Gradient semi-interpenetrating polymer networks based on polyurethane and poly(vinyl pyrrolidone)

2005 ◽  
Vol 15 (4) ◽  
pp. 499 ◽  
Author(s):  
Lyudmila V. Karabanova ◽  
Sergey V. Mikhalovsky ◽  
Andrew W. Lloyd ◽  
Gisele Boiteux ◽  
Lyudmila M. Sergeeva ◽  
...  
2018 ◽  
Author(s):  
Fereshteh Shokri ◽  
Pouneh Ebrahimi ◽  
Soheyla Honary

AbstractHydrogels are three-dimensional crosslinked hydrophilic polymer networks capable of swelling or de-swelling reversibly in water and retaining a large volume of liquid in swollen state. Hydrogels can be designed with controllable responses to shrink or expand with changes in external environmental conditions. Among stimulisensitive hydrogels, the pH-sensitive ones are widely-studied and used. Despite these advances, we currently lack a systematic way to optimize the synthesis protocols. Here we propose to use techniques from chemometrics, namely Box–Behnken statistical screening design to optimize the chemical composition of pH-responsive hydrogels for an improved responsiveness as quantified by swelling index. Polymer blends were prepared by mixing different suitable volume of pvp (poly vinyl pyrrolidone) and chitosan aqueous solution in order to obtain a mixture, glutardialdehyde solution was added as crosslinkers to the chitosan/pvp mixture to form semi-IPN(semi-interpenetrating polymeric hydrogel). The pH-dependent swelling properties have been measured and used to obtain a regression model. We characterized the descriptive and predictive abilities of our model. We found a remarkable correlation (correlation coefficient = 0.954) between the observed responses and the responses predicted by the model. Our results demonstrate that Box-Behnken is an appropriate statistical design that can be successfully used in the development of pH-sensitive hydrogels with a predictable swelling ratio. This technology will remarkably reduce the time and cost that is needed for chemical synthesis of hydrogels with a desired pH-sensitivity.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Aazadehsadat Hashemi Doulabi ◽  
Hamid Mirzadeh ◽  
Nasrin Samadi ◽  
Shadab Bagheri-Khoulenjani ◽  
Mohammad Atai ◽  
...  

The objective of this work was to prepare hydrogel films, as semi-interpenetrating polymer networks (semi-IPN), based on polyethylene glycol-co-fumarate (PEGF) and chitosan (Ch) blends. Hydrogel films were prepared by free radical cross-linking of PEGF, an unsaturated aliphatic polyester, in the presence of N-vinyl pyrrolidone (NVP), camphorquinone (CQ), and N,N-dimethyl-p-toluidine (DMPT) as a cross-linking, photoinitiating, and accelerating agent, respectively. The effect of NVP concentration on physicochemical and biological properties of semi-IPN film properties was evaluated. The sol fraction, water vapor transmission rate, and swelling degree of the hydrogel films were also investigated. Antibacterial activity against S. aureus was observed for the photocured blend hydrogels of Ch/PEGF with no toxicity to L929 cells according to the cell viability assays. Blend hydrogel films showing 600 ± 88% of equilibrium swelling degree in water and the lowest sol fraction (3.14 ± 1.22%) were obtained at 20 wt% of NVP content whilst preserving their own cytocompatibility and antibacterial activity. Therefore, this formulation was considered as an optimal semi-IPN blend hydrogel film composition with potential application for wound dressing.


Polymer ◽  
2021 ◽  
Vol 224 ◽  
pp. 123671
Author(s):  
Gregory N. Smith ◽  
Erik Brok ◽  
Martin Schmiele ◽  
Kell Mortensen ◽  
Wim G. Bouwman ◽  
...  

2021 ◽  
Author(s):  
Martina Rihova ◽  
Oksana Yurkevich ◽  
Martin Motola ◽  
Ludek Hromadko ◽  
Zdeněk Spotz ◽  
...  

This work describes the synthesis of highly photocatalytically active TiO2 tubes (TiTBs) by combining centrifugal spinning and atomic layer deposition (ALD). Poly(vinyl pyrrolidone) (PVP) fibers were first produced by centrifugal...


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