scholarly journals Equilibrium swelling properties of polyampholytic hydrogels

1996 ◽  
Vol 104 (21) ◽  
pp. 8713-8720 ◽  
Author(s):  
Anthony E. English ◽  
Salvador Mafé ◽  
José A. Manzanares ◽  
Xiahong Yu ◽  
Alexander Yu. Grosberg ◽  
...  
Keyword(s):  
Swelling Properties ◽  
Equilibrium Swelling

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.

Investigation of NBR-cellulose II nanocomposites by rheometric and equilibrium swelling properties

2007 ◽  
Vol 60 (2-3) ◽  
pp. 281-290 ◽  
Author(s):  
Vera Lúcia da C. Lapa ◽  
Patrícia D. de Oliveira ◽  
Leila Léa Y. Visconte ◽  
Regina Celia R. Nunes
Keyword(s):  
Cellulose Ii ◽  
Swelling Properties ◽  
Equilibrium Swelling

scholarly journals Rheological and mechanical properties of wood flour filled polyisoprene/chlorosulphonated polyethylene rubber blends

2007 ◽  
Vol 13 (4) ◽  
pp. 186-191 ◽  
Author(s):  
Gordana Markovic ◽  
Milena Marinovic-Cincovic ◽  
Blaga Radovanovic ◽  
Jaroslava Budinski-Simendic
Keyword(s):  
Mechanical Properties ◽  
Phenol Formaldehyde ◽  
Wood Flour ◽  
Filler Loading ◽  
Swelling Properties ◽  
Rubber Blends ◽  
Equilibrium Swelling ◽  
Swelling Characteristics ◽  
Chlorosulphonated Polyethylene ◽  
Elastomeric Composites

The effect of wood flour (WF) on curing behavior and swelling properties of polyisoprene rubber/chlorosulphonated polyethylene (NR/CSM) rubber blends was investigated. The mechanical properties, as well as the equilibrium swelling characteristics of the elastomeric composites filled with WF (particle size from 300 to 400 ?m) were measured as a function of filler loading (the range of 0 to 50 phr) and compared with the values for the elastomeres based on commercial grade carbon black filler (nano-sized particles, 26-30 nm). In some formulations phenol-formaldehyde (PF) resins are used to achieve better adhesion between rubber macromolecules and filler particles. For WF filled elastomeres the maximum tensile strength of 11 MPa at 20 phr was recorded. Hardness of samples filled with WF increased with filler loading. Abrasion resistance decreases marginally with increasing filler loading. The equilibrium sorption in toluene of NR/CSM vulcanizates filled decreased with increasing filler loading for both type of filler.

scholarly journals Equilibrium Swelling of Biocompatible Thermo-Responsive Copolymer Gels

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 40
Author(s):  
Aleksey D. Drozdov
Keyword(s):  
Biomedical Applications ◽  
Hydrophobic Interactions ◽  
Volume Phase Transition ◽  
Biotechnological Applications ◽  
Vinyl Methyl ◽  
Potential Toxicity ◽  
Swelling Properties ◽  
Vinyl Methyl Ether ◽  
Equilibrium Swelling ◽  
Copolymer Gels

Biomedical applications of thermo-responsive (TR) hydrogels require these materials to be biocompatible, non-cytotoxic, and non-immunogenic. Due to serious concerns regarding potential toxicity of poly(N-isopropylacrylamide) (PNIPAm), design of alternative homo- and copolymer gels with controllable swelling properties has recently become a hot topic. This study focuses on equilibrium swelling of five potential candidates to replace PNIPAm in biomedical and biotechnological applications: poly(N-vinylcaprolactam), poly(vinyl methyl ether), poly(N,N-dimethyl amino ethyl methacrylate), and two families of poly(2-oxazoline)s, and poly(oligo(ethylene glycol) methacrylates). To evaluate their water uptake properties and to compare them with those of substituted acrylamide gels, a unified model is developed for equilibrium swelling of TR copolymer gels with various types of swelling diagrams. Depending on the strength of hydrophobic interactions (high, intermediate, and low), the (co)polymers under consideration are split into three groups that reveal different responses at and above the volume phase transition temperature.

Carbon Black-Loaded GR-S Stocks. Relationship between Reinforcement and Swelling Properties

1949 ◽  
Vol 22 (3) ◽  
pp. 805-811
Author(s):  
E. M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Strong Interaction ◽  
Swelling Properties ◽  
Reinforcing Effect ◽  
Low Concentrations ◽  
Equilibrium Swelling ◽  
Physical Mixtures ◽  
Primary Valence

Abstract The fact that equilibrium swelling measurements do not show any strong interaction of a primary-valence type between filler and rubber does not exclude the possibility of weaker attractive forces, or such low concentrations of primary valence cross-linkages that they cannot be detected by the methods used. The results of this work indicate that carbon black—rubber systems should be considered as simple physical mixtures. It is hoped that this concept will clarify some of the confusion regarding the reinforcing effect of finely divided powders.

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