Ebonite is generally made by vulcanising crude rubber to which has been added 3040% of sulphur with accelerators, zinc oxide, ebonite powder, etc. On obtaining ebonite directly from latex, there have been made only a few studies. The authors have made ebonite directly from latex and made studies on the influence of accelerators seen in this case. Natural latex with high percentage of sulphur added gives, when valcanised, ebonite as solid rubber similarly treated. Quick vulcanisation is also possible, if an ultra-accelerator is used. The authors describe their fundamental studies on (atex-ebonite). They added several types of marketsold organic accelerator and various percentage of sulphur to latex, and, on vulcanisation, have determined tensile strength, elongation, hardness and electric resistance of the vulcanisates. Further, comparative studies were made on the vulcanising characteristics of organic accelerators, on quantitatively analysing the combined sulphur. The result obtained show that Zn diethyl dithiocarbamate, Zn dibutyldithiocarbamate and tetramethylthiuram disulphide have all a similar effect, while Zn ethylphenyl dithiocarbamate has a slower effect than these.

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In the vulcanization of a rubber article, if the article is thick, the temperature in the interior may never reach the temperature of the heating medium, and unsteady state conduction occurs during the whole cure. Therefere, it is difficult to obtain thick rubber articles cured uniformly. In order to obtain the best performance from the thick vulcanized article, the rate of cure of interior compounds must be adjusted until they show satis factory balance during the curing period. In such a case, the theoretical method for obtaining temperature-time relations at selected points within a rubber article might be very useful. Authors have solved the basic equation for heat conduction in one dimension, assuming the shape of rubber article is a uniform thick slab having constant c, ρ, k, the whole slab is initially at a temperature θ', and one side of surface is exposed to a heating medium of temp θi, the other side of surface is exposed to a heating medium of temp θe, the rate of heat transfer from the heating medium to the surface is infinitely great, the heat of chemical reaction between rubber and sulfur is negligible.
The solution for the temperature θ selected points within a slab is :
θ (p, q) = θ_if_i (p, q) +θ_ef_e (p, q) +θf₀ (p, q)
f_i (p, q) = [1- {p+φ' (p, q)+φ' (p, q)}]
f_e (p, q) = {p+φ' (p, q)}
f₀(p, q)=φ' (p, q)
φ' (p, q) =2/π∞Σs= (-1) /S_s²π^2qsin (2S+1) πp
φ' (p, q) =4/π∞Σs=01/2S+1^e- (2S+1) ²πqsin (2S+1) πp p=x/a, q=αt/a², α=k/cρ
a : thickness, t : time, c : specific heat,
ρ : density, k : Thermal conductivity if θ_i=θ_e
θ (p, q) =θ_i {1-f₀ (p, q)} +θ'f₀ (p, q)
Then authors have explained the application of theoretical equation to vulcanization and the practical method for obtaining temperature time relations at selected points within a slab.

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In Report No. 1, authors have derived the theoretical equation for obtaining temperature-time relations at selected points within a slab from the basic equation for heat conduction in one dimension. The theoretical equation has been shown in the following from
θ (p, q) =Σθ^f
This paper has outlined the application of this equation to the heat conduction calculation in the vulcanization of tire. In the calculation of temperature rise in tire during vulcanization, theoretical f-values for a slab (f_i, f_e, f₀) must be adjusted. Techniques for determining f-values which can be used successfully for the purpose of obtaining reliable temperature-time relations at selected points within a tire have been discussed and illustrated by an example.

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Techniques for obtaining temperature-time relations at selected points within a slab and a tire, have been reported in Report No. 1 and Report No. 2, respectively. The final problem is to convert this tenperature-time curve into a measure of cure.
Techniques for calculating an “equivalent during time” -this may be defined as the time required at a selected constant temperature to give the same degree of cure as that given by the tenperature-time relationship under consideration. -from temperature-time curve to measure the degree of cure have been described in this paper,

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