H. Kricheldorf, G. Loehden
Jun 1, 1995
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0
Influential Citations
16
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Journal
Macromolecular Chemistry and Physics
Abstract
The reaction of 3-acetoxybenzoyl chloribe (4) with N,N',O-tris(trimethylsilyl)-3,5-diaminobenzoic acid (5) proceeds by highly selective and almost quantitative acylation of both amino groups. The resulting 3,5-bis(3-acetoxybenzamido)benzoic acid (6 a), or its silylated derivative 6b, was polycondensed in bulk. The silylated monomer yielded the higher molecular weights. The condensation of 3,5-diacetoxybenzoyl chlorides with diamines containing aliphatic protons yielded acetylated tetraphenols which served as «star centers» for polycondensations. The polycondensation of silylated 3,5-bis(3-acetoxybenzamido)-benzoic acid (6b) with these «star centers» yieled in turn hyperbranched star polymers. The feed ratio of monomers and «star centers» allows the control of the molecular weight. 1 H NMR spectroscopy of these hyperbranched star polymers was used to betamine the average degree of polymerization (DP) and the average degree of branching (DB). 1 H and 13 C NMR spectroscopy also revealed that all polycondensations involve a significant extent of ester-amide interchange reactions