No abstract

No abstract

The properties of star-shaped adamantane multipodes with different types of rigid branches with various lengths are discussed. The expectation based on theoretical considerations was that such multipodes would display an enhanced solubility both in low molar mass solvents and in polymer matrices. These multipodes have a three-dimensional star-like shape, are able to crystallize but can also be obtained in the glassy state, and they show a relaxational behavior typical for polyarylates. They are soluble in various low molar mass organic solvents much better than linear rigid molecules of the same chemical constitution and of similar length and they are miscible in polymer matrices up to concentrations of 30 wt%. The multipodes were found to influence the dielectric and mechanical properties of the matrix polymers significantly.

The influence of the chemical structure of rigid star‐shaped multipodes composed of an adamantane central core and short rigid branches on the glass formation and crystallisation is analysed. It was found that esters of 1,3,5,7‐adamantanetetracarboxylic acid with various phenols (3a–c) and esters of 1,3,5,7‐tetrahydroxyadamantane with various benzoic acid derivatives (4a–c) display both crystalline and glassy states with high glass transition temperatures and melting temperatures. These quantities strongly depend on the restriction of the rotational motions about the ester groups connecting the core and the branches.

The synthesis of star‐shaped adamantane multipodes with rigid branches based on p‐hydroxybenzoic acid is reported. These multipodes are able to crystallize but can also be obtained in the glassy state. They are soluble in various low molar mass organic solvents, in fact, much better than linear rigid molecules of similar length, and they are miscible in polymer matrices up to concentrations of 30 wt%. The multipodes were found to influence the dielectric and mechanical properties of the polymers significantly.