Based on Bis-MPA

Similar materials, hyperbranched polyesters based on bis-MPA and a polyol are now commercially available [11] from Perstorp AB under the trade name Boltorn [12], Figure 8.1. The average number of hydroxyl groups per molecule can be tailored between 8 and 64 and molecular weight can be varied between c. 2000 and 11 000. The co-polymerization of bis-MPA and a polyol core keeps the molecular weight distribution fairly low, typically below 2. 

The question of whether it was possible to increase the efficiency even further was investigated next by having as many chromophores as possible close to each other, to promote intramolecular cycloaddition. In this case, it should not be necessary to find another monomer lying around per chance for dimerization. The obvious choice of backbone in this case was adendrimer. Two series of uracil-functionalized dendrimers based on bis-MPA and PAMAM were looked into. Dendrimers up to fourth generation were synthesized and their dimerization efficiency compared with both peptide and... 

Fig. 2. Hyperbranched polyester based on bis-MPA and a polyol, commercially available from Perstorp AB (http //www.perstorp.com) under the trade name Boltorn.

Fig. 11. Melt viscosity at 85 °C vs molar mass for hydroxy-functional hyperbranched aliphatic polyesters based on bismethylol propionic acid. Theoretical molar mass based on core bis-MPA ratio ( ) and Mn determined with SEC relative to linear polystyrene standards (O) [117]...

The first part of this review deals with the synthesis and characterization of dendritic aliphatic polyesters based on 2,2-bis(dimethylol)propionic acid (bis-MPA) and 1,1,1 -tris(hydroxyphenyl)ethane (THPE), as core molecule. The convergent growth approach described earlier was applied. We also present H NMR self-diffusion studies of dendrimers of first, second, and third generation. 

First, second, and third generation dendrimers based on THPE (core) and bis-MPA (repeating unit) have been synthesized and characterized. SEC and NMR analyses verified that the dendrimers were monodisperse. Diffusion NMR was used to determine the dendrimers hydrodynamic radii in deuterated chloroform. First, second, and third generation dendrimers were found to be 7.8, 10.3, and 12.6 A, respectively. These were in agreement with sizes as determined from molecular models (Biichi). 

DENDRIMERS AND HYPERBRANCHED ALIPHATIC POLYESTERS BASED ON 2,2-Bis(HYDROXYMETHYL)PROPIONIC ACID (Bis-MPA)... 

Well-defined aliphatic polyesters and dendrons based on 2,2-bis(methylol)pro-pionic acid (bis-MPA) are commercially available from the Swedish company Polymer Factory. Their stability on storage, solubility, and low toxicity make them attractive for the medical sector. 

Dendrimers and Hyperbranched Aliphatic Polyesters Based on 2,2-Bis(hydroxyme-thyl)propionic Acid (bis-MPA) [H. Ihre, M. Johansson, E. Malmstrom, A. Hult, Chapt. 3],... 

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