Novel crosslinking methods to design hydrogels

Structural engineering of polyurethane coatings for high performance applications

Isocyanate, and Non-isocyanate Polyurethane Etienne Delebecq,† Jean-Pierre Pascault,‡,§ Bernard Boutevin,† and Franco̧is Ganachaud*,†,‡,§ †Institut Charles Gerhardt, UMR 5253 CNRS, Ingeńierie et Architectures Macromolećulaires, Ecole Nationale Supeŕieure de Chimie de Montpellier, 8 rue de l’ećole normale, 34296 Montpellier, Cedex 05, France ‡INSA-Lyon, IMP, UMR5223, F-69621, Villeurbanne, France Universite ́ de Lyon, F-69622, Lyon, France

On the Versatility of Urethane/Urea Bonds: Reversibility, Blocked Isocyanate, and Non-isocyanate Polyurethane

The main objective of this review is to describe some of the important topics related to the use of marine and protective coatings for anticorrosive purposes. In this context, “protective” refers to coatings for containers, offshore constructions, wind turbines, storage tanks, bridges, rail cars, and petrochemical plants while “marine” refers to coatings for ballast tanks, cargo holds and cargo tanks, decks, and engine rooms on ships. The review aims at providing a thorough picture of state-of-the-art in anticorrosive coatings systems. International and national legislation aiming at reducing the emission of volatile organic compounds (VOCs) have caused significant changes in the anticorrosive coating industry. The requirement for new VOC-compliant coating technologies means that coating manufacturers can no longer rely on the extensive track record of their time-served products to convince consumers of their suitability for use. An important aspect in the development of new VOC-compliant, high-performance anticorrosive coating systems is a thorough knowledge of the components in anticorrosive coatings, their interactions, their advantages and limitations, as well as a detailed knowledge on the failure modes of anticorrosive coatings. This review, which mainly deals with European experience and practice, includes a description of the different environments an anticorrosive coating system may encounter during service. In addition, examples of test methods and standards for determination of the performance and durability of anticorrosive coatings have been included. The different types of anticorrosive coatings are presented, and the most widely applied generic types of binders and pigments in anticorrosive coatings are listed and described. Furthermore, the protective mechanisms of barrier, sacrificial, and inhibitive coatings are outlined. In the past decades, several alternatives to organic solvent-borne coatings have reached the commercial market. This review also presents some of these technologies and discusses some of their advantages and limitations. Finally, some of the mechanisms leading to degradation and failure of organic coating systems are described, and the reported types of adhesion loss are discussed.

Anticorrosive coatings: a review

Produced water is a complex mixture of organic and inorganic compounds and the largest volume of by-product generated during oil and gas recovery operations. The potential of oilfield produced water to be a source of fresh water for water-stressed oil-producing countries and the increasing environmental concerns in addition to stringent legislations on produced water discharge into the environment have made produced water management a significant part of the oil and gas business. This article reviews current technologies for the management of produced water, examines how electrochemical techniques may be used in these areas and compares the prospects for future development. It suggests that treatment technologies based on electrochemistry could be the future of produced water management, since produced water is a potential electrolyte because it has a relatively good conductivity. It also explains that by applying photoelectrochemistry, water electrolysis, fuel cell and electrodeposition, electrochemical engineering could achieve energy storage, production of clean water and recovery of valuable metals from produced water with minimal or no negative impact on the environment.

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Produced water treatment technologies

What are Coatings? Polymerization and Film Formation. Flow. Mechanical Properties. Exterior Durability. Adhesion. Corrosion Protection by Coatings. Latexes. Amino Resins. Binders Based on Isocyanates: Polyurethanes. Epoxy and Phenolic Resins. Acrylic Resins. Polyester Resins. Drying Oils. Alkyd Resins. Other Resins and Cross--Linkers. Solvents. Color and Appearance. Pigments. Pigment Dispersion. Pigment Volume Relationships. Application Methods. Film Defects. Solvent--Borne and High Solids Coatings. Water--Borne Coatings. Electrodeposition Coatings. Powder Coatings. Radiation Cure Coatings. Product Coatings for Metal Substrates. Product Coatings for Nonmetallic Substrates. Architectural Coatings. Special Purpose Coatings. Perspectives on Coatings Design. Appendix. Index.

Organic Coatings : Science and Technology

Nanosize poly(methyl methacrylate) (PMMA) microlatexes with high PMMA/surfactant ratio have been successfully prepared by a modified microemulsion polymerization, i.e., continuous and slow addition of monomer (MMA) to the polymerizing MMA microemulsion with mild stirring. Number-average diameters of 33–46 nm with narrow polydispersity (Dv/Dn= 1.1) and polymer content of 6–24 wt% were achieved using low levels of surfactant (dodecyltrimethylammonium bromide, DTAB) — less than 1 wt% of the reaction mixture. Particle diameter depended on polymerization temperature, MMA content, and concentrations of initiator and surfactant. Larger particles wereformed when temperature was too high, initiator concentration was too high, or surfactant concentration was too low.

Synthesis of nanosize poly(methyl methacrylate) microlatexes with high polymer content by a modified microemulsion polymerization

Polymer nanoparticles were prepared from monomers such as styrene (St), butyl methacrylate (BMA), butyl acrylate (BA), methyl methacrylate (MMA), and methyl acrylate (MA) using a modified microemulsion polymerization process. With this process high polymer: surfactant weight ratios (7 : 1 or greater), relatively concentrated (10–30 wt.-%) latexes and small (10–20 nm) particle diameters were attained. Nucleation mechanisms were investigated through observations of the particle size change during the polymerization.

High solids‐content nanosize polymer latexes made by microemulsion polymerization

Recent studies of self-condensation and co-condensation of melamine-formaldehyde resins; cure at low temperatures

A series of tung oil modified soybean alkyd emulsions are prepared by an inversion emulsified technique. In these alkyd resins, the tung oil contents are about 0, 12.5, and 25.0 wt % (based on the total oil). Using IGEPAL CO-630 as the surfactant, a very stable alkyd emulsion can be obtained. With the increase of the tung oil contents in alkyd emulsions, the initial droplet sizes of the emulsions increase dramatically. Aging under 50°C can eliminate the difference in droplet sizes; the final droplet sizes of the emulsions are about 50 nm. The alkyd resins also have good hydrolytic stability. The tung oil contents in the alkyd resins also strongly influences the film properties; suitable tung oil content improves the film gloss. An atomic force microscopy investigation shows that the film from the alkyd emulsion is more water sensitive; after a 50-h deionized water immersion, the film surface appears to have a lot of dents. This indicates that the film surface may be very rich in surfactant species. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1698–1706, 2000

Frank N. Jones

Papers

Organic Coatings : Science and Technology

Synthesis of nanosize poly(methyl methacrylate) microlatexes with high polymer content by a modified microemulsion polymerization

High solids‐content nanosize polymer latexes made by microemulsion polymerization

Recent studies of self-condensation and co-condensation of melamine-formaldehyde resins; cure at low temperatures

Stability and film properties of tung oil modified soybean alkyd emulsion