Novel Cross-Linking Concept of Polymer Network: Synthesis, Structure, and Properties of Slide-Ring Gels with Freely Movable Junctions

Thermoset polymers are an area of intense research due to their low cost, ease of processing, environmental resistance, and unique physical properties. The favorable properties of this class of polymers have many applications in aerospace, automotive, marine, and sports equipment industries. Molecular simulations of thermosets are frequently used to model formation of the polymer network, and to predict the thermomechanical properties. These simulations usually require custom algorithms that are not easily accessible to non-experts and not suited for high throughput screening. To address these issues, we have developed a robust cross-linking algorithm that can incorporate different types of chemistries and leverage GPU-enabled molecular dynamics simulations. Automated simulation analysis tools for cross-linking simulations are also presented. Using four well known epoxy/amine formulations as a foundational case study and benzoxazine as an example of how additional chemistries can be modeled, we demonstrate the power of the algorithm to accurately predict curing and thermophysical properties. These tools are able to streamline the thermoset simulation process, opening up avenues to in-silico high throughput screening for advanced material development.

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Hydrogel-Silver Nanoparticle Composites for Biomedical Applications

Ukrainian Journal of Physics ◽

10.15407/ujpe65.5.446 ◽

2020 ◽

Vol 65 (5) ◽

pp. 446

Author(s):

O. Nadtoka ◽

N. Kutsevol ◽

T. Bezugla ◽

P. Virych ◽

A. Naumenko

Keyword(s):

Silver Nanoparticle ◽

Biomedical Applications ◽

Polymer Network ◽

Cross Linking ◽

Polyacrylamide Hydrogels ◽

Photochemical Generation ◽

Vis Spectroscopy ◽

Swelling Capacity ◽

Swelling Studies ◽

Nanoparticle Composites

Polyacrylamide and dextran-graft-polyacrylamide hydrogels are prepared and used as nanoreactors and networks for the synthesis of silver nanoparticles (AgNPs). Photochemical generation of AgNPs is carried out under UV-irradiation of Ag+ ions in swollen hydrogels of different cross-linking densities. The obtained hydrogels and hydrogel/AgNPs composites are characterized by TEM, FTIR, and UV–Vis spectroscopy. Swelling studies have shown a relationship between the structure of the hydrogels and their ability to swell. It is shown that the presence of AgNPs in the polymer network leads to a decrease of the swelling capacity. An increase in the cross-linking density leads to an expansion of the AgNPs size distribution for both types of hydrogels. All synthesized hydrogel-silver nanoparticle composites have shown a high activity in the growth retardation of Staphylococcus aureus microorganisms.

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Synthesis and characterization of a novel wound dressing by PVP/ PAANa/chitosan with semi-interpenetrating polymer network structure

e-Polymers ◽

10.1515/epoly.2012.12.1.674 ◽

2012 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Ying Wu ◽

Qing Yang ◽

Yali Gi ◽

Yueting Zhang

Keyword(s):

Network Structure ◽

Wound Dressing ◽

Polymer Network ◽

Interpenetrating Polymer Network ◽

Wound Dressings ◽

Synthesis And Characterization ◽

Cross Linking ◽

Mass Ratio ◽

Scanning Electron

AbstractA novel hydrogel wound dressing with semi-interpenetrating polymer network structure (semi-IPN) was prepared by radical polymerization of acrylic acid with potassium persulfate (K2S2O8) as initiator and N, N'-methylenebisacrylamide (MBA) as cross-linking agent in the presence of chitosan (CTS) and polyvinyl pyrrolidone (PVP). Hydrogels were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). SEM displayed semi- IPN hydrogels' creased surface with some scale-like wrinkles, thus improving the absorptive capability which has been considered as a most important characteristic of wound dressings. It was found that the content of cross-linking agent and the mass ratio of PVP and CTS had much influence on the mechanical properties of the hydrogel, varying from brittle plastics to elastomer due to the different degrees of cross linking. Since tensile strength is partly in inverse ratio to the hydrogel absorbent capability, the article offers an analysis of varying material proportion in order to obtain an optimum properties of the hydrogel wound dressing .

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Novel Ni/pHEMA-gr-PVP Composites Obtained by Polymerization with Simultaneous Metal Deposition: Structure and Properties

Materials ◽

10.3390/ma12121956 ◽

2019 ◽

Vol 12 (12) ◽

pp. 1956 ◽

Cited By ~ 6

Author(s):

Oleksandr Grytsenko ◽

Ivan Gajdoš ◽

Emil Spišák ◽

Volodymyr Krasinskyi ◽

Oleh Suberlyak

Keyword(s):

Chemical Reduction ◽

Structural Parameters ◽

Polymer Network ◽

Exothermic Reaction ◽

Infrared Analysis ◽

Structure And Properties ◽

Electrical And Magnetic Properties ◽

Metal Filler ◽

Nickel Particles ◽

Heat Released

The synthesis and study of metal-containing hydrogels, particularly those filled with nickel nanoparticles, is currently of interest to many researchers. This paper presents the results of an investigation of the structure and properties of Ni(0)-filled composites on the basis of 2-hydroxyethylmethacrylate copolymers (HEMA) with polyvinylpyrrolidone (PVP) and their hydrogels. The authors of the article are the first who propose the method to produce these materials by combining the processes of polymer matrix synthesis and a reduction of Ni2+ ions. Synthesis is carried out in one stage without complicated equipment and is technologically simple. It is determined by thermometric research that the temperature conditions required for the chemical reduction of Ni2+ are achieved due to the heat released during the exothermic reaction of HEMA polymerization in the presence of PVP. With the help of Fourier transform infrared analysis, and thermogravimetric and differential-thermal analysis, the formation of a crosslinked graft copolymer based on HEMA and PVP was confirmed, and its structural parameters, including the efficiency of PVP grafting, PVP content in the copolymer, and the molecular weight of the interstitial fragment of the polymer network, were investigated. The results obtained with scanning electron microscopy revealed that the size of the Ni(0) particles is about 500 nm. X-ray structural analysis of the composites obtained confirmed the existence of metal nickel particles. The strength, elastic, sorption, electrical, and magnetic properties of the obtained composites in the solid (dry) and elastic (swollen) physical states, depending on the composition of the copolymer and the content of the metal filler, have been investigated.

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Observation of Glass Transition Temperatures in Polymeric Thin Films by Wafer Curvature Measurements

MRS Proceedings ◽

10.1557/proc-239-37 ◽

1991 ◽

Vol 239 ◽

Cited By ~ 1

Author(s):

P. H. Townsend ◽

B. S. Huber ◽

D. S. Wang

Keyword(s):

Thin Films ◽

Glass Transition ◽

Transition Temperature ◽

Polymer Network ◽

Cross Linking ◽

Positional Isomers ◽

Glass Transition Temperatures ◽

Thin Coatings ◽

Polymeric Thin Films ◽

Curvature Measurements

ABSTRACTWafer bending measurements have been used to study the glass transition temperature, Tg, of thin coatings of polystyrene and polycarbonate on Si wafers. The observed values of Tg agree with DSC and TMA measurements on bulk samples. The evolution of the substrate curvature has been used to examine the behavior of Tg in thin epoxy films and coatings derived from divinylsiloxane bisbenzocyclobutene, mixed stereo and positional isomers of 1, 3-bis(2-bicyclo[4.2.0]octa-1, 3, 5-trien-3-ylethenyl)-1, 1, 3, 3-tetramethyl disitoxane (CAS 117732–87–3). The dependence of the Tg of the epoxide coatings is studied as a function of the cross-linking. The evolution of the Tg in the benzocyclobutene coating is found to be a monotonie function of the level of conversion of the polymer network.

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Structure and properties of polystyrene-polyethylene interpenetrating polymer network (ipn)-like systems

Macromolecular Symposia ◽

10.1002/masy.19940830113 ◽

1994 ◽

Vol 83 (1) ◽

pp. 147-156 ◽

Cited By ~ 7

Author(s):

Eberhard Borsig ◽

Agnesa Fiedlerová ◽

Karl G. Häusler ◽

Goerg H. Michler ◽

Roberto Greco

Keyword(s):

Polymer Network ◽

Interpenetrating Polymer Network ◽

Structure And Properties

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Studies of Formation Mechanism, Structure, and Properties of Network Copolymers Obtained by Cocuring of Rolivsan Thermosetting Resins with Aromatic Diamines

International Journal of Polymer Science ◽

10.1155/2019/1601236 ◽

2019 ◽

Vol 2019 ◽

pp. 1-15

Author(s):

B. A. Zaitsev ◽

L. G. Kleptsova ◽

I. D. Shvabskaya

Keyword(s):

Glass Transition ◽

High Temperature ◽

Thermal Analyses ◽

Polymer Network ◽

Three Dimensional ◽

Transition Temperatures ◽

Structure And Properties ◽

Aromatic Diamines ◽

Thermosetting Resins ◽

Glass Transition Temperatures

Rolivsan thermosetting resins (ROLs) demonstrate high glass-transition temperatures and excellent processability. In our work, high-temperature properties of ROLs were significantly improved using a novel technique for structural and chemical modification of microheterogeneous network polymers. This technique involves, among other procedures, cocuring of rolivsan resins with aromatic diamines (ADA). The most noticeable increase in storage moduli and glass transition temperatures (Tg) of these copolymers was achieved when ROLs were modified with 10-15 wt.% of ADA and the resulting blends were subjected to thermal treatment in air in the temperature range 180 to 320°C for several hours. FTIR, 13С NMR spectroscopy, and dynamic mechanical and thermal analyses were used for studying the structure and properties of the obtained products. It was demonstrated that the mechanism of formation of ROL-ADA copolymers includes the following high-temperature reactions: (i) three-dimensional radical copolymerization of unsaturated ROL components and (ii) cleavage of heat-sensitive methacrylate crosslinking units inside the polymer network. The second process is accompanied by formation of pending units of methacrylic acid and methacrylic anhydride, which participate in condensation reactions with ADA.

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