Structure and swelling properties of polymer networks synthesized in solution

1992 ◽  
pp. 79-98
Author(s):  
Ferenc Horkay ◽  
Erik Geissler ◽  
Anne-Marie Hecht ◽  
Miklos Zrinyi
Keyword(s):  
Polymer Networks ◽  
Swelling Properties

Synthesis and swelling properties of pH- and temperature-sensitive interpenetrating polymer networks composed of polyacrylamide and poly(γ-glutamic acid)

2010 ◽  
Vol 119 (6) ◽  
pp. 3531-3537 ◽  
Author(s):  
D. E. Rodríguez-Félix ◽  
M. M. Castillo-Ortega ◽  
D. Real-Félix ◽  
J. Romero-García ◽  
A. S. Ledezma-Pérez ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Temperature Sensitive ◽  
Swelling Properties

Mechanical and swelling properties of PDMS interpenetrating polymer networks

Polymer ◽  
2006 ◽  
Vol 47 (17) ◽  
pp. 6226-6235 ◽  
Author(s):  
Seong Hyun Yoo ◽  
Claude Cohen ◽  
Chung-Yuen Hui
Keyword(s):  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Swelling Properties

scholarly journals Cross-Linked Polythiomethacrylate Esters Based on Naphthalene—Synthesis, Properties and Reprocessing

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3021
Author(s):  
Karolina Fila ◽  
Beata Podkościelna ◽  
Maciej Podgórski
Keyword(s):  
Polymer Networks ◽  
Polymeric Materials ◽  
Exchange Reactions ◽  
Scanning Calorimetry ◽  
Swelling Properties ◽  
Ene Reaction ◽  
Synthesis Properties ◽  
Double Bond Conversion ◽  
Swelling Studies ◽  
Synthesized Materials

Two structurally different aromatic dithioesters were synthesized from two dithiols and methacryloyl chloride. The polymer networks based on methyl methacrylate and/or styrene and the new dimethacrylates were subsequently prepared. The polymerization yields of copolymers were in the range of 95–99%. The thermal and mechanical properties of the copolymers were determined by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TG/DTG), and Shore D hardness. The addition of dithioesters—1,5-NAF-S-Met (or 1,4(1,5)-NAF-CH2S-Met) (from 0.5% to 5%) to MMA- or ST-based polymers results in lowering the glass transition temperature (Tg) by about 8 °C. The thioester-containing polymers based on MMA exhibit lower thermal stability than those with ST. The polythioesters are stable up to 250 °C. The UV/vis spectra and refractive indexes of prepared liquid compositions were also measured. The 1,5-NAF-S-Met (and 1,4(1,5)-NAF-CH2S-Met) improved the refractive index values of ST and MMA compositions. The double bond conversion was also determined for all synthesized materials. The swelling studies of polymers with 20% addition of thioester crosslinkers were investigated. For all polymeric materials with 20% addition of thioesters, depolymerization of the network was carried out by thiol-thioester exchange. The depolymerization products were re-reacted in a thiol-ene reaction with 2-hydroxyethyl methacrylate by thermal initiation. The thiol-ene procedure enabled reprocessing of starting polymers and obtaining new materials characterized by distinctly different thermal, mechanical, and swelling properties. The thiol-ene materials exhibit a lower Shore hardness in the range of 20–50 °Sh, as well as decreased Tg values when compared to starting copolymers. Due to these possible exchange reactions, one can facilely manipulate the properties of the polymers which could lead to the manufacturing of the new products with the desired features. Degradation of the cross-linked structure and recycling of copolymers were also discussed.

Topological Polymer Networks with Sliding Cross-Link Points:  The “Sliding Gels”. Relationship between Their Molecular Structure and the Viscoelastic as Well as the Swelling Properties

2007 ◽  
Vol 40 (3) ◽  
pp. 535-543 ◽  
Author(s):  
Guillaume Fleury ◽  
Guy Schlatter ◽  
Cyril Brochon ◽  
Christophe Travelet ◽  
Alain Lapp ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Polymer Networks ◽  
Cross Link ◽  
Swelling Properties

Semi-interpenetrating Polymer Networks Containing Polysaccharides. I Xanthan/Lignin Networks

2007 ◽  
Vol 19 (5-6) ◽  
pp. 603-620 ◽  
Author(s):  
Irina Elena Raschip ◽  
Cornelia Vasile ◽  
Diana Ciolacu ◽  
Georgeta Cazacu
Keyword(s):  
Xanthan Gum ◽  
Polymer Network ◽  
Polymer Networks ◽  
Temperature Stability ◽  
Interpenetrating Polymer Networks ◽  
Interpenetrating Polymer Network ◽  
Helical Conformation ◽  
Swelling Properties ◽  
Food Ingredients ◽  
Swelling Rate

The polysaccharides are important materials in food, pharmaceutical, cosmetic and related biomedical applications. Xanthan gum is a microbial polysaccharide of great commercial significance. It is well known as one of the best thickening polymers due to its high intrinsic stiffness related to the helical conformation stabilized in the presence of excess salt. It is used in a wide variety of foods for a number of important reasons, including emulsion stabilization, temperature stability, compatibility with food ingredients, and its pseudoplastic rheological properties. Due to its properties in thickening aqueous solutions, as a dispersing agent, and stabilizer of emulsions and suspensions, xanthan gum is used in pharmaceutical formulations, cosmetics, and agricultural products, as well as in textile printing pastes, ceramic glazes, slurry explosive formulations, and rust removers. In this work the crosslinking of a mixture of xanthan and lignins in the presence of the epichlorohydrin, leading to superabsorbant hydrogels with high swelling rate in aqueous mediums, was studied. The swelling properties of these composite hydrogels were investigated. Three different types of lignin have been used namely: aspen wood lignin (L), annual fiber crop lignin (GL) and lignin epoxy-modified resin (LER). Semi-interpenetrating polymer network hydrogels in various ratios were prepared. The influence of gravimetric ratio between components of the semi-interpenetrating polymer networks, as well as the kinetics of water sorption will be discussed. The maximum swelling degree of the hydrogels and the swelling rate constant were determined as a function of the hydrogel's composition. It has been established that the nature of lignin significantly influences swelling process, the chemical modified lignin having a particular behavior.

scholarly journals Semi-interpenetrating polymer networks based on polyacrylamide and poly[itaconic acid]

2003 ◽  
Vol 57 (11) ◽  
pp. 543-546 ◽  
Author(s):  
Melina Kalagasidis-Krusic ◽  
Biljana Nikolic ◽  
Jovanka Filipovic
Keyword(s):  
Itaconic Acid ◽  
Polymer Network ◽  
Polymer Networks ◽  
Low Ph ◽  
Interpenetrating Polymer Networks ◽  
Polyacrylamide Gel ◽  
Swelling Properties ◽  
Swelling Degree ◽  
Equilibrium Swelling ◽  
Carboxylic Groups

The effect of pH and temperature on the equilibrium swelling properties of PIA/PAAm semi-IPNs were investigated.Semi-IPNs based on polyacrylamide (PAAm) and poly(itaconic acid) (PIA) were prepared by two different techniques, by polymerizing itaconic acid in the presence of polyacrylamide gel (Semi-IPNs-l) and by making the polyacrylamide gel in the presence of previously synthesized poly(itaconic acid) (Semi-IPNs-ll), with different PIA/PAAm mass ratios. The equilibrium swelling degree of an ionic network depends very much on the concentration of ionisable groups. The addition of a small amount of itaconic acid dramatically changes the swelling behavior of PAAm. Increase of the ionic monomer (IA) produces swelling degrees that increase to a high extent when the pH of the buffer solution is higher than the nominal pKa values of the acid groups. Gels with higher IA content swell less than PAAm gels in low pH buffers. At low pH, when complexation due to hydrogen bonding occurs between the carboxylic groups and amide groups of acrylamide, the polymer network collapses and the swelling ratio is low. The presence of hydrogen bonds in the complexes causes additional constraints in the network, acting as a physical crosslinking and makes the network less hydrophilic, because the carboxylic groups on the PIA are occupied in the complexes. As opposed to this, the equilibrium swelling degrees change very little with pH of the solution in nonionic PAAm gel.Hydrogels exhibit continuous changes in water content as a function of temperature. The swelling degree increases with increasing temperature due to gel expansion upon warming.

scholarly journals Investigation of Gel Properties of Novel Cryo-Clay-Silica Polymer Networks

Gels ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 11
Author(s):  
Patrik Berg ◽  
Carsten Dieter Prowald ◽  
Dirk Kuckling
Keyword(s):  
Tensile Strength ◽  
Silica Gel ◽  
Polymer Networks ◽  
Gel Strength ◽  
Gel Properties ◽  
Swelling Properties ◽  
Degree Of Swelling ◽  
Swelling Kinetic ◽  
Responsive Behavior ◽  
Post Modification

Several methods to increase the mechanical and swelling properties of Poly(N-isopropylacrylamide) gels are known. In this study different methods were combined to systematically alter the gel properties. The combination of nanocomposite and cryo gels as well as silica post modification was used to modulate the gel strength. This new cryo-clay-silica gel based on N-isopropylacrylamide was investigated in respect to degree of swelling, kinetic of thermo responsive behavior and tensile strength. Here, the properties of new cryo-clay-silica gel were compared with properties of clay-, silica-clay and cryo-clay gels.

scholarly journals Optimization of swelling response of pH sensitive hydrogels using Box-Behnken design

2018 ◽  
Author(s):  
Fereshteh Shokri ◽  
Pouneh Ebrahimi ◽  
Soheyla Honary
Keyword(s):  
Polymer Networks ◽  
Three Dimensional ◽  
Statistical Design ◽  
Ph Sensitive ◽  
Vinyl Pyrrolidone ◽  
Swelling Properties ◽  
Screening Design ◽  
Statistical Screening ◽  
Poly Vinyl Pyrrolidone ◽  
Responsive Hydrogels

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.

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