Abstract: Melt processable halogen-free low smoke wire coating compositions are provided which utilize a polyimide-siloxane, an effective amount of a plasticizer and hydrated zinc borate. The melt processable halogen-free low smoke blends can satisfy the low smoke requirements for plenum wire as shown by an Ohio State University test value of total smoke after 5 minutes of less than 100.

Abstract: There is provided by the present invention aromatic polyester-siloxane block copolymers which can be made by effecting the condensation between tetramethyldisiloxane bisbenzoic acid or acid chloride with a dihydric phenol such as bisphenol A or in combination with a mixture of such tetramethyldisiloxane bisbenzoic acid and aromatic acids, such as terephthalic acid or isophthalic acid. The aromatic polyester-siloxane block copolymers can be used as molding compounds, extruded films, in making composite matrix materials and as flame retardants for aromatic polycarbonates.

Abstract: A method is provided for the acidic equilibration of aromatic organic-substituted siloxanes, such as diphthalic anhydrode tetraorganicsiloxane with poly(aliphatic organicsiloxane) without significant cleavage of carbon-silicon-bonded aromatic organic radicals. A reduction in the generation of aromatic organic compounds, such as phthalic anhydride, can be achieved by effecting equilibration by adding the aromatic organic-substituted siloxane to a preformed mixture of acid-catalyzed poly(aliphatic organicsiloxane).