Fluorescence studies of the hybrid composite of segmented-polyurethane and silica

In this work, we describe a new type of composite material made from segmented-polyurethanes and silica. The silica is incorporated into a hard segment phase of the segmented polyurethane to make a "hybrid domain". The composite formation between segmented polyurethane and silica was prepared via a general sol-gel process. The fluorescence emission spectra from dansyl probe molecules bonded to the silica gave us information about crystallization behavior of the hard segments in the hybrid domain. According to the emission signals from the probe, the rearrangement temperatures (Tr) of the hard segments of 2,6-TDI polymer composites increased with increasing silica content from TDI polymer/silica 100:1 to 100:5, indicating that the silica associated with the HS domain hindered the HS from completing their rearrangement. The hybrid domains with the ratios of 100:10 and 100:30 retained the well-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.