Lanthanide dodecyl sulfates, a potent family of catalysts for the preparation of biobased epoxy thermosetting polymers

2021 ◽  
Author(s):  
Forouzan Kazemi ◽  
Louis Schutz ◽  
Jean-Yves Bergeron ◽  
Eric Gagnon ◽  
Glenn P A Yap ◽  
...  
Keyword(s):  
Solid States ◽  
Thermosetting Polymers

Lanthanide dodecyl sulfates, LnDSx, are remarkably effective to catalyze the reaction of diepoxides with diamines in the liquid and solid states, the key reaction in the formation of epoxy thermosets....

scholarly journals Micromechanical Punching: A Versatile Method for Non-Spherical Microparticle Fabrication

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 83
Author(s):  
Ritika Singh Petersen ◽  
Anja Boisen ◽  
Stephan Sylvest Keller
Keyword(s):  
Drug Delivery ◽  
High Resolution ◽  
Physicochemical Properties ◽  
High Throughput ◽  
Liquid State ◽  
Soft Lithography ◽  
Glycolic Acid ◽  
Thermosetting Polymers ◽  
Spherical Microparticle ◽  
Spherical Microparticles

Microparticles are ubiquitous in applications ranging from electronics and drug delivery to cosmetics and food. Conventionally, non-spherical microparticles in various materials with specific shapes, sizes, and physicochemical properties have been fabricated using cleanroom-free lithography techniques such as soft lithography and its high-resolution version particle replication in non-wetting template (PRINT). These methods process the particle material in its liquid/semi-liquid state by deformable molds, limiting the materials from which the particles and the molds can be fabricated. In this study, the microparticle material is exploited as a sheet placed on a deformable substrate, punched by a robust mold. Drawing inspiration from the macro-manufacturing technique of punching metallic sheets, Micromechanical Punching (MMP) is a high-throughput technique for fabrication of non-spherical microparticles. MMP allows production of microparticles from prepatterned, porous, and fibrous films, constituting thermoplastics and thermosetting polymers. As an illustration of application of MMP in drug delivery, flat, microdisk-shaped Furosemide embedded poly(lactic-co-glycolic acid) microparticles are fabricated and Furosemide release is observed. Thus, it is shown in the paper that Micromechanical punching has potential to make micro/nanofabrication more accessible to the research and industrial communities active in applications that require engineered particles.

scholarly journals Un-jamming due to energetic instability: statics to dynamics

2021 ◽  
Vol 23 (4) ◽  
Author(s):  
Stefan Luding ◽  
Yimin Jiang ◽  
Mario Liu
Keyword(s):  
Granular Matter ◽  
Numerical Data ◽  
Soft Materials ◽  
Material Point ◽  
Solid States ◽  
Granular Gas ◽  
Granular Solid Hydrodynamics ◽  
Particle Simulations ◽  
Points Of View ◽  
Deformation Modes

Abstract Jamming/un-jamming, the transition between solid- and fluid-like behavior in granular matter, is an ubiquitous phenomenon in need of a sound understanding. As argued here, in addition to the usual un-jamming by vanishing pressure due to a decrease of density, there is also yield (plastic rearrangements and un-jamming that occur) if, e.g., for given pressure, the shear stress becomes too large. Similar to the van der Waals transition between vapor and water, or the critical current in superconductors, we believe that one mechanism causing yield is by the loss of the energy’s convexity (causing irreversible re-arrangements of the micro-structure, either locally or globally). We focus on this mechanism in the context of granular solid hydrodynamics (GSH), generalized for very soft materials, i.e., large elastic deformations, employing it in an over-simplified (bottom-up) fashion by setting as many parameters as possible to constant. Also, we complemented/completed GSH by using various insights/observations from particle simulations and calibrating some of the theoretical parameters—both continuum and particle points of view are reviewed in the context of the research developments during the last few years. Any other energy-based elastic-plastic theory that is properly calibrated (top-down), by experimental or numerical data, would describe granular solids. But only if it would cover granular gas, fluid, and solid states simultaneously (as GSH does) could it follow the system transitions and evolution through all states into un-jammed, possibly dynamic/collisional states—and back to elastically stable ones. We show how the un-jamming dynamics starts off, unfolds, develops, and ends. We follow the system through various deformation modes: transitions, yielding, un-jamming and jamming, both analytically and numerically and bring together the material point continuum model with particle simulations, quantitatively. Graphic abstract

scholarly journals High-Speed 3D Printing of High-Performance Thermosetting Polymers via Two-Stage Curing

2018 ◽  
Vol 39 (7) ◽  
pp. 1700809 ◽  
Author(s):  
Xiao Kuang ◽  
Zeang Zhao ◽  
Kaijuan Chen ◽  
Daining Fang ◽  
Guozheng Kang ◽  
...  
Keyword(s):  
3D Printing ◽  
High Speed ◽  
High Performance ◽  
Two Stage ◽  
Thermosetting Polymers

Regioisomeric AIE-active luminogens with a substituent aldehyde group for controllable and reversible photochromic behavior and sensitive fluorescence detection of hydrogen sulfite

2021 ◽  
Vol 9 (11) ◽  
pp. 3882-3891
Author(s):  
Hai-Xia Yu ◽  
Junge Zhi ◽  
Jin-Liang Wang
Keyword(s):  
Fluorescence Detection ◽  
Aldehyde Group ◽  
Photochromic Behavior ◽  
Solid States

Three simple AIE-active molecules displayed obvious photoactive behaviors in both solution and solid states and selective sensing of hydrogen sulfite.

scholarly journals Nonthermal Transport of Energy Driven by Photoexcited Carriers in Switchable Solid States of GeTe

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
R. Gu ◽  
T. Perrault ◽  
V. Juvé ◽  
G. Vaudel ◽  
M. Weis ◽  
...  
Keyword(s):  
Solid States

scholarly journals A review on allotropes of carbon and natural filler-reinforced thermomechanical properties of upgraded epoxy hybrid composite

2021 ◽  
Vol 60 (1) ◽  
pp. 237-275
Author(s):  
Krushna Gouda ◽  
Sumit Bhowmik ◽  
Biplab Das
Keyword(s):  
Hybrid Composite ◽  
Low Cost ◽  
Extraction Process ◽  
Thermomechanical Properties ◽  
Neat Epoxy ◽  
Inorganic Filler ◽  
Nonrenewable Resource ◽  
High Performing ◽  
Thermosetting Polymers ◽  
Natural Filler

Abstract The scarcity of nonrenewable resource motivated inclination towards the environmental-friendly novel materials and development of waste natural filler-based hybrid composite is encouraged to fulfill the material demand. Epoxy resins-based composites are high-performing thermosetting polymers and have outstanding blending properties, good machinability, and low cost. Due to these advantages, thermoset plastic is largely used in a broad range of engineering applications; however, thermomechanical properties of neat epoxy are low. Thus, to enhance the thermomechanical properties of epoxy, it is interfaced materials such as graphite, graphene nanoplatelet, boron, carbon fiber, aluminium, silver, etc. Among various substances, graphene has been deliberated as an acceptable novel filler because of its exceptional properties. In addition to inorganic filler inclusion, natural filler/fiber like hemp, sisal, flax, bamboo, jute, etc. can be utilized in a higher percentage as biodegradable material. The present article assisted to improve thermomechanical properties of neat epoxy. This work identifies and addresses (i) processes used for graphene modification; (ii) treatment utilized for enhancing the binding properties of natural filler; (iii) various natural filler extraction process employed; (iv) neat epoxy modification; and (v) influence of different dimensions of fillers.

Glass transition temperature as a function of conversion in thermosetting polymers

1991 ◽  
Vol 24 (9) ◽  
pp. 2610-2621 ◽  
Author(s):  
Arturo Hale ◽  
Christopher W. Macosko ◽  
Harvey E. Bair
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermosetting Polymers
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