Designing Soft Reactive Adhesives by Controlling Polymer Chemistry

AbstractSoft reactive adhesives (SRAs) are polymer-based materials (e.g., polyurethanes, polysiloxanes, polydienes) designed to be further vulcanized or slightly cross-linked through external activation (heat, moisture, oxygen, UV–visible irradiation, etc.), either at the time of their application or within a subsequent predefined period. They are used mainly as mastics, or sealing compounds, in a wide range of industrial and commercial fields such as construction, footwear, and the automotive industry. Generally deposited as thick films, SRAs behave as structural adhesives; their low elastic moduli accommodate large strains between the bonded parts without incurring permanent damage. Other outstanding attributes of SRAs are their resistance to solvents, their ability to withstand aggressive environments, and their ease of use. This article discusses examples of SRAs and, more specifically, shows how the cross-linking chemistry, mainly through step-growth polymerization, provides their primary advantages.

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Polymer characterization

Polymer Chemistry ◽

10.1093/oso/9780198503095.003.0006 ◽

2004 ◽

Author(s):

Ian L. Hosier ◽

Alun S. Vaughan

Keyword(s):

Molecular Weight ◽

Electrode Materials ◽

Polymeric Materials ◽

Optical Nonlinearity ◽

Polymer Science ◽

New Materials ◽

Wide Range ◽

Step Growth ◽

Step Growth Polymerization ◽

Increasing Demand

Polymer science is, of course, driven by the desire to produce new materials for new applications. The success of materials such as polyethylene, polypropylene, and polystyrene is such that these materials are manufactured on a huge scale and are indeed ubiquitous. There is still a massive drive to understand these materials and improve their properties in order to meet material requirements; however, increasingly polymers are being applied to a wide range of problems, and certainly in terms of developing new materials there is much more emphasis on control. Such control can be control of molecular weight, for example, the production of polymers with a highly narrow molecular weight distribution by anionic polymerization. The control of polymer architecture extends from block copolymers to other novel architectures such as ladder polymers and dendrimers. Cyclic systems can also be prepared, usually these are lower molecular weight systems, although these also might be expected to be the natural consequence of step-growth polymerization at high conversion. Polymers are used in a wide range of applications, as coatings, as adhesives, as engineering and structural materials, for packaging, and for clothing to name a few. A key feature of the success and versatility of these materials is that it is possible to build in properties by careful design of the (largely) organic molecules from which the chains are built up. For example, rigid aromatic molecules can be used to make high-strength fibres, the most highprofile example of this being Kevlar®; rigid molecules of this type are often made by simple step-growth polymerization and offer particular synthetic challenges as outlined in Chapter 4. There is now an increasing demand for highly specialized materials for use in for example optical and electronic applications and polymers have been singled out as having particular potential in this regard. For example, there is considerable interest in the development of polymers with targeted optical properties such as second-order optical nonlinearity, and in conducting polymers as electrode materials, as a route towards supercapacitors and as electroluminescent materials. Polymeric materials can also be used as an electrolyte in the design of compact batteries.

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Engineering of Doxorubicin-Encapsulating and TRAIL-Conjugated Poly(RGD) Proteinoid Nanocapsules for Drug Delivery Applications

Polymers ◽

10.3390/polym12122996 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2996

Author(s):

Elad Hadad ◽

Safra Rudnick-Glick ◽

Ella Itzhaki ◽

Matan Y. Avivi ◽

Igor Grinberg ◽

...

Keyword(s):

Side Effects ◽

Self Assembly ◽

Tumor Therapy ◽

Ovarian Cancer Cells ◽

Chemotherapeutic Drug ◽

Enzyme Degradation ◽

Wide Range ◽

Step Growth ◽

Step Growth Polymerization ◽

Necrosis Factor

Proteinoids are non-toxic biodegradable polymers prepared by thermal step-growth polymerization of amino acids. Here, P(RGD) proteinoids and proteinoid nanocapsules (NCs) based on D-arginine, glycine, and L-aspartic acid were synthesized and characterized for targeted tumor therapy. Doxorubicin (Dox), a chemotherapeutic drug used for treatment of a wide range of cancers, known for its adverse side effects, was encapsulated during self-assembly to form Dox/P(RGD) NCs. In addition, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which can initiate apoptosis in most tumor cells but undergoes fast enzyme degradation, was stabilized by covalent conjugation to hollow P(RGD) NCs. The effect of polyethylene glycol (PEG) conjugation was also studied. Cytotoxicity tests on CAOV-3 ovarian cancer cells demonstrated that Dox/P(RGD) and TRAIL-P(RGD) NCs were as effective as free Dox and TRAIL with cell viability of 2% and 10%, respectively, while PEGylated NCs were less effective. Drug-bearing P(RGD) NCs offer controlled release with reduced side effects for improved therapy.

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From the history of the development of electronic dictionaries: foreign and domestic experience

Humanitarian studios: pedagogics, psychology, philosophy ◽

10.31548/hspedagog2020.01.006 ◽

2020 ◽

Vol 11 (1) ◽

pp. 6-12

Author(s):

O. Y. Balalaieva ◽

Keyword(s):

Human Activity ◽

Current Level ◽

Ease Of Use ◽

Advanced Search ◽

Wide Range ◽

Promising Area ◽

History Of ◽

Machine Readable ◽

Everyday Communication ◽

Educational Professional

The purpose of the article is to study the dynamics of electronic dictionaries development abroad and in Ukraine using methods of analysis of scientific sources, comparison, generalization and systematization. Electronic dictionaries have been found to be a relatively new phenomenon in the lexicographic market, evolving from machine-readable dictionaries, exact copies of paper editions to complex digital lexicographic systems with a powerful arsenal of functions over the decades. The stages of development of autonomous and online dictionaries are described. Electronic dictionaries due to the advanced search capabilities, speed, simplicity, ease of use, accessibility and compactness have gained popularity among a wide range of users. Today they are used in many spheres of human activity – scientific, educational, professional, everyday communication. However, the analysis of the current level of development of Ukrainian electronic resources indicates a shortage of electronic dictionaries both common and terminological vocabulary. The lack of electronic dictionaries is due to a number of objective problems, both practical and theoretical, that is why research in the field of domestic computer lexicography is a promising area of further research.

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Polymer Chemistry

10.1093/oso/9780198503095.001.0001 ◽

2004 ◽

Keyword(s):

Conducting Polymers ◽

Liquid Crystalline ◽

Polymer Chemistry ◽

Chain Growth ◽

Crystalline Polymers ◽

Wide Range ◽

Cyclic Oligomers ◽

Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

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Intramolecular Cyclization in Hyperbranched Star Copolymers via One-pot Am+Bn+C1 Step-growth Polymerization Resulting in Decreased Cyclic Defect

European Polymer Journal ◽

10.1016/j.eurpolymj.2021.110539 ◽

2021 ◽

pp. 110539

Author(s):

Qingfu Ban ◽

Yan Li ◽

Yusheng Qin ◽

Yaochen Zheng ◽

Jie Kong

Keyword(s):

Intramolecular Cyclization ◽

One Pot ◽

Star Copolymers ◽

Step Growth ◽

Step Growth Polymerization

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Synthesis and properties of a sterically encumbered poly(thienylene vinylene): poly[E-1,2-(4,4prime-dihexyl-2,2prime-dithienyl)ethylene]

Canadian Journal of Chemistry ◽

10.1139/v98-110 ◽

1998 ◽

Vol 76 (11) ◽

pp. 1524-1529

Author(s):

Jimmy Lowe ◽

Carl Bartels ◽

Steven Holdcroft

Keyword(s):

Ftir Spectroscopy ◽

Electrically Conducting ◽

H Nmr ◽

Visible Photoluminescence ◽

Micron Size ◽

Visible Irradiation ◽

Uv Visible ◽

The Stability ◽

Doped Polymer ◽

Polythiophene Derivative

Electrically conducting poly[E-1,2-(4,4prime-dihexyl-2,2prime-dithienyl)ethylene] was synthesized and structurally characterized by UV-visible, 1H NMR, and FTIR spectroscopy. The head-to-head arrangement of the alkylthiophene dyads directly affects the UV-visible, photoluminescence, and electroluminescence maxima of the polymer. The conductivity of the doped polymer was measured to be ~2 S cm-1 and the stability of the oxidized polymer possessing various dopants was compared. UV-visible irradiation of PDHDTE rendered the films insoluble and photolithography was used to produce micron-size images. FTIR was used to monitor the photoproducts during photolysis of PDHDTE. Mechanisms of photooxidation were proposed, based on the photoproducts observed.Key words: polythiophene derivative, head-to-head dyad, photolithography, photooxidation, electroluminescence.

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Mechanism pathway and kinetics of p-cresol photocatalytic degradation over titania nanorods under UV–visible irradiation

Chemical Engineering Journal ◽

10.1016/j.cej.2016.03.117 ◽

2016 ◽

Vol 296 ◽

pp. 420-427 ◽

Cited By ~ 16

Author(s):

Rattabal Khunphonoi ◽

Nurak Grisdanurak

Keyword(s):

Photocatalytic Degradation ◽

Visible Irradiation ◽

Uv Visible ◽

Kinetics Of

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Resin and carbon foam production by cationic step-growth polymerization of organic carbonates

Polymer Chemistry ◽

10.1039/c6py01572g ◽

2017 ◽

Vol 8 (2) ◽

pp. 404-413 ◽

Cited By ~ 3

Author(s):

L. Wöckel ◽

A. Seifert ◽

C. Mende ◽

I. Roth-Panke ◽

L. Kroll ◽

...

Keyword(s):

Carbon Dioxide ◽

Controlled Release ◽

Carbon Foam ◽

Organic Carbonates ◽

Step Growth ◽

Step Growth Polymerization ◽

Foam Production

Acid induced step-growth polymerizations of bis(p-methoxybenzyl) carbonate (pMBC), bis(m-methoxybenzyl) carbonate (mMBC) and difurfuryl carbonate (DFC) have been performed to produce resin-foams, because controlled release of carbon dioxide takes place during polymerization of those organic carbonates.

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