LC-polyimides XXXIV. Noncrystalline thermotropic copoly(ester-imide)s based on PET

New polymer syntheses. 102. Aspirin-modified LC polyesters based on PET and 4-hydroxybenzoic acid

“…In a qualitative sense, these maxima do not depend on the frequency of the measurements. Furthermore, the same trends have recently been observed6 for noncrystalline nematic copoly(ester imide)s. Therefore, it may be concluded that the positive influence of SA on the melt strength of LC copolyesters has a broader validity. The consequences of this SA effect for the processing of LC polyesters are currently under investigation, and a patent claim has been submitted.…”

“…The molecular weights of these poly(ester imide)s were low, presumably because of the formation of macrocyclic oligomers. Furthermore, it has recently been observed for another class of LC poly(ester imide)s (Structure 2) that even a high content of salicylic acid (SA) does not eliminate the thermotropic properties 6. These findings prompted us to study in this work the influence of SA on the properties of LC polyesters derived from poly(ethylene terephthalate) (PET) and 4‐hydroxybenzoic acid (4‐HBA).…”

“…However, the presence of entanglements may improve the melt strength, toughness, and film‐forming properties of LCPs. With the exception of our parallel work on SA‐containing poly(ester imide)s,6 no studies in this direction have been published so far. …”

Synthesis, Characterization and Properties of Poly(butylene succinate) Reinforced by Trimellitic Imide Units

“…Polyimides are one of the most important commercial polymers because of their good thermal properties and mechanical properties 17,18. To our knowledge, the combination of polyesters and polyimides has achieved great success and yielded a series of new materials with high performance 19–23.…”