Fluorescence studies of the hybrid composite of segmented-polyurethane andsilica

In this work, we describe a new type of composite material made from segmen ted-polyurethanes and silica. The silica is incorporated into a hard segmen t phase of the segmented polyurethane to make a "hybrid domain". The compos ite formation between segmented polyurethane and silica was prepared via a general sol-gel process. The fluorescence emission spectra from dansyl prob e molecules bonded to the silica gave us information about crystallization behavior of the hard segments in the hybrid domain. According to the emissi on signals from the probe, the rearrangement temperatures (Tr) of the hard segments of 2,6-TDI polymer composites increased with increasing silica con tent from TDI polymer/silica 100:1 to 100:5, indicating that the silica ass ociated with the HS domain hindered the HS from completing their rearrangem ent. The hybrid domains with the ratios of 100:10 and 100:30 retained the w ell-ordered structure similar to that of the original 2,6-TDI polymer above the crystallization temperatures (T-c), even when the SS matrix is frozen. The silica component destroyed the ordered structure of HS when the ratio of silica content in the hybrid domain exceeded the amount of HS.