scholarly journals Mechanical, thermal and surface properties of polyacrylamide/dextran semi-interpenetrating network hydrogels tuned by the synthesis temperature

2013 ◽  
Vol 11 (2) ◽  
pp. 248-258 ◽  
Author(s):  
Maria Dinu ◽  
Maria Cazacu ◽  
Ecaterina Drăgan
Keyword(s):  
Thermal Stability ◽  
Polymer Network ◽  
Synthesis Temperature ◽  
Water Vapor Sorption ◽  
Interpenetrating Polymer Network ◽  
Vapor Sorption ◽  
Interpenetrating Network ◽  
Preparation Temperature ◽  
Thermal Stability Of ◽  
Network Morphology

AbstractThe mechanical, rheological, thermal, and surface behaviors of three polyacrylamide/dextran (PAAm/Dx) semi-interpenetrating polymer network (semi-IPN) hydrogels, prepared at 22°C, 5°C and −18°C, were investigated. The results were compared with those obtained on cross-linked PAAm without Dx synthesized under the same conditions. Hydrogels prepared at the lowest temperature were the most mechanically stable. The thermal stability of the semi-IPN hydrogels is slightly lower than the corresponding PAAm gels, irrespective of preparation temperature. The water vapor sorption capacity depended on the presence of Dx as well as preparation temperature, which determines the network morphology.

Designing of Biodegradable Interpenetrating Polymer Network of Poly(vinyl alcohol-co-acrylic acid)/sodium chloride hydrogel : An Approach to Drug Delivery

1970 ◽  
Vol 1 (2) ◽  
pp. 144-151
Author(s):  
Debajyoti Ray ◽  
Prafulla Kumar Sahoo ◽  
Guru Prasad Mohanta
Keyword(s):  
Drug Delivery ◽  
Thermal Stability ◽  
Sodium Chloride ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Poly Vinyl Alcohol ◽  
Electron Microscopic ◽  
Swelling Properties ◽  
Scanning Electron Microscopic Study ◽  
Thermal Stability Of

Interpenetrating polymer network (IPN) hydrogel based on polyvinyl alcohol (PVA) networking with polyacrylic acid (PAA), generated insitu, were prepared by without any added crosslinker, using benzoyl peroxide an initiator and sodium chloride (NaCl) as additive. The response of the hydrogels with and without NaCl was observed by studying their swelling behavior, biodegradability and thermal stability. Scanning electron microscopic study revealed that the pores of the prepared IPN were mostly open in presence of NaCl, thus making the hydrogel macroporous. (PVA-co-PAA)/NaCl was found to be more biodegradable than without NaCl. The IPN hydrogel showed comparatively higher swelling at intestinal pH than that of gastric medium and presence of NaCl in the IPN increases the swelling properties in both media. Thermal stability of IPN was affected by copolymerization, due to increasing porosity of the IPN. The prepared nontoxic, hydrophilic IPN hydrogel system holds good for further drug delivery studies in connection to its superswelling and biodegradablity.

Effect of Cenosphere on the Performance of Polyurethane/Polystyrene Interpenetrating Polymer Network Green Composites

2017 ◽  
pp. 158-185
Author(s):  
Roopa S. ◽  
Siddaramaiah
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
Thermogravimetric Analysis ◽  
Castor Oil ◽  
Polymer Network ◽  
Thermal Characteristics ◽  
Mechanical Analysis ◽  
Interpenetrating Polymer Network ◽  
Toluene Diisocyanate ◽  
Green Composites

The effect of cenosphere content on the performances of polyurethane/polystyrene (PU/PS, 90/10) interpenetrating polymer network (IPN) based green composites have been studied. The PU/PS IPNs have been prepared using castor oil, toluene diisocyanate and styrene. IPN/cenosphere composites have been prepared with different weight fractions viz., 0, 5, 10, 20 and 30 wt % of cenosphere. The prepared IPN composites have been characterized by physico – mechanical, chemical and thermal behavior. The tensile strength of unfilled IPN was 1.79 MPa and a significant improvement in tensile strength (34%) was noticed for 10% cenosphere loaded IPN composite. The swelling behavior of the composites has been studied in different organic solvents. Thermal characteristics of the composites have been measured using differential scanning calorimeter, thermogravimetric analysis and dynamic mechanical analysis (DMA). A slight improvement in thermal stability was noticed for filler loaded specimens. Morphological features of cryo-fractured IPN/cenosphere green composites have been analyzed using SEM.

Development of visible-light responsive and mechanically enhanced “smart” UCST interpenetrating network hydrogels

Soft Matter ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 151-160 ◽  
Author(s):  
Yifei Xu ◽  
Onkar Ghag ◽  
Morgan Reimann ◽  
Philip Sitterle ◽  
Prithwish Chatterjee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Visible Light ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Solution Temperature ◽  
Interpenetrating Network ◽  
Critical Solution Temperature ◽  
Smart Hydrogel ◽  
Upper Critical Solution Temperature

An interpenetrating polymer network, chlorophyllin-incorporated “smart” hydrogel was synthesized and exhibited enhanced mechanical properties, upper critical solution temperature swelling, and promising visible-light responsiveness.

scholarly journals Rheological and thermal stability of interpenetrating polymer network hydrogel based on polyacrylamide/hydroxypropyl guar reinforced with graphene oxide for application in oil recovery

2021 ◽  
Vol 41 (9) ◽  
pp. 788-798
Author(s):  
Amir Narimani ◽  
Farid Kordnejad ◽  
Prabhjyot Kaur ◽  
Saeed Bazgir ◽  
Mahmood Hemmati ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Oil Recovery ◽  
Polymer Network ◽  
High Viscosity ◽  
Interpenetrating Polymer Network ◽  
Flow Activation Energy ◽  
Nanocomposite Hydrogels ◽  
Hydroxypropyl Guar ◽  
Hydrogel Matrix

Abstract The purpose of the present work is to enhance the thermal stability and rheological properties of semi-interpenetrating polymer network (IPN) hydrogel based on partially hydrolyzed polyacrylamide/hydroxypropyl guar (HPAM/HPG) nanocomposite reinforced with graphene oxide (GO), at temperatures (200 and 240 °F) for use in oil recovery applications. FTIR spectra of the IPN nanocomposite hydrogels revealed interactions of GO with HPAM/HPG chains. An increase in the viscosity is also observed from the rheological study. Moreover, IPN and its nanocomposite hydrogels exhibited non-Newtonian behavior. The decline of viscosity of IPN nanocomposite hydrogels was observed with an increase in the temperature from 200 to 240 °F but was still higher than IPN hydrogel without GO. Dispersion of GO through the HPAM/HPG hydrogel matrix was evaluated by SEM morphology and electrical conductivity. The IPN nanocomposite hydrogels showed high viscosity stability, thermal stability, and flow activation energy as compared to IPN hydrogel without GO. Therefore, the addition of 0.1 wt.% of GO to the HPAM/HPG matrix is suitable to create a cross-linked polymer solution with improved properties which may be beneficial for use in oil recovery applications.

scholarly journals Effects of (complementary) Polyelectrolytes Characteristics on Composite Calcium Carbonate Microparticles Properties

2017 ◽  
Vol 54 (4) ◽  
pp. 708-714
Author(s):  
Cristian Barbu Mic ◽  
Marcela Mihai ◽  
Cristian Dragos Varganici ◽  
Simona Schwarz ◽  
Dan Scutaru ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Calcium Carbonate ◽  
Polymer Network ◽  
Weight Ratio ◽  
Crosslinking Density ◽  
Molar Ratio ◽  
Polyelectrolyte Complexes ◽  
Supersaturated Solutions ◽  
Thermal Stability Of ◽  
Flow Particle

This study follows the possibility to tune the thermal stability of some CaCO3/polymer composites by crystal growth from supersaturated solutions controlled by polymer structure or by using nonstoichiometric polyelectrolyte complexes (NPECs). As the ratio between the organic and inorganic parts in the composites controls the Ca2+/polymer network crosslinking density, the CaCO3/polymer weight ratio was kept constant at 50/1, varying the initial concentration of the polyanions solutions (0.05 or 0.06 wt.%), the NPECs molar ratio , n+/n- (0.2 or 0.4), or the inorganic precursors concentration (0.25 or 0.3 M). Poly(2-acrylamido-2-methylpropanesulfonic acid-co-acrylic acid) (PSA) and chondroitin-4-sulfate (CSA) were used as polyanions. Some NPEC dispersions, prepared with the same polyanions and poly(allylamine hydrochloride) (PAH), were also used for calcium carbonate crystallization. The characteristics of the prepared composites were investigated by scanning electron microscopy (SEM), flow particle image analysis (FPIA), particles charge density (CD), zeta-potential (ZP). The thermal stability of the composite particles was investigated as compared to bare CaCO3 microparticles prepared at the same initial inorganic concentrations.

scholarly journals Swelling Behavior and Drug Release of Interpenetrating Network Composed of PVA and Chitosan

2018 ◽  
Vol 31 (1) ◽  
pp. 145
Author(s):  
Fathel S. Matty ◽  
Zainab M. MohiALDeen
Keyword(s):  
Electron Microscope ◽  
Drug Release ◽  
Polymer Network ◽  
Structure Characterization ◽  
Interpenetrating Polymer Network ◽  
Biocompatible Polymers ◽  
Interpenetrating Network ◽  
Morphology And Structure ◽  
Uv Visible ◽  
Scanning Electron

     PVA and chitosan biodegradable, non-toxic, biocompatible polymers convenient for use in drug release. In this study polyvinyl alcohol (PVA) and chitosan (CS) hydrogels crosslinked with glutaraldehyde (GA) with different ratio morphology and structure characterization interpenetrating polymer network (IPN).They were investigated by Fourier transmission infrared spectroscopy (FTIR), scanning electron microscope (SEM), UV-Visible spectrophotometer,swelling of hydrogel and drug release were studied by changing crosslinking ratio and PH.  

scholarly journals The influence of stereochemistry on the reactivity of the Diels–Alder cycloaddition and the implications for reversible network polymerization

2019 ◽  
Vol 10 (4) ◽  
pp. 473-485 ◽  
Author(s):  
Audrey Cuvellier ◽  
Robrecht Verhelle ◽  
Joost Brancart ◽  
Bram Vanderborght ◽  
Guy Van Assche ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Polymer Network ◽  
Diels Alder ◽  
Thermal Stability Of

The differences in reactivity and thermal stability of the stereoisomers define the thermal properties and responsiveness of the reversible polymer network.

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