Morphology and phase separation in PTT-block-PTMO nanocomposites containing POSS particles

Abstract This work is aimed at determining the effect of polyhedral oligomeric silsesquioxanes (POSS) on the microstructure and phase separation of PTT- block -PTMO based nanocomposites, which were prepared by the means of in situ polymerization. Scanning electron microscopy images (along with EDS analysis) confirmed the occurrence of the reaction between the (n-octyl)dimethylsiloxy groups of POSS and functional groups of PTT- block -PTMO copolymer during in situ polymerization, which leads to the formation of excellent dispersed POSS nanoparticles with good interfacial adhesion. The results showed that the addition of POSS affected the crystallization of the PTT rich phase. The DSC results imply that POSS cages in PTT- block -PTMO act as anti-nucleation agents and inhibit the crystallization of PTT hard phase during the cooling down process from the melt shifting crystallization temperature toward lower values. The introduction of POSS does not have great effect on the glass transition temperature of PTMO-rich soft phase, melting temperature of PTT hard phase and degree of crystallinity of the nanocomposites. Moreover, the influence of the presence of nanoparticles on the phase separation of polymer matrix has been observed.