Synthesis and Characterization of Ionically Cross-linked Networks Through the Use of Ion-pair Comonomers

Synthesis and Characterization of Ionically Cross-linked Networks Through the Use of Ion-pair Comonomers
Author: Guodong Deng
Publisher:
Total Pages: 0
Release: 2018
Genre: Acrylates
ISBN:

Structurally dynamic polymer networks, which can break and reform under external stimuli (e.g. heat, mechanical stress, light, etc.) have emerged as a useful approach to fabricate stimuli-responsive polymers (SRPs). One general route to introduce dynamic bonds is through non-covalent supramolecular interactions. Ion-pairing, is another potential non-covalent dynamic bond distinct from other interactions like hydrogen bonding and metal-ligand interactions. In this study, we demonstrate a new route to prepare structurally dynamic polymer networks by direct copolymerization of organic ion-pair comonomers (IPCs) with n-butyl acrylate (BA). A series of these copolymers were prepared and their results of rheological, mechanical, thermal and morphological behaviors will be comprehensively studied to understand the structure-property relationships. Firstly, a phosphonium-based IPC was synthesized and copolymerized with BA to prepare polyampholyte ionomers. Evidence of microphase separation of the ion-pairs to produce vitrified ion-rich domains acting as physical cross-links was found in polyampholyte ionomers by rheological and atomic force microscopy measurements. Comparison to analogous cationic and anionic ionomers with pendant counter-ions demonstrated the strong impact of direct ion-pair cross-linking on the material's viscoelastic properties. Characterization of the corresponding polyelectrolytes showed a ca. 125 oC increase in the glass transition temperature (Tg) from the cationic to the polyampholytic polyelectrolyte. This elevated Tg allowed the vitrification of the ion-rich domains at ambient temperatures in the polyampholyte networks over a range of ion-pair concentrations. An increase in molecular weight could lead to highly entangled samples, which displayed an improved mechanical properties. Secondly, the copolymers of the ion-pair co-monomer and cationic monomer were found to effectively plasticize the synthesized polyampholytic polyelectrolyte and tune their Tg. This plasticizing effect could also be applied to the polyampholyte ionomers through the copolymerization of BA and ionic monomers blends. In this way, the Tg of vitrified ion-rich domains in polyampholyte ionomers can be approximately predicted with IPC concentration, which opens up the toolbox for designing SPRs with varying transition temperature. Thirdly, an analogous ammonium-based IPC was also synthesized and used to prepare polyampholyte ionomers. Comparison to analogous phosphonium-based polyampholyte ionomers demonstrated a stronger ion-pair interaction and weaker thermal stability in ammonium/sulfonate than phosphonium/sulfonate. This novel IPC can expand the IPCs' library and fine tune viscoelastic behavior of polyampholyte ionomers systems with less expensive starting materials.

Hydrogels Based on Natural Polymers

Hydrogels Based on Natural Polymers
Author: Yu Chen
Publisher: Elsevier
Total Pages: 552
Release: 2019-10-23
Genre: Technology & Engineering
ISBN: 0128166185

Hydrogels Based on Natural Polymers presents the latest research on natural polymer-based hydrogels, covering fundamentals, preparation methods, synthetic pathways, advanced properties, major application areas, and novel characterization techniques. The advantages and disadvantages of each natural polymer-based hydrogel are also discussed, enabling preparation tactics for specific properties and applications. Sections cover fundamentals, development, characteristics, structures and properties. Additional chapters cover presentation methods and properties based on natural polymers, including physical and chemical properties, stimuli-responsive properties, self-healing properties, and biological properties. The final section presents major applications areas, including the biomedical field, agriculture, water treatments, and the food industry. This is a highly valuable resource for academic researchers, scientists and advanced students working with hydrogels and natural polymers, as well as across the fields of polymer science, polymer chemistry, plastics engineering, biopolymers and biomaterials. The detailed information will also be of great interest to scientists and R&D professionals, product designers, technicians and engineers across industries. Provides systematic coverage of all aspects of hydrogels based on natural polymers, including fundamentals, preparation methods, properties and characterization Offers a balanced assessment of the specific properties and possibilities offered by different natural polymer-based hydrogels, drawing on innovative research Examines cutting-edge applications across biomedicine, agriculture, water treatments, and the food industry

Polyampholytes

Polyampholytes
Author: Sarkyt E. Kudaibergenov
Publisher: Springer Science & Business Media
Total Pages: 232
Release: 2002-04-30
Genre: Science
ISBN: 9780306467813

This book comprehensively reviews the synthesis, characterization and application aspects of linear and crosslinked synthetic polyampholytes - simple model of biopolymers - starting from the 1950's. The synthetic strategy of "annealed", "quenched" and "zwitterionic" polyampholytes, the properties of polyampholytes in solutions and in gel state are considered. The complexation ability of polyampholytes with respect to transition metal ions, ionic surfactants, dyes and organic probes polyelectrolytes, proteins and colloid particles is discussed. Stimuli-sensitive behavior of various amphoteric gel and membrane systems demonstrating rhythmically phenomenon similar to that of heart beat, deformation, oscillation or self-oscillation phenomena stimulated by temperature, pH and electric field are illustrated. Catalytic properties of synthetic polyampholytes simulating the function of enzymes are also considered.

Porous Polymers

Porous Polymers
Author: Michael S. Silverstein
Publisher: John Wiley & Sons
Total Pages: 480
Release: 2011-04-19
Genre: Technology & Engineering
ISBN: 0470390840

This book gathers the various aspects of the porous polymer field into one volume. It not only presents a fundamental description of the field, but also describes the state of the art for such materials and provides a glimpse into the future. Emphasizing a different aspect of the ongoing research and development in porous polymers, the book is divided into three sections: Synthesis, Characterization, and Applications. The first part of each chapter presents the basic scientific and engineering principles underlying the topic, while the second part presents the state of the art results based on those principles. In this fashion, the book connects and integrates topics from seemingly disparate fields, each of which embodies different aspects inherent in the diverse field of porous polymeric materials.

The Physical Chemistry of Materials

The Physical Chemistry of Materials
Author: Rolando Roque-Malherbe
Publisher: CRC Press
Total Pages: 524
Release: 2016-04-19
Genre: Science
ISBN: 1420082736

In recent years, the area dealing with the physical chemistry of materials has become an emerging discipline in materials science that emphasizes the study of materials for chemical, sustainable energy, and pollution abatement applications. Written by an active researcher in this field, Physical Chemistry of Materials: Energy and Environmental Appl

Cellulose-Based Superabsorbent Hydrogels

Cellulose-Based Superabsorbent Hydrogels
Author: Md. Ibrahim H. Mondal
Publisher: Springer
Total Pages: 0
Release: 2019-02-22
Genre: Technology & Engineering
ISBN: 9783319778297

With the prospect of revolutionizing specific technologies, this book highlights the most exciting and impactful current research in the fields of cellulose-based superabsorbent hydrogels with their smart applications. The book assembles the newest synthetic routes, characterization methods, and applications in the emergent area. Leading experts in the field have contributed chapters representative of their most recent research results, shedding light on the enormous potential of this field and thoroughly presenting cellulose-based hydrogel functioning materials. The book is intended for the polymer chemists, academic and industrial scientists and engineers, pharmaceutical and biomedical scientists and agricultural engineers engaged in research and development on absorbency, absorbent products and superabsorbent hydrogels. It can also be supportive for undergraduate and graduate students.

Studies on Porous Monolithic Materials Prepared via Sol–Gel Processes

Studies on Porous Monolithic Materials Prepared via Sol–Gel Processes
Author: George Hasegawa
Publisher: Springer Science & Business Media
Total Pages: 214
Release: 2012-10-03
Genre: Technology & Engineering
ISBN: 4431541985

This thesis focuses on porous monolithic materials that are not in the forms of particles, fibers, or films. In particular, the synthetic strategy of porous monolithic materials via the sol–gel method accompanied by phase separation, which is characterized as the non-templating method for tailoring well-defined macropores, is described from the basics to actual synthesis. Porous materials are attracting more and more attention in various fields such as electronics, energy storage, catalysis, sensing, adsorbents, biomedical science, and separation science. To date, many efforts have been made to synthesize porous materials in various chemical compositions—organics, inorganics including metals, glasses and ceramics, and organic-inorganic hybrids. Also demonstrated in this thesis are the potential applications of synthesized porous monolithic materials to separation media as well as to electrodes for electric double-layer capacitors (EDLCs) and Li-ion batteries (LIBs). This work is ideal for graduate students in materials science and is also useful to engineers or scientists seeking basic knowledge of porous monolithic materials.

Polysaccharide Hydrogels

Polysaccharide Hydrogels
Author: Pietro Matricardi
Publisher: CRC Press
Total Pages: 527
Release: 2016-01-05
Genre: Medical
ISBN: 9814613622

Hydrogels are an emerging area of interest in medicine as well as pharmaceutics, and their physico-chemical characterization is fundamental to their practical applications. Compared with synthetic polymers, polysaccharides that are widely present in living organisms and come from renewable sources are extremely advantageous for hydrogel formation.

Rheology of Industrial Polysaccharides: Theory and Applications

Rheology of Industrial Polysaccharides: Theory and Applications
Author: R. Lapasin
Publisher: Springer Science & Business Media
Total Pages: 633
Release: 2012-12-06
Genre: Science
ISBN: 1461521858

fudustrial uses of polysaccharides centre on their ability to thicken or structure many times their own weight of water, or in other words to control the rheology of hydrated systems. Until comparatively recently, however, objective characterisation of polysaccharide rheology, except in a few specialist research laboratories, was largely confined to compression of gels, simple measurements of solution viscosity, often in ill-defined geometries, and imitative tests intended to reflectproductperformance in specific areas ofend-use. Several factors have combined to bring a wider range of rheological techniques into common use. One is the increasing practical importance of systems that cannot adequately be described as solids or liquids, such as 'weak gels' and spreadable pastes. fu parallel, routine characterisation of such systems has become economically feasible with the development of a new generation of comparatively inexpensive computer-controlled instruments. There has also been a change ofemphasis from phenomenologicaldescription ofproduct texture towards the use of rheological measurements to probe the underlying molecular and supramolecular structures and the processes by which they are formed. As a result, even the most pragmatic producers and users of industrial polysaccharides are probably now familiar with terms such as creep compliance, stress overshoot and the ubiquitous G' and G", although perhaps not fully understanding their precise meaning or practical significance. A definitive text giving a rigorous description of the rheological approaches relevant to polysaccharide systems is therefore appropriate and timely. Romano Lapasin and Sabrina Priel are to be congratulated for tackling the daunting but worthwhile taskofproducing such avolume.