title: Cationization of heparin for film applications.
abstract: Trimethylammonium-2-hydroxypropyl-(TMAHP) spacer was introduced into heparin (H) and the prepared films were characterized by elemental analysis, NMR, SEC-MALS, TG/DTG/DTA, AFM and mechanical tester. When quaternized at the ratio of H/NaOH/alkylating agent/H2O=0.1-1/0-2/0.1-1/50-500 mmol, H was substituted at A6 and A3 positions. The formation of double-substituted structures by substitution of free hydroxyl group of the previously introduced TMAHP substituent is evident. In the absence of NaOH (H/GTMAC/H2O=1:1:500) the most drastic decrease of M(n) to 8.639 kg/mol and M(w)/M(n) at 1.48 was observed in comparison to H (Mn=9532 g/mol with M(w)/M(n)=1.38). The film mechanical properties were better on H (E=4030 MPa; σ(b)=65 MPa; ɛ(b)=4.6%) than on quaternized specimens (E=2500-3340 MPa; σ(b)=25-40 MPa; ɛ(b)=1.7-1.8%). The AFM images did not prove relation between mechanical properties and surface shape.
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, 845 38 Bratislava, Slovakia. Electronic address: chemsimk@savba.sk.
authors.forename: Ivan
authors.initials: I
authors.lastname: Simkovic
authors.affiliation: Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, 20133 Milan, Italy.
authors.forename: Raniero
authors.initials: R
authors.lastname: Mendichi
authors.affiliation: Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Square 2, 162 06 Prague, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Kelnar
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, 845 38 Bratislava, Slovakia.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Filip
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, 845 38 Bratislava, Slovakia.
authors.forename: Miloš
authors.initials: M
authors.lastname: Hricovíni
mesh_terms: D006493:Heparin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*
chemical_list: D000644:Quaternary Ammonium Compounds; D006493:Heparin
keywords: Cationization; Films; Heparin; NMR; SEC-MALS; TG/DTG/DTA