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.

scholarly journals Influence of the Glass Transition Temperature and the Density of Crosslinking Groups on the Reversibility of Diels-Alder Polymer Networks

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1189
Author(s):  
Merlina Thiessen ◽  
Volker Abetz
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Radical Polymerization ◽  
Polymer Networks ◽  
Alder Reaction ◽  
Diels Alder ◽  
Self Healing ◽  
Scanning Calorimetry ◽  
Diels Alder Reaction

The interest in self-healing, recyclable, and adaptable polymers is growing. This work addresses the reversibility of crosslink formation based on Diels-Alder reaction in copolymer networks containing furfuryl and maleimide groups, which represent the “diene” and the “dienophile,” respectively. The copolymers are synthesized by atom transfer radical polymerization (ATRP) and free radical polymerization. The diene bearing copolymers are crosslinked either with a small molecule containing two dienophiles or with a dienophile bearing copolymer. The influence of the crosslinking temperature on the Diels-Alder reaction is analyzed. Furthermore, the influence of the glass transition temperature and the influence of the density of crosslinking groups on the thermo-reversibility of crosslinking are investigated by temperature dependent infrared spectroscopy and differential scanning calorimetry. It is shown that the reversibility of crosslinking is strongly influenced by the glass transition temperature of the system.

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 High Glass‐Transition Temperature Polymer Networks Harnessing the Dynamic Ring Opening of Pinacol Boronates

2019 ◽  
Vol 58 (35) ◽  
pp. 12216-12222 ◽  
Author(s):  
Juliette Brunet ◽  
Franck Collas ◽  
Matthieu Humbert ◽  
Lionel Perrin ◽  
Fabrice Brunel ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ring Opening ◽  
Polymer Networks ◽  
High Glass Transition Temperature

Effects of Programming Temperature on the Efficiency of Self-Healing Polymers

2012 ◽  
Author(s):  
Yves Quentin Yougoubare ◽  
Ifeanyi Janarus Okoro ◽  
Su-Seng Pang
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Shape Recovery ◽  
Strength Properties ◽  
Self Healing ◽  
Test Results ◽  
Crack Healing ◽  
Micro Cracks ◽  
Intrinsic Correlation

Self-healing shape memory polymers possess the ability to heal macro and micro cracks by autonomic processes or when subjected to a suitable external stimulus. Recent advancements in the field have shown that the healing capabilities of self-healing polymers can be improved, thus yielding to high healing efficiencies. Depending on the application, the efficiency may refer to shape fixity, shape recovery ratio, dimensions recovery, strength regain, crack healing, etc. Based on test results, it is established that there is an intrinsic correlation between pre-strain levels, shape fixing and free shape recovery of samples programmed above the glass transition temperature (Tg). For samples programmed at multiple temperatures (above and below the glass transition temperature), the absence of lateral and 3D confinements lead to poor to no crack healing. Better compressive strength properties were, however, achieved by samples programmed at higher temperatures above Tg.

The Effects of Cross-Linking and Strain on the Glass Transition Temperature of a Polymer Network

1980 ◽  
Vol 53 (4) ◽  
pp. 982-987 ◽  
Author(s):  
M. A. Sharaf ◽  
J. E. Mark
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Polymer Network ◽  
Thermal Shrinkage ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
Increase With Increase ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Abstract The glass transition temperature Tg of an elastomer is of great importance with regard to its utilization since at this temperature and below, the material can no longer exhibit rubberlike behavior. In the present study, networks were prepared from atactic poly(vinyl acetate) and poly(isobutyl methacrylate), both types of networks being inherently non-crystallizable and therefore immune from complications associated with strain-induced crystallization. The values of Tg were obtained by dilatometry, differential scanning Calorimetry, the measurement of viscoelastic losses, and irreversible thermal shrinkage. For both types of networks, Tg was found to increase with increase in degree of crosslinking and with increase in elongation. These results suggest that the most important effect of crosslinking and network elongation is a decrease in the mobility or entropy of the network chains.

Mechanics and nanovoid nucleation dynamics: effects of polar functionality in glassy polymer networks

Soft Matter ◽  
2018 ◽  
Vol 14 (44) ◽  
pp. 8895-8911 ◽  
Author(s):  
Robert M. Elder ◽  
Tyler R. Long ◽  
Erich D. Bain ◽  
Joseph L. Lenhart ◽  
Timothy W. Sirk
Keyword(s):  
Fracture Toughness ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glassy Polymer ◽  
Polymer Networks ◽  
Molecular Simulations ◽  
High Glass Transition Temperature

We use molecular simulations and experiments to rationalize the properties of a class of networks based on dicyclopentadiene (DCPD), a polymer with excellent fracture toughness and a high glass transition temperature (Tg), copolymerized with 5-norbornene-2-methanol (NBOH).

scholarly journals High Glass‐Transition Temperature Polymer Networks Harnessing the Dynamic Ring Opening of Pinacol Boronates

2019 ◽  
Vol 131 (35) ◽  
pp. 12344-12350 ◽  
Author(s):  
Juliette Brunet ◽  
Franck Collas ◽  
Matthieu Humbert ◽  
Lionel Perrin ◽  
Fabrice Brunel ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ring Opening ◽  
Polymer Networks ◽  
High Glass Transition Temperature

Hardness of chemically densified Yellow birch in relation to wood density, polymer content and polymer properties

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Juliette Triquet ◽  
Pierre Blanchet ◽  
Véronic Landry
Keyword(s):  
Electron Beam ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Densified Wood ◽  
Indentation Modulus ◽  
Betula Alleghaniensis ◽  
Polymer Content ◽  
Yellow Birch ◽  
Polymer Properties

AbstractDensity of wood can be increased by filling its porous structure with polymers. Such densification processes aim to increase hardness of wood and are particularly interesting for flooring applications. This study aims to evaluate efficiency of different polymers for chemical densification based on the polymer properties. Yellow birch (Betula alleghaniensis Britt.) was chemically densified with seven monomer mixtures through acrylate monomer impregnation and electron beam in-situ polymerization. Chemical retention and polymer content of densified woods were recorded. Hardness of treated and untreated Yellow birch was measured and compared to hardness of Jatoba (Hymenaea courbaril L.). All densified woods showed higher or comparable hardness to Jatoba. Hardness of densified wood was analyzed in relation to initial density of wood and polymer content of the material using multivariable linear mixed models. Efficiency of polymers for chemical densification was evaluated through effect of polymer content on hardness with interaction coefficients. Polymer films corresponding to monomer impregnating mixtures were prepared through low energy electron beam and characterized by their glass transition temperature, micro hardness, indentation modulus and crosslinking density. Polymers showed statistically significantly different efficiencies and were separated in two main groups. Overall, polymer efficiency increased with increasing glass transition temperature of polyacrylates.

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