Structure–property co‐relationship of fluorinated poly(imide‐siloxane)s

Eight poly(imide‐siloxane)s co‐polymers have been prepared by one pot solution imidization method. The polymers are synthesized by the reaction of bisphenol‐A‐dianhydride (BPADA) with fluorinated diamine 4,4′‐bis(3″‐trifluoromethyl‐p‐aminobiphenyl ether) biphenyl, and aminopropyl‐terminated polydimethylsiloxane (APPS). The polymers are synthesized by varying the siloxane loading to 5, 10, 15, 20, 25, 30, 35, and 40 wt%, respectively. Thermal, mechanical, rheological, and dielectric properties of these polymers have been evaluated with respect to siloxane loading. The polymers showed glass transition temperature of 107–203°C and tensile strength at break of 24–75 MPa depending on siloxane loading. The elongation break of the polymers ranges from 24 to 144% depending on siloxane loading. The amounts of char residue in the polymers have been correlated with incorporated siloxane in the polymer by NMR techniques. The polymers showed very low water absorption and dielectric constant as low as 2.43 when the siloxane loading is 40 wt%. Copyright © 2008 John Wiley & Sons, Ltd.