scholarly journals Multi-Responsive Polysiloxane/Poly(N-isopropylacrylamide) Interpenetrating Networks Containing Urea and Thiourea Groups

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1175 ◽  
Author(s):  
Junta Sano ◽  
Shigeki Habaue
Keyword(s):  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Interpenetrating Networks ◽  
Volume Changes ◽  
Fluoride Ions ◽  
Temperature Responsive ◽  
Chemical Stimuli ◽  
Nipam Gel ◽  
Typical Temperature ◽  
Polysiloxane Gel

Novel interpenetrating polymer networks (IPNs) were synthesized from N-isopropylacrylamide (NIPAM) and polysiloxanes containing a urea or thiourea side group, in addition to the silanol residue, through two reactions, such as the radical gelation of NIPAM and the condensation of silanols to form a siloxane linkage. The obtained IPNs showed a typical temperature-responsive volume change in water based on the constructed poly-NIPAM gel component. In addition, the characteristic color and volume changes responding to chemical stimuli, such as acetate and/or fluoride ions, based on the introduced urea and thiourea groups onto the polysiloxane gel were observed in N,N-dimethylformamide.

Continuous Fabrication of Temperature-Responsive Hydrogel Fibers with Bilayer Structure by Microfluidic Spinning

2019 ◽  
Vol 944 ◽  
pp. 543-548 ◽  
Author(s):  
Mei Ling Zhou ◽  
Dan Mei Hu ◽  
Yu Jie Shao ◽  
Jing Hong Ma ◽  
Jing Hua Gong
Keyword(s):  
Stress Measurement ◽  
Layer Structure ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Ratio Test ◽  
Bilayer Structure ◽  
Temperature Responsive ◽  
Ionic Crosslinking ◽  
Equilibrium Swelling Ratio ◽  
Continuous Fabrication

Temperature-responsive hydrogel fibers with bilayer structure were prepared by a microfluidic spinning device with a Y-shaped connector. The bilayer hydrogel fibers include two layer with different chemical composition. One layer is the ionic crosslinking hydrogel of calcium alginate (CA) and the other layer is temperature-responsive hydrogel which is semi-interpenetrating polymer networks (semi-IPN) of linear poly (N-isopropylacrylamide) (PNIPAM) and CA. The bilayer hydrogel fibers were evaluated by morphology observation, tensile stress measurement, temperature-responsive actuation test and equilibrium swelling ratio test. The results show that the prepared hydrogel fibers have obvious double layer structure with different porous structures. The bilayer hydrogel fibers can bend in water at 50 °C and the bending rate is influenced by the diameter of the fiber. Moreover, the diameter of the hydrogel fibers can be controlled by changing the flow rates of spinning fluids.

Modelling Stress Softening and Necking Phenomena in Double Network Hydrogels

2019 ◽  
Author(s):  
Vahid Morovati ◽  
Mohammad Ali Saadat ◽  
Roozbeh Dargazany
Keyword(s):  
Polymer Networks ◽  
Three Dimensional ◽  
Interpenetrating Polymer Networks ◽  
Biological Applications ◽  
Inelastic Behavior ◽  
Interpenetrating Networks ◽  
Double Network ◽  
Stress Softening ◽  
Proposed Model ◽  
Damage Process

Abstract Double network (DN) gels are three-dimensional polymer matrices formed by interpenetrating networks. In contrast to the conventional single-network gels, DN gels have significant toughness, which makes them a promising material for different biomedical and biological applications. However, DN gels show complicated inelastic behavior including the Mullins effect and necking instability. Despite extensive efforts on modelling different aspects of the damage process in gels, the micro-mechanical modelling of the mechanisms that lead to necking in DN gels remains to be a challenging task. Here, a constitutive model is proposed to understand and describe the mechanical behavior of DN gels based on statistical micro-mechanics of interpenetrating polymer networks. DN gels behavior is divided into three parts including pre-necking, necking, and hardening. The first network is dominant in the response of the gel in the pre-necking stage. The breakage of the first network to smaller network fractions (clusters) induces the stress softening observed in this stage. The interaction of both networks and the second network are also considered as main contributors to the response of gel in necking and hardening stages, respectively. The contribution of clusters decreases during the necking as the second network starts hardening. The numerical results of the proposed model are validated and compared by uni-axial cyclic tensile experimental data of DN gels.

Semi-Interpenetrating Networks of Sulfur-Containing Bismaleimides

1993 ◽  
Vol 5 (4) ◽  
pp. 297-305 ◽  
Author(s):  
F P Glatz ◽  
R Mdiilhaupt
Keyword(s):  
Mechanical Properties ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Acid Anhydride ◽  
Resin System ◽  
Tetracarboxylic Acid ◽  
Interpenetrating Networks ◽  
Sulfur Containing ◽  
Phenylene Sulfide

Microphase-separated semi-interpenetrating polymer networks (semi-n Ns) were obtained by curing 4,4'-bismaleimidodiphenylmethane (BMII), which was advanced in situ with diamine-terminated oligo(phenylene sulfide) (PPS-DA), in the presence of a non-crosslinked linear high-T, aromatic polyether. Poly(thioether amide imide) (PTEAI) containing two phenylene sulfide units, Ultems 1000 poly(ether imide) (PEI) and benzophenone tetracarboxylic acid anhydride/diaminophenylindane polyimnide XU 218$ (PI) were used as non-crosslinked modifiers for the sulfur-containing BMI/PPS-DA resin system, which formed the continuous polymer matrix. Morphological and mechanical properties of the polyether-modified BMI/PPS-DA resin systems were investigated as a function of semi-n?,-compositions and polymer compatibilities. The soluble high-TA P1 gave improved strength and toughness without sacrificing the high T, of the resulting multiphase semi-iPNS.

In situ calcium phosphate deposition in hydrogels of poly(acrylic acid)–polyacrylamide interpenetrating polymer networks

RSC Advances ◽  
2016 ◽  
Vol 6 (20) ◽  
pp. 16274-16284 ◽  
Author(s):  
M. S. Simeonov ◽  
A. A. Apostolov ◽  
E. D. Vassileva
Keyword(s):  
Calcium Phosphate ◽  
Acrylic Acid ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Interpenetrating Networks ◽  
Naturally Occurring ◽  
First Time ◽  
Poly Acrylic Acid

Interpenetrating networks of poly(acrylic acid) and polyacrylamide were used for the first time as templates for in situ calcium phosphate (CP) deposition in an attempt to mimic the naturally occurring biomineralization.

Temperature-Responsive Interpenetrating Polymer Networks Constructed with Poly(acrylic acid) and Poly(N,N-dimethylacrylamide)

1994 ◽  
Vol 27 (4) ◽  
pp. 947-952 ◽  
Author(s):  
Takashi Aoki ◽  
Masahiko Kawashima ◽  
Hiroki Katono ◽  
Kohei Sanui ◽  
Naoya Ogata ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Temperature Responsive ◽  
Poly Acrylic Acid

Ionic semi-interpenetrating networks as a new approach for highly conductive and stretchable polymer materials

2015 ◽  
Vol 3 (5) ◽  
pp. 2188-2198 ◽  
Author(s):  
Alexander S. Shaplov ◽  
Denis O. Ponkratov ◽  
Petr S. Vlasov ◽  
Elena I. Lozinskaya ◽  
Lyudmila V. Gumileva ◽  
...  
Keyword(s):  
Polymer Films ◽  
Polymer Networks ◽  
Conductive Polymer ◽  
Interpenetrating Polymer Networks ◽  
Polymer Materials ◽  
Synthesis And Characterization ◽  
Interpenetrating Networks ◽  
New Approach

The synthesis and characterization of ionically conductive polymer films with high stretchability and good elasticity based on ionic semi-interpenetrating polymer networks (semi-IPNs) are discussed.

scholarly journals Semi-interpenetrating networks based on POLY(N-isopropyl acrilamide) and POLY(N-vinylpyrrolidone)

2007 ◽  
Vol 61 (6) ◽  
pp. 350-356 ◽  
Author(s):  
Dragana Zugic ◽  
Pavle Spasojevic ◽  
Jasna Djonlagic
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Molar Ratio ◽  
Dynamic Shear Modulus ◽  
Interpenetrating Networks ◽  
Elongation At Break ◽  
Equilibrium Degree ◽  
Degree Of Swelling

Three series of semi-interpenetrating polymer networks based on cross-linked poly(N-isopropylacrylamide), PNIPA, and 1, 2 and 3 wt% of linear poly(N-vinylpyrrolidone), PVP, were synthesized in order to improve the mechanical properties of PNIPA gels. The effect of the incorporation of the linear PVP polymer into the temperature responsive networks on the phase transition temperature, swelling behavior and mechanical properties was studied. Polymer networks with four different crosslinking densities were prepared with various molar ratios (25/1 to 100/1) of the monomer (N-isopropylacrylamide) to the cross linker (N,N'-methylene-bisacrylamide). The hydrogels were characterized by determination of the equilibrium degree of swelling at 25 ?C, the dynamic shear modulus and the effective crosslinking density, as well as the ultimate hydrogel properties, such as the tensile strength and elongation at break. Furthermore, the deswelling kinetics of the hydrogels was also studied by measuring their water retention capacity. The inclusion of the linear hydrophilic PVP in the PNIPA networks increased the equilibrium degree of swelling, the highest values of which were obtained for samples with 2 and 3 wt% of PVP and the NIPA/MBA molar ratio of 75/1 and 100/1. The highest reinforcement effect, evaluated from the ratio of G'red(semi-IPN) to G'red(PNIPA), was obtained by incorporation of 2 wt% PVP. The tensile strength of the semi-IPNs reinforced with linear PVP was higher than that of the PNIPA networks. The elongation at break of these semi-IPNs varied between 22 and 55%, which are 22^11% larger than those for single PNIPA networks. The tensile measurements confirmed that the presence of 2 wt% of the linear polymer significantly reinforced the PNIPA network.

scholarly journals The microscopic distribution of hydrophilic polymers in interpenetrating polymer networks (IPNs) of medical grade silicone

Polymer ◽  
2021 ◽  
Vol 224 ◽  
pp. 123671
Author(s):  
Gregory N. Smith ◽  
Erik Brok ◽  
Martin Schmiele ◽  
Kell Mortensen ◽  
Wim G. Bouwman ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Hydrophilic Polymers ◽  
Microscopic Distribution ◽  
Medical Grade
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