ABSTRACT
Thiourethane Sealants .................................................................. 221 5.4 Compositions Based on Liquid Thiokol and Bitumen ................. 230 Keywords .............................................................................................. 249 References ............................................................................................. 249
5.1 THE INFLUENCE OF THIXOTROPIC ADDITIVES ON THE PROPERTIES OF SEALANTS
Thixotropicity, that is sealant’s resistance to flowing down a vertical surface, is one of the main technological properties, required from sealants designed for sealing of interpanel joints in house building, which stipulates their application capabilities. [1]. The viscosity and thixotropicity of compositions based on high molecular weight polymers or oligomers of various nature is known to be increased by addition of silica, montmorillonites (bentonites) as well as by such hydroxyl-containing compounds as ethylene glycol (EG) and glycerol [2-4]. However, there is no systematic research in the selection of additives and their influence on viscous and thixotropic properties. Therefore, a study has been carried out concerning the influence of silica (aerosils A-175 and A-300, carbon white BS120 and caoline) and various glycols (water, EG, diethyleneglycol (DEG), glycerol) on the viscous and thixotropic properties of filled (natural chalk –100 mass parts) and unfilled sealants based on thiokol-containing oligomer (TPM-2 polymer) and liquid thiokol. These sealants were cured by manganese dioxide. Oxidant’s excess coefficient (in moles) was 3 in relation to end SH-groups.
