%0 Artikel %@ 1022-1352 %A Kricheldorf, H.R. %A Lossow, C.v. %A Schwarz, G. %A Fritsch, D. %D 2005 %J Macromolecular Chemistry and Physics %N 1282 %P 1165 - 1170 %R doi:10.1002/macp.200400509 %T Chain Extension and Cyclization of Telechelic Polysarcosines %U http://dx.doi.org/10.1002/macp.200400509 %X Sarcosine N-carboxyanhydride (Sar-NCA) was polymerized with 1,12-diaminododecane (DAD) or 1,13- diamino-4,7,10-trioxatridecane (DATT) as initiators, and telechelic blocks having two secondary amino endgroups were obtained. Their structure was proven by 1H NMR and MALDI-TOF mass spectrometry. The SEC measurements indicated narrow molecular weight distribution with polydispersity indices in the range of 1.1–1.2. These difunctional polysarcosines were reacted with three different coupling agents: 4,40-diisocyanatodiphenylmethane (MDI), N-hydroxysuccinimide sebacate, and sebacoyl bisimidazolide. Although the 1H NMR spectra proved high conversions, only a moderate chain extension was observed. The MALDI-TOF mass spectra indicated a high extent of cyclization, which limited the chain growth.