.0 phr of TMTD. 3 refs. 

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