2. Experimental
2.1. Laboratory preparation of Alkanolamide
The reaction was carried out at atmospheric pressure in
a 1000 ml reaction vessel fitted with a stirrer. Typically,
1.0 mol of RBDPS and 3.0 mol each of diethanolamine, sodium
methoxide and methanol (as catalysts) were placed
in the reaction flask. The specifications of the RBDPS are
given in Table 1. The mixture was stirred and heated; the
reaction temperature was kept constant at 70 C for about
five hours. The resultant mixture was extracted with
diethyl ether, and washed with saturated sodium chloride
solution. The crude Alkanolamide was purified with
anhydrous sodium sulphate, and then concentrated by a
rotary evaporator. The final product, a cream-coloured,
waxy, solid material, namely Alkanolamide, was used as
an additive in silica-filled natural rubber compounds. The
reaction procedure was as shown in Fig. 1.