Ralf Pakull

New polymer syntheses: 21. LC-poly(ester imide)s prepared from trimellitic acid, α,θ-diaminoalkanes and various hydroquinones or dihydroxynaphthalenes

Abstract A series of nine α,θ-diaminoalkane bistrimellitimides was prepared from trimellitic anhydride and these were then condensed with the acetyl derivatives of various bisphenols. These bisphenols included hydroquinone, methyl-, chloro-, phenyl- and tetrachlorohydroquinone, 1,5-, 1,4-, 2,7- and 2,6-dihydroxynaphthalenes. Only poly(ester imide)s containing hydroquinone and tetrachlorohydroquinone or 2,6-dihydroxynaphthalene formed a mesogenic melt. Compared with the corresponding poly(ester imide)s built up from 4,4′-dihydroxybiphenyl, the melting points were lower and the temperature range of the mesogenic melt was significantly smaller. WAXS measurements of the solid materials indicated a layered structure with a periodicity corresponding to the length of the monomer units. The poly(ester imide)s were characterized by elemental analyses, viscometry, d.s.c. measurements, polarizing microscopy and thermogravimetric analyses. Furthermore, heat-distortion temperatures were measured under high and low pressure. Most poly(ester imide)s with an even number of methylene groups exhibit heat distortion temperatures close to the melting point, whereas those with an odd number display heat distortion temperatures close to the glass transition.

Thermotropic Polyesterimides Derived From Trimellitic Acid

Abstract Two groups of thermotropic poly(ester-imide)s were prepared from trimellitic anhydride (TMA) and various bisphenols. The first group contains α, w-di- amines the second group w-amino acids as flexible spacers. Both groups possess a layered supermolecular structure in the solid state and form a smectic melt above the melting points. The poly(ester-imide)s with diamine spacers possess a regular primary structure, they crystallize rapidly and reach a high degree of crystallinity. Furthermore, they show unusually high heat distortion temperatures (HDTs) which are directly related to their melting points.