Hellmuth Wurm

Organic/inorganic hybrids by ‘living’/controlled ATRP grafting from layered silicates

‘Living’/controlled radical graft polymerisation via the atom transfer radical polymerisation (ATRP) route has been carried out from ATRP initiator-modified layered silicate. The grafted polymer chains were detached from the solid in order to prove the well-known ATRP features. X-Ray diffraction measurements at different times of conversion demonstrate an increase of delamination as a result of increasing chain length of the grafts which finally results in a fully dispersed polymer silicate nanocomposite.

Bile Acids Bound to Polymers

SummaryBile acids are steroids containing one — lithocholic acid, two — desoxycholic acid, and three — cholic acid hydroxyl groups, respectively. The hydroxyl group in position 3 of the steroid skeleton after esterification of the carboxyl group at C-24 under suitable conditions selectively reacts with methacryloyl chloride to give the corresponding methacrylic ester derivatives which undergo radically initiated uni- and copolymerizations to yield high molecular weight polymers.

Influence of 2,2,6,6-tetramethylpiperidine and of 2,2,6,6-tetramethylpiperidine-N-oxide on radically induced styrene polymerization

SummaryThe influence of 2, 2, 6, 6-tetramethylpiperidine TMP and the corresponding N-oxide TEMPO on the kinetics of the radical polymerization of styrene in bulk is described. Results reveal that the piperidine TMP acts as a chain transfer agent with ctr=0.014 whereas TEMPO is a strong polymerization inhibitor. TEMPO is formed from TMP during polymerization in air saturated styrene.

Photosensitive polymers: I. Uni-and copolymerization behaviour of 1,3-bis-(4-benzoyl-3-hydroxyphenoxy)-2-propyl methacrylate

SummaryThe commercially available monomeric UV absorber 1,3-bis-(4-benzoyl-3-hydroxyphenoxy)2-propyl methacrylate readily undergoes radical uni- and Co polymerization to yield polymers which are in the chromophore UV absorbing region identical in regard to the monomer. The copolymerization parameters with styrone and MMA, respectively, were determined from 1H-n.m.r. and GPC measurements.