scholarly journals Selection of structural elements of cross-linked polymers used in construction

Vestnik MGSU ◽  
2021 ◽  
pp. 347-359
Author(s):  
Andrey A. Askadskii ◽  
Sergey V. Matseevich ◽  
Tat’yana A. Matseevich
Keyword(s):  
Thermal Conductivity ◽  
Glass Transition ◽  
Computer Program ◽  
Water Permeability ◽  
Polymer Network ◽  
Polymer Networks ◽  
Physical Characteristics ◽  
Network Polymers ◽  
Optical Coefficient ◽  
Selection Of

Introduction. For the first time, a model and a principle for constructing an appropriate computer program for the selection of polymer networks with a given interval of a number of physical characteristics are proposed. These characteristics include density, the temperature of the onset of intense thermal degradation, thermal conductivity, water permeability, and the stress-optical coefficient. As an example, 16 smallest base fragments are given, which, when attached to each other, allow the selection of structural fragments of repeating fragments of polymers of the following classes: polyolefins, vinyl polymers, polystyrene, polyamides, polyethers and polyesters, polycarbonates, polyetherketones, polyimides, polysulfides, polysulfones, silicone polymers, polyurethanes, cellulose derivatives, methacrylic polymers, etc. The purpose of the study is to develop a model for writing a computer program that allows the selection of structural fragments of network polymers possessing specified intervals of physical characteristics. For polymers used in the construction industry, the most important are the glass transition temperature, the stress-optical coefficient, density, water permeability, and thermal conductivity. Materials and methods. A repeating fragment of the network is selected from the smallest basic fragments, which are connected to each other using a control matrix of interactions. The matrix contains labels that allow you to control the interaction of carbon with three carbon atoms, with a carbon atom and two nitrogen atoms, with two carbon atoms and one oxygen atom, with two carbon atoms and one nitrogen atom, with four carbon atoms. There are also labels that control the interaction of carbon atoms included in the aromatic cycles with two carbon atoms and one oxygen atom, with four carbon atoms, with four nitrogen atoms, with two carbon atoms and one sulfur atom, and three oxygen atoms. This makes it possible to select a huge amount of cross-linked polymer. Results. As an example, the possible chemical structure of 14 cross-linked nodes of the polymer network is presented and the corresponding calculations are carried out, showing the adequacy of the model and the principle of constructing a computer program. The structures of the five cross-linked nodes of polymer network were used and the following physical characteristics of the resulting networks were calculated: density, the temperature of the onset of intense thermal degradation, water permeability, thermal conductivity, and the stress-optical coefficient. All these characteristics are important for the manufacture of building materials. Conclusions. The results of the work allow us to write a real computer program for the selection of repeating fragments of polymer networks that have a given interval of a number of important physical characteristics of network polymers. Among these characteristics are not only those listed above, but also other characteristics, such as glass transition temperature, Hildebrand solubility parameter, surface energy, heat capacity, intermolecular interaction energy, permittivity, etc.

Ability to Control the Glass Transition Temperature of Amorphous Shape-Memory Polyesterurethane Networks by Varying Prepolymers in Molecular Mass as well as in Type and Content of Incorporated Comonomers

2009 ◽  
Vol 1190 ◽  
Author(s):  
Joerg Zotzmann ◽  
Steffen Kelch ◽  
Armin Alteheld ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Glass Transition ◽  
Minimally Invasive Surgery ◽  
Shape Memory ◽  
Molecular Mass ◽  
Amorphous Polymer ◽  
Polymer Networks ◽  
Precise Control ◽  
Low Weight ◽  
Switching Temperature ◽  
Selection Of

AbstractThe need of intelligent implant materials for applications in the area of minimally invasive surgery leads to tremendous attention for polymers which combine degradability and shape-memory capability. Application of heat, and thereby exceeding a certain switching temperature Tsw, causes the device to changes its shape. The precise control of Tsw is particularly challenging. It was investigated in how far Tg, that can be used as Tsw, of amorphous polymer networks from star-shaped polyester macrotetrols crosslinked with a low-weight linker can be controlled systematically by incorporation of different comonomers into poly(rac-lactide) prepolymers. The molecular mass of the prepolymers as well as type and content of the comonomers was varied. The Tg could be adjusted by selection of comonomer type and ratio without affecting the advantageous elastic properties of the polymer networks.

scholarly journals Influence of Material Properties on the Damage-Reporting and Self-Healing Performance of a Mechanically Active Dynamic Network Polymer in Coating Applications

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2468
Author(s):  
Da Hae Son ◽  
Gi Young Kim ◽  
Ji-Eun Jeong ◽  
Sang-Ho Lee ◽  
Young Il Park ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Material Properties ◽  
Substrate Surface ◽  
Polymer Network ◽  
Polymer Networks ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Self Healing

We conducted a detailed investigation of the influence of the material properties of dynamic polymer network coatings on their self-healing and damage-reporting performance. A series of reversible polyacrylate urethane networks containing the damage-reporting diarylbibenzofuranone unit were synthesized, and their material properties (e.g., indentation modulus, hardness modulus, and glass-transition temperature) were measured conducting nanoindentation and differential scanning calorimetry experiments. The damage-reporting and self-healing performances of the dynamic polymer network coatings exhibited opposite tendencies with respect to the material properties of the polymer network coatings. Soft polymer network coatings with low glass-transition temperature (~10 °C) and indentation hardness (20 MPa) exhibited better self-healing performance (almost 100%) but two times worse damage-reporting properties than hard polymer network coatings with high glass-transition temperature (35~50 °C) and indentation hardness (150~200 MPa). These features of the dynamic polymer network coatings are unique; they are not observed in elastomers, films, and hydrogels, whereby the polymer networks are bound to the substrate surface. Evidence indicates that controlling the polymer’s physical properties is a key factor in designing high-performance self-healing and damage-reporting polymer coatings based on mechanophores.

A Novel Poly(Ionic Liquid) as the Thermal Insulating Material

2020 ◽  
Vol 13 (3) ◽  
pp. 241-247
Author(s):  
Wenxin Wei ◽  
Guifeng Ma ◽  
Hongtao Wang ◽  
Jun Li
Keyword(s):  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flame Resistance ◽  
Insulating Material ◽  
Low Thermal Conductivity ◽  
Thermal Insulating ◽  
Poly Ionic Liquid

Objective: A new poly(ionic liquid)(PIL), poly(p-vinylbenzyltriphenylphosphine hexafluorophosphate) (P[VBTPP][PF6]), was synthesized by quaternization, anion exchange reaction, and free radical polymerization. Then a series of the PIL were synthesized at different conditions. Methods: The specific heat capacity, glass-transition temperature and melting temperature of the synthesized PILs were measured by differential scanning calorimeter. The thermal conductivities of the PILs were measured by the laser flash analysis method. Results: Results showed that, under optimized synthesis conditions, P[VBTPP][PF6] as the thermal insulator had a high glass-transition temperature of 210.1°C, high melting point of 421.6°C, and a low thermal conductivity of 0.0920 W m-1 K-1 at 40.0°C (it was 0.105 W m-1 K-1 even at 180.0°C). The foamed sample exhibited much low thermal conductivity λ=0.0340 W m-1 K-1 at room temperature, which was comparable to a commercial polyurethane thermal insulating material although the latter had a much lower density. Conclusion: In addition, mixing the P[VBTPP][PF6] sample into polypropylene could obviously increase the Oxygen Index, revealing its efficient flame resistance. Therefore, P[VBTPP][PF6] is a potential thermal insulating material.

scholarly journals Bisphenol-Free Epoxy Resins Derived from Natural Resources Exhibiting High Thermal Conductivity

Proceedings ◽  
2020 ◽  
Vol 69 (1) ◽  
pp. 18
Author(s):  
Matthias Sebastian Windberger ◽  
Evgenia Dimitriou ◽  
Frank Wiesbrock
Keyword(s):  
Thermal Conductivity ◽  
Natural Resources ◽  
Polymer Networks ◽  
Sio2 Nanoparticles ◽  
Diglycidyl Ether ◽  
Epoxy Compound ◽  
Inorganic Materials ◽  
Limiting Factor ◽  
Epoxy Amine ◽  
Π Stacking

Polymers commonly have low thermal conductivity in the range of 0.1–0.2 W·m−1·K−1, which is a limiting factor for their usage in the course of continuously increasing miniaturization and heat generation in electronic applications. Two strategies can be applied to increase the transport of phonons in polymers: (i) the embedment of thermally conductive inorganic materials and (ii) the involvement of aromatic units enabling anisotropy by π–π stacking. In this study, the thermal conductivity of resins based on bisphenol A diglycidyl ether BADGE and 1,2,7,8-diepoxyoctane DEO was compared. DEO can be derived from pseudo-pelletierine, which is contained in the bark of the pomegranate tree. The epoxy compounds were cured with isophorone diamine IPDA, o-dianisidine DAN, or mixtures of the both diamines. Notably, isophorone diamine is derived from isophorone of which the latter naturally occurs in cranberries. The formulations were produced without filler or with 5 wt.-% of SiO2 nanoparticles. Significantly enhanced thermal conductivity in the range of 0.4 W·m−1·K−1 occurs only in DEO-based polymer networks that were cured with DAN (and do not contain SiO2 fillers). This observation is argued to originate from π–π stacking of the aromatic units of DAN enabled by the higher flexibility of the aliphatic carbon chain of DEO compared to that of BADGE. This assumption is further supported by the facts that significantly improved thermal conductivity occurs only above the glass-transition temperature and that nanoparticles appear to disrupt the π–π stacking of the aromatic groups. In summary, it can be argued that the bisphenol-free epoxy/amine resin with an epoxy compound derivable from natural resources shows favorably higher thermal conductivity in comparison to the petrol-based epoxy/amine resins.

A New Derivation of Postgel Properties of Network Polymers

1976 ◽  
Vol 49 (5) ◽  
pp. 1219-1231 ◽  
Author(s):  
D. R. Miller ◽  
C. W. Macosko
Keyword(s):  
General Result ◽  
Crosslink Density ◽  
Polymer Network ◽  
Probability Generating Function ◽  
Finite Chain ◽  
Network Polymer ◽  
Network Polymers ◽  
Property Relations ◽  
Recursive Scheme ◽  
Effective Network

Abstract The probability of a finite or dangling chain on an ideal polymer network has been derived by a simple recursive scheme. In contrast to the method of Dobson and Gordon, probability generating function formalism is not required. The general result, Equations (21), and its specific solutions, Equations (23), (24), and (30), give the finite chain probability as a function of reactant type and extent of polymerization. They cover most of the important types of network forming polymerizations. From the finite chain probability, useful property relations such as sol fraction, crosslink density, and the number of elastically effective network chains are developed. Because of their simplicity, we expect these relations to be further developed and applied to network polymer property measurements.

Silk Polymer Coating with Low Dielectric Constant and High Thermal Stability for Ulsi Interlayer Dielectric

1997 ◽  
Vol 476 ◽  
Author(s):  
P. H. Townsend ◽  
S. J. Martin ◽  
J. Godschalx ◽  
D. R. Romer ◽  
D. W. Smith ◽  
...  
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Integrated Circuits ◽  
Room Temperature ◽  
Polymer Network ◽  
Flow Characteristics ◽  
Interlayer Dielectric

AbstractA novel polymer has been developed for use as a thin film dielectric in the interconnect structure of high density integrated circuits. The coating is applied to the substrate as an oligomeric solution, SiLK*, using conventional spin coating equipment and produces highly uniform films after curing at 400 °C to 450 °C. The oligomeric solution, with a viscosity of ca. 30 cPs, is readily handled on standard thin film coating equipment. Polymerization does not require a catalyst. There is no water evolved during the polymerization. The resulting polymer network is an aromatic hydrocarbon with an isotropie structure and contains no fluorine.The properties of the cured films are designed to permit integration with current ILD processes. In particular, the rate of weight-loss during isothermal exposures at 450 °C is ca. 0.7 wt.%/hour. The dielectric constant of cured SiLK has been measured at 2.65. The refractive index in both the in-plane and out-of-plane directions is 1.63. The flow characteristics of SiLK lead to broad topographic planarization and permit the filling of gaps at least as narrow as 0.1 μm. The glass transition temperature for the fully cured film is greater than 490 °C. The coefficient of thermal expansivity is 66 ppm/°C below the glass transition temperature. The stress in fully cured films on Si wafers is ca. 60 MPa at room temperature. The fracture toughness measured on thin films is 0.62 MPa m ½. Thin coatings absorb less than 0.25 wt.% water when exposed to 80% relative humidity at room temperature.

scholarly journals Selection of the chemical composition of steels and their thermal hardening mode using a computer program

2021 ◽  
pp. 59-65
Author(s):  
D. M. Berdiev ◽  
M. A. Uмаrоvа ◽  
A. A. Yusupov
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Computer Program ◽  
Sliding Friction ◽  
Thermal Hardening ◽  
Abrasive Particles ◽  
Density Of Dislocations ◽  
Heat Treated ◽  
Final Tempering ◽  
Selection Of

The relationships between the parameters of the structure of heat‑treated steels and their abrasive wear resistance are established. At all temperatures of the final tempering of hardened steel, there is a direct relationship between its structure parameters (the number of elements in a solid solution, the density of dislocations, the size of cementite particles and the intercementite distance) and wear resistance when sliding friction against loose abrasive particles. A computer program has been developed to select the chemical composition of the steel grade and methods of thermal hardening in order to ensure the required wear resistance.

scholarly journals Quasiparticle effects on the linear and nonlinear susceptibility of ZnGeP2

RSC Advances ◽  
2019 ◽  
Vol 9 (61) ◽  
pp. 35771-35779
Author(s):  
Hua Xie ◽  
Shenghao Fang ◽  
He Zhao ◽  
Xiaoliang Xu ◽  
Ning Ye ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Nonlinear Optics ◽  
Nonlinear Optical ◽  
High Thermal Conductivity ◽  
Nonlinear Susceptibility ◽  
Optical Coefficient ◽  
Linear And Nonlinear ◽  
Nonlinear Optical Coefficient

The semiconductor zinc germanium diphosphide (ZnGeP2) has wide applications in the infrared nonlinear optics (NLO) due to its high nonlinear optical coefficient, wide infrared transparency range and high thermal conductivity.

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