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Star‐shaped and hyperbranched polyesters
Author(s) -
Kricheldorf Hans R.
Publication year - 1997
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19971220105
Subject(s) - monomer , polyester , crystallinity , condensation polymer , branching (polymer chemistry) , polymer chemistry , materials science , amide , liquid crystal , solubility , benzoic acid , polymer , rheology , thermal stability , organic chemistry , chemistry , composite material , optoelectronics
In contrast to a‐a/b‐b type monomers, the a‐b monomers(e.g. hydroxy‐ or amino carboxylic acids) possess a much greater synthetic potential. Using 3‐ or 4‐hydroxy‐benzoic acid and 4‐hydroxyphenylpropionic acid (phloretic acid) starshaped polyesters with controlled molecular weight were prepared. Analogously, starshaped liquid‐crystalline copolyesters were synthesized, and the influence of star‐centers on the stability of the nematic phase was studied. Three polycondensation methods were elaborated and compared for the synthesis of hyperbranched homo‐ and copolyesters. Both the degree of branching and the nature of the endgroups were varied and their influence on the solubility, crystallinity and melt rheology was investigated. Furthermore, A‐B‐A triblock co‐polymers with hyperbranched A‐blocks, and hyperbranched poly(ester‐amide)s were synthesized and characterized.