H. Kricheldorf, R. Hobzova, L. Vakhtangishvili
Apr 23, 2005
Citations
1
Influential Citations
20
Citations
Journal
Macromolecules
Abstract
2,6,4‘-Trifluorobenzophenone (TFB) was polycondensed with silylated 4,4‘-dihydroxybiphenyl (DHBP) or silylated bisphenol A in N-methylpyrrolidone by means of K2CO3 as catalyst and HF acceptor. At constant concentration (0.08 mol/L) the feed ratio was varied from 1.0/1.0 to 1.0/1.5. For polycondensations of DHBP cross-linking was observed for feed ratios above 1.0/1.1, whereas no gelation occurred with bisphenol A regardless of the feed ratio. The MALDI−TOF mass spectrometry proved the formation of cyclic, bicyclic and multicyclic oligomers and polymers in all cases. At a feed ratio of 1.00/1.48, multicyclces free of functional (end)groups were the only reaction products. However, gelation was only avoided when the initial concentration of TFB was lowered to 0.04 mol/L. Under these optimized conditions three more diphenols resembling bisphenol A were polycondensed with TBP and multicycles free of functional groups were again obtained as predominant reaction products. SEC measurements proved the formation o...