Improved synthesis of polystyrene-poly(ethylene oxide)-heparin block copolymers

Share/Save/Bookmark

Vulic, I. and Loman, A.J.B. and Feijen, J. and Okano, T. and Kim, S.W. (1990) Improved synthesis of polystyrene-poly(ethylene oxide)-heparin block copolymers. Journal of Polymer Science, Part A: Polymer chemistry, 28 (7). pp. 1693-1720. ISSN 0887-624X

[img]
Preview
PDF
1684Kb
Abstract:A novel procedure for the synthesis of block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic block of poly(ethylene oxide) and a bioactive block of nitrous acid-degraded heparin was developed. Amino-semitelechelic polystyrene was prepared by anionic polymerization of styrene in cyclohexane, using sec-butyllithium as initiator and N-(benzylidene)trimethylsilylamide as terminator. After purification using preparative column chromatography, polystyrene with one amino group per chain and a narrow molecular weight distribution was obtained. The terminal amino group was used in the coupling reaction with amino-telechelic poly(ethylene oxide) using toluene 2,4-diisocyanate to produce amino-semitelechelic polystyrene-poly(ethylene oxide) diblock copolymer (PS-PEO-NH2). The block copolymer was purified by preparative column chromatographic separations and had a narrow molecular weight distribution. Approximately one amino group per chain was found. When methylene 4,4-diphenyl diisocyanate or hexamethylene diisocyanate were used as coupling agents low yields of PS-PEO-NH2 were obtained. Polystyrene-poly(ethylene oxide)-heparin triblock copolymer was synthesized in a DMF-H20 (40:1, v/v) mixture by a coupling reaction of PS-PEO-NH2 with nitrous acid-degraded heparin, in which aldehyde groups react with the primary amino groups of PS-PEO-NH2 at pH 7 in the presence of NaBH3CN via reductive amination. Using this procedure, 18-32% w/w heparin was incorporated, corresponding to ±1 PS-PEO chain per heparin molecule. These procedures enable the synthesis of well defined heparin containing block copolymers, which will be further evaluated for thier blood compatibility.
Item Type:Article
Copyright:© 1990 Wiley InterScience
Faculty:
Science and Technology (TNW)
Research Group:
Link to this item:http://purl.utwente.nl/publications/70918
Official URL:http://dx.doi.org/10.1002/pola.1990.080280704
Export this item as:BibTeX
EndNote
HTML Citation
Reference Manager

 

Repository Staff Only: item control page