Synthesis of Single-Component Hybrid Urethane Sealants with a Built-in Catalyst

Abstract

The use of dimethylolpropionic acid (DMPA) as an integrated catalyst in the prepolymer chain in the synthesis of silanized polyurethanes is proposed. The effect of DMPA concentration and synthesis conditions on the viscosity of the prepolymer in the synthesis of silanized polyurethanes (SPU), on their curing rate and physical and mechanical indicators is investigated. The viscosity of the prepolymer was carried out on a rotary viscometer Alpha of the company «Fungilab». The rest of the studied indicators were determined by standard methods. It was found that with the single-stage method, the viscosity of the obtained prepolymer is lower than with the two-stage method and increases with increasing DMPA concentration. Also, with an increase in the concentration of DMPA, the formation time of the surface film decreases, and the degree of curing in the mass of the SPU increases. An increase in the salt concentration obtained on the basis of the built-in DMPA accelerates the formation of a surface film, as well as DMPA, but curing occurs faster. With a two-stage method of administration of DMPA and its salt, the inverse dependence is observed in the structure of the SPU. The physical and mechanical indicators of the obtained sealants improve with an increase in the catalyst. With a single-stage method of administration of DMPA and its salt, these indicators are higher than with a two-stage one.