Structure and Properties of the POSS-Containing Nanocomposites Based on Polyurethane Matrix

Abstract

Nanocomposites based on Polyurethane (PU) matrix and 1,2-propanediolisobutyl-POSS (POSS) nanoparticles were prepared and investigated. POSS nanoparticles were incorporated into PU matrix in the process of PU synthesis. The structure peculiarities, the dynamic mechanical and thermal properties, the morphology of the nanocomposites have been investigated. Overall, it was found that POSS nanoparticles are capable to be incorporated into PU polymer chain by a chemical reaction between hydroxyl groups of POSS and diisocyanate groups of PU. The incorporation of the POSS nanoparticles into PU matrix leads to the formation of a more ordered structure, the POSS acts as a nanostructuring agent in the system. The introduction of the POSS nanoparticles into PU matrix significantly affects the thermal properties of the nanocomposites: the increasing in thermal stability was found. Investigation by WAXS/SAXS methods has shown that nanofiller POSS slightly affects the amorphous structure of PU. However, to a greater extent, the nanofiller POSS affects the microphase structure of PU. By dynamic mechanical analysis, it was detected that the storage moduli of PU/POSS nanocomposites exceeds the storage modulus of PU. But Mn/Mo changes non-monotonically with POSS content. The storage modulus of the nanocomposites increases in 1, 5 times compared to the native PU for the nanocomposites contained from 1 to 5 wt% of POSS. From the morphology investigation, it is obvious that POSS introduced into PU matrix acts as nanostructuring agent. As a result, the nanocomposites with more ordered structure are formed thus leading to materials with improved thermal stability.