“…Unsubstituted poly-C-vinyltetrazoles manifest acidic properties and enter into interpolymeric reactions with natural highmolecular-weight compounds, which determines their anticoagulant properties. 181,182 The anticoagulant activity can be varied significantly by combining structural fragments of vinyltetrazoles with other comonomers in the polymeric chain. 183,184 Quaternary salts of polyvinyltetrazoles exert an opposite effect: they bind heparin in the circulating blood and thus favour blood coagulation.…”