The morphology of PSF—PDMS—PHS n segmented ternary copolymer has been investigated by DMA

TEM and SAXS techniques. It is shown that a complicated morphology was found for the microphase separated structure of PSF—PDMS—PHS n . The new morphology is considered to consist of continuous domains formed by honey comb framewords

which is PDMS phase

and disperse domains

which is PSF and PHS mixed phase with small PDMS particle inclusions. When the contents of PSF and PHS segments are equal

this structure occurs in 0.50 for the weight fractions of PDMS segment.It is clearly seen that the [PSF-PDMS-PHS]n has a distinct interface phase.The boundary phase should be a mixture of the PDMS

PSF and PHS segments.