Rheological analysis of hybrid hydrogels during polymerization processes

Current Directions in Biomedical Engineering

Illner Sabine¹  Grabow Niels¹  Eickner Thomas¹  Sahmel Olga¹  Siewert Stefan² 

[1] Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde, Germany;Institute for Implant Technology and Biomaterials e.V. and Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde, Germany;

关键词: hydrogel;    crosslinking;    gelation;    n-vinyl-imidazolium;    polymeric ionic liquids;   

DOI  :  10.1515/cdbme-2017-0148

来源: DOAJ

【 摘 要 】

Development of new implant coatings with temperature-controlled drug release to treat infections after device implantation can be triggered by highly elastic hydrogels with adequate stability and adhesive strength in the swollen state. By using an ionic liquid (IL [ViPrIm]+[Br]−) as additive to N-isopropylacrylamide (NIPAAm) unique effects on volumetric changes and mechanical properties as well as thermoresponsive drug release of the obtained hybrid hydrogels were observed. In this context, rheological measurements allow the monitoring of gelation processes as well as chemical, mechanical, and thermal treatments and effects of additives. Hybrid hydrogels of pNIPAAm and poly (ionic liquid) (PIL) were prepared by radical emulsion polymerization with N,N′-methylenebis(acrylamide) as 3D crosslinking agent. By varying monomer, initiator and crosslinker amounts the multi-compound system during polymerization was monitored by oscillatory time sweep experiments. The time dependence of the storage modulus (G′) and the loss modulus (G″) was measured, whereby the intersection of G′ and G″ indicates the sol-gel transition. Viscoelastic behavior and complex viscosity of crosslinked and non-crosslinked hydrogels were obtained. Within material characterization rheology can be used to determine process capability and optimal working conditions. For biomedical applications complete hydrogelation inter-connecting all compounds can be received providing the possibility to process mechanically stable, swellable implant coatings or wound closures.

【 授权许可】

Unknown