STUDIES ON THERMAL BEHAVIOUR OF TETRAALKOXYSILANES
Titel:
STUDIES ON THERMAL BEHAVIOUR OF TETRAALKOXYSILANES
Auteur:
Alagar, M. Krishnasamy, V.
Verschenen in:
Chemical engineering communications
Paginering:
Jaargang 80 (1989) nr. 1 pagina's 1-9
Jaar:
1989-06-01
Inhoud:
Tetraalkoxysilanes (Compounds A to O) were prepared by reacting SiCI4 with corresponding alcohols in the liquid phase in the presence of pyridine as acid acceptor in benzene solvent. Based on the experimental evidences and theoretical calculations tentative structures had been proposed. Properties such as density, refractive index, viscosity, surface tension, molecular weight, thermal expansion, specific heat, thermal conductivity, decomposition temperature and oxidation stability were determined. Prandtl number, Reynold's number and heat transfer coefficient for tetraalkoxysilanes were calculated and were compared with those of coolanols of Monsanto Chemicals, USA. Thermal stability of the compounds was studied by heating them at 200°C for 100 hours in the presence and in the absence of phenyl-a-naphthylamine and diphenylamine as stabilizers and redetermining some of the properties like density, refractive index, surface tension, viscosity and molecular weight The variation of the properties due to heat treatment is less significant when they are heated in the presence of a stabilizer. The low variation of physical constants by heat treatment particularly in the presence of a stabilizer suggests that these compounds are thermally stable and can be used in heat transfer and other thermal applications with stabilizers
Tijdschrift beschrijving