Periodic system of homologous series of normal aliphatic hydrocarbons and compounds forming adducts with urea at temperatures of the upper limit of adduct formation

For more than three decades, we have conducted research in the nontraditional field of complexation of urea with normal aliphatic hydrocarbons and their derivatives containing oxygen, sulfur, nitrogen, or halogens at external temperatures. We have established that in addition to the traditional temperature interval of adduct formation (10-45 degrees C), systems consisting of an organic compound, urea, and the corresponding adduct typically have three external temperatures of the state of the system; the upper limit of adduct formation (ULA), the lower limit of decomposition of the adduct (LLD), and the upper limit of stability of the system (ULS). For several practical reasons, our studies were limited to the ULA region, and this paper reports the results of those studies.