Structures and Properties of Sophorolipids in Dependence of Microbial Strain, Lipid Substrate and Post-Modification

2019 ◽  
Vol 56 (5) ◽  
pp. 367-377
Author(s):  
Timo Bollmann ◽  
Christian Zerhusen ◽  
Birgit Glüsen ◽  
Ulrich Schörken
Keyword(s):  
Structures And Properties ◽  
Post Modification ◽  
Microbial Strain ◽  
Lipid Substrate

Effects of Substituting B2O3 for P2O5 on the Structures and Properties of V2O5-P2O5 Glass Systems (II)

2015 ◽  
Vol 53 (3) ◽  
pp. 198-205
Author(s):  
Bong-Ki Ryu ◽  
Su-Yeon Choi ◽  
Young-Seok Kim ◽  
Jong-Hwan Kim ◽  
Jae-Yeop Jung ◽  
...  
Keyword(s):  
Structures And Properties

SuFExable Polymers with Helical Structures Derived from Thionyl Tetrafluoride (SOF4)

2019 ◽  
Author(s):  
Suhua Li ◽  
Gencheng Li ◽  
Bing Gao ◽  
Sidharam P. Pujari ◽  
Xiaoyan Chen ◽  
...  
Keyword(s):  
Functional Polymers ◽  
Polymer Chains ◽  
New Materials ◽  
Helical Structures ◽  
Polymer Backbone ◽  
Silyl Ethers ◽  
Helical Polymer ◽  
Key Characteristics ◽  
Post Modification ◽  
Individual Polymer

The first SuFEx click chemistry synthesis of SOF<sub>4</sub>-derived copolymers based upon the polymerization of bis(iminosulfur oxydifluorides) and bis(aryl silyl ethers) is described. This novel class of SuFEx polymer presents two key characteristics: First, the newly created [-N=S(=O)F-O-] polymer backbone linkages are themselves SuFExable and primed to undergo further high-yielding and precise SuFEx-based post-modification with phenols or amines to yield branched functional polymers. Second, studies of individual polymer chains of several of these new materials indicate the presence of helical polymer structures, which itself suggests a preferential approach of new monomers onto the growing polymer chain upon the formation of the stereogenic linking moiety.

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

Structures and Properties of Rubberlike Networks

1997 ◽  
Author(s):  
Burak Erman ◽  
James E. Mark
Keyword(s):  
Subject Matter ◽  
Rubber Elasticity ◽  
Polymer Science ◽  
Strong Emphasis ◽  
Present Book ◽  
Structures And Properties

Rubber elasticity is an important sub-field of polymer science. This book is in many ways a sequel to the authors' previous, more introductory book, Rubberlike Elasticity: A Molecular Primer (Wiley-Interscience, 1988), and will in some respects replace the now classic book by L.R.G. Treloar, The Physics of Rubber Elasticity (Oxford, 1975). The present book has much in common with its predecessor, in particular its strong emphasis on molecular concepts and theories. Similarly, only equilibrium properties are covered in any detail. Though this book treats much of the same subject matter, it is a more comprehensive, more up-to-date, and somewhat more sophisticated treatment.

Star-shaped arylacetylene resins derived from silicon

2020 ◽  
Vol 40 (8) ◽  
pp. 676-684
Author(s):  
Niping Dai ◽  
Junkun Tang ◽  
Manping Ma ◽  
Xiaotian Liu ◽  
Chuan Li ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Mechanical Test ◽  
Flexural Modulus ◽  
Mechanical Analysis ◽  
Reinforced Composites ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Structures And Properties ◽  
High Performance Resin

AbstractStar-shaped arylacetylene resins, tris(3-ethynyl-phenylethynyl)methylsilane, tris(3-ethynyl-phenylethynyl) phenylsilane, and tris (3-ethynyl-phenylethynyl) silane (TEPHS), were synthesized through Grignard reaction between 1,3-diethynylbenzene and three types of trichlorinated silanes. The chemical structures and properties of the resins were characterized by means of nuclear magnetic resonance, fourier-transform infrared spectroscopy, Haake torque rheomoter, differential scanning calorimetry, dynamic mechanical analysis, mechanical test, and thermogravimetric analysis. The results show that the melt viscosity at 120 °C is lower than 150 mPa⋅s, and the processing windows are as wide as 60 °C for the resins. The resins cure at the temperature as low as 150 °C. The good processabilities make the resins to be suitable for resin transfer molding. The cured resins exhibit high flexural modulus and excellent heat-resistance. The flexural modulus of the cured TEPHS at room temperature arrives at as high as 10.9 GPa. Its temperature of 5% weight loss (Td5) is up to 697 °C in nitrogen. The resins show the potential for application in fiber-reinforced composites as high-performance resin in the field of aviation and aerospace.

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