Boronic acids as building blocks for molecular nanostructures and polymeric materials

2009 ◽  
pp. 5254 ◽  
Author(s):  
Kay Severin
Keyword(s):  
Polymeric Materials ◽  
Building Blocks ◽  
Boronic Acids ◽  
Molecular Nanostructures

scholarly journals Catalytic enantioselective synthesis of α-aryl α-hydrazino esters and amides

2020 ◽  
Vol 56 (43) ◽  
pp. 5823-5826
Author(s):  
Marta Velázquez ◽  
Saúl Alberca ◽  
Javier Iglesias-Sigüenza ◽  
Rosario Fernández ◽  
José M. Lassaletta ◽  
...  
Keyword(s):  
Building Blocks ◽  
Boronic Acids ◽  
Enantioselective Synthesis

Asymmetric 1,2-addition of aryl boronic acids to N-carbamoyl (Cbz and Fmoc) protected glyoxylate-derived hydrazones affords α-aryl α-hydrazino esters/amides, key building blocks en route to artificial peptides.

Recent aspects of self-oscillating polymeric materials: designing self-oscillating polymers coupled with supramolecular chemistry and ionic liquid science

2014 ◽  
Vol 16 (22) ◽  
pp. 10388-10397 ◽  
Author(s):  
Takeshi Ueki ◽  
Ryo Yoshida
Keyword(s):  
Ionic Liquid ◽  
Supramolecular Chemistry ◽  
Polymeric Materials ◽  
Building Blocks ◽  
Covalent Bonds ◽  
Spatiotemporal Structure ◽  
Molecular Building Blocks ◽  
Recent Developments

Herein, we summarise the recent developments in self-oscillating polymeric materials based on the concepts of supramolecular chemistry, where aggregates of molecular building blocks with non-covalent bonds evolve the temporal or spatiotemporal structure.

SYNTHESIS AND CHARACTERIZATION OF SELF-HEALING MORTAR WITH MODIFIED STRENGTH

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Gassan Fahim Huseien ◽  
Jahangir Mirza ◽  
Nur Farhayu Ariffin ◽  
Mohd Warid Hussin
Keyword(s):  
Early Stage ◽  
Polymeric Materials ◽  
Building Blocks ◽  
Ultrasonic Pulse Velocity ◽  
Cementitious Materials ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Diglycidyl Ether ◽  
Self Healing ◽  
Research Initiative

Cementitious materials being the most prospective building blocks achieving their absolute strength to avoid the deterioration in the early stage of service life is ever-demanding. Minimizing the labor and capital-intensive maintenance and repair cost is a critical challenge. Thus, self-healing mortars with modified strength are proposed. Lately, self-healing of micro-cracks by introducing bacteria during the formation of mortar or concrete became attractive. Self-healing with polymeric admixtures is considered to be relatively more durable and faster process. Certainly, the self-healing of synthetic polymeric materials is inspired by biological systems, where the damage triggers an autonomic healing response. This emerging and fascinating research initiative may significantly improve the durability and the safety limit of the polymeric components potential for assorted applications. In this work, using epoxy resin (diglycidyl ether of bisphenol A) without any hardener as admixture polymeric-cementitious materials is prepared. These epoxy-modified mortars are synthesized with various polymer-cement ratios subjected to initial wet/dry curing (WDC) together with long term dry curing (DC). Their self-healing function and hardening effects are evaluated via preloading and drying of the specimens, chemical analysis, and ultrasonic pulse velocity testing. It is demonstrated that 10% of polymer is the best proportion for polymer-cement ratio. Furthermore, the wet/dry curing is established to be superior process for healing hairline cracks present in the mortar. The excellent features of the results suggest that our novel method may constitute a basis for improving the compressive strength and self-healing features of mortars.    

Hierarchical supramolecules and organization using boronic acid building blocks

2015 ◽  
Vol 51 (11) ◽  
pp. 2005-2020 ◽  
Author(s):  
Yuji Kubo ◽  
Ryuhei Nishiyabu ◽  
Tony D. James
Keyword(s):  
Smart Materials ◽  
Boronic Acid ◽  
Building Blocks ◽  
Boronic Acids ◽  
Feature Article

Current progress on hierarchical supramolecules using boronic acids has been highlighted in this feature article. The feasibility of the structure-directing ability is fully discussed from the standpoint of the generation of new smart materials.

scholarly journals The Green Approach to the Synthesis of Bio-Based Thermoplastic Polyurethane Elastomers with Partially Bio-Based Hard Blocks

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2334
Author(s):  
Ewa Głowińska ◽  
Paulina Kasprzyk ◽  
Janusz Datta
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Polyurethane ◽  
Viscoelastic Behavior ◽  
Polymeric Materials ◽  
Building Blocks ◽  
Chain Extender ◽  
Sustainable Chemistry ◽  
Polyurethane Elastomers ◽  
Thermoplastic Polyurethane Elastomers ◽  
Hard Segments

Bio-based polymeric materials and green routes for their preparation are current issues of many research works. In this work, we used the diisocyanate mixture based on partially bio-based diisocyanate origin and typical petrochemical diisocyanate for the preparation of novel bio-based thermoplastic polyurethane elastomers (bio-TPUs). We studied the influence of the diisocyanate mixture composition on the chemical structure, thermal, thermomechanical, and mechanical properties of obtained bio-TPUs. Diisocyanate mixture and bio-based 1,4-butanediol (as a low molecular chain extender) created bio-based hard blocks (HS). The diisocyanate mixture contained up to 75 wt % of partially bio-based diisocyanate. It is worth mentioning that the structure and amount of HS impact the phase separation, processing, thermal or mechanical properties of polyurethanes. The soft blocks (SS) in the bio-TPU’s materials were built from α,ω-oligo(ethylene-butylene adipate) diol. Hereby, bio-TPUs differed in hard segments content (c.a. 30; 34; 40, and 53%). We found that already increase of bio-based diisocyanate content of the bio-TPU impact the changes in their thermal stability which was measured by TGA. Based on DMTA results we observed changes in the viscoelastic behavior of bio-TPUs. The DSC analysis revealed decreasing in glass transition temperature and melting temperature of hard segments. In general, obtained materials were characterized by good mechanical properties. The results confirmed the validity of undertaken research problem related to obtaining bio-TPUs consist of bio-based hard building blocks. The application of partially bio-based diisocyanate mixtures and bio-based chain extender for bio-TPU synthesis leads to sustainable chemistry. Therefore the total level of “green carbons” increases with the increase of bio-based diisocyanate content in the bio-TPU structure. Obtained results constitute promising data for further works related to the preparation of fully bio-based thermoplastic polyurethane elastomers and development in the field of bio-based polymeric materials.

The Materials World Module Series and the Polymer Module: A Design-Oriented Approach to Teach Scientific Concepts to Grades 9-12 Students through Materials Science

2001 ◽  
Vol 684 ◽  
Author(s):  
SonBinh T. Nguyen ◽  
Jennifer K. Cocson ◽  
Carol L. Colby ◽  
Robert P. H. Chang ◽  
Keith E. Miller
Keyword(s):  
High School ◽  
High School Students ◽  
Science Curriculum ◽  
Polymeric Materials ◽  
Building Blocks ◽  
Modern World ◽  
Poly Vinyl Alcohol ◽  
Scientific Concepts ◽  
School Students ◽  
Polymer Properties

ABSTRACTThe Materials World Modules (MWM), funded by the National Science Foundation, is a series of nine short texts that introduce science and scientific concepts to high school students through guided investigations of the materials that surrounds us in the modern world. Designed to be flexible, these modules can be incorporated into a high school science curriculum as a learning-by-inquiry addition to the main science texts. Depending on the time that the teacher has, each module can be covered in 8 to 15 class periods. Using an inquiry method of learning, the modules prompt the students to generate questions about a subject and find experimental approaches which will lead them to the answers. The modules encourage the students to learn by carrying out simple experiments using readily available materials. The Polymers Module of the MWM series aims at introducing the concepts of polymer chemistry and polymeric materials to an audience that has had some exposure to general chemistry. It asks the students to investigate their surroundings to find polymer-based objects and to infer the properties of those objects from knowing the structures of the monomeric building blocks. It introduces the relation between polymer properties and structure and that between polymer properties and molecular weight by suggesting experiments that students can do with poly(vinyl alcohol) and poly(vinyl acetate) films. Finally, it encourages the students to use what they have learned to design simple devices using polymeric materials. An example of such a device is a humidity sensor that is fabricated from thin polymer films.

scholarly journals Principles of molecular assemblies leading to molecular nanostructures

2013 ◽  
Vol 371 (2000) ◽  
pp. 20120304 ◽  
Author(s):  
Kunal S. Mali ◽  
Steven De Feyter
Keyword(s):  
Self Assembly ◽  
Contemporary Literature ◽  
High Vacuum ◽  
Building Blocks ◽  
Ultra High Vacuum ◽  
Two Dimensional ◽  
Ambient Conditions ◽  
Solid Interface ◽  
Metal Organic ◽  
Molecular Nanostructures

Self-assembled physisorbed monolayers consist of regular two-dimensional arrays of molecules. Two-dimensional self-assembly of organic and metal–organic building blocks is a widely used strategy for nanoscale functionalization of surfaces. These supramolecular nanostructures are typically sustained by weak non-covalent forces such as van der Waals, electrostatic, metal–ligand, dipole–dipole and hydrogen bonding interactions. A wide variety of structurally very diverse monolayers have been fabricated under ambient conditions at the liquid–solid and air–solid interface or under ultra-high-vacuum (UHV) conditions at the UHV–solid interface. The outcome of the molecular self-assembly process depends on a variety of factors such as the nature of functional groups present on assembling molecules, the type of solvent, the temperature at which the molecules assemble and the concentration of the building blocks. The objective of this review is to provide a brief account of the progress in understanding various parameters affecting two-dimensional molecular self-assembly through illustration of some key examples from contemporary literature.

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