%0 journal article
%@ 1022-1352
%A Kricheldorf, H.R.,Lossow, C.v.,Schwarz, G.,Fritsch, D.

%D 2005
%J Macromolecular Chemistry and Physics
%N 
%P 1165-1170 
%R doi:10.1002/macp.200400509
%T Chain Extension and Cyclization of Telechelic Polysarcosines
%U https://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.