Polymers Coatings

Technology and Applications

Rajender Boddula, Mohd Imran Ahamed, Abdullah M. Asiri

• Publisher: Wiley-Scrivener
• Year: 2020
• Print ISBN: 9781119654995
• eBook ISBN: 9781119655176
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

The explores the cutting-edge technology of polymer coatings. It discusses fundamentals, fabrication strategies, characterization techniques, and allied applications in fields such as corrosion, food, pharmaceutical, biomedical systems and electronics. It also discusses a few new innovative self-healing, antimicrobial and superhydrophobic polymer coatings. Current industrial applications and possible potential activities are also discussed.

1
Fabrication Methods for Polymer Coatings

Hüsnügül Yilmaz Atay

İzmir Katip Çelebi University, Department of Material Science and Engineering, Çiğli İzmir, Turkey

Abstract
Polymer coatings mean the top layer applied on any substance for purposes like protection and decoration. It is possible to apply to synthetic materials as well as metals and ceramics. They are resistant to high temperatures, such as up to about 280°C. The polymeric coating process comprises applying a polymeric material onto a supporting substrate and coating the substrate surface. Polymeric coatings can be obtained using natural and synthetic rubber, urethane, polyvinyl chloride, acrylic, epoxy, silicone, phenolic resins or nitrocellulose, etc. There are a wide range of fabrication methods to design and construct polymer-coated materials. In this chapter, the techniques are described and discussed including blade coating, spray coating, thermal spray coating, pulsed laser deposition, plasma polymerization, flow coating, spin coating, sol–gel, dip coating, and grafting. The key point is provided to highlight current methods and recent advances in polymer coating fabrication techniques.

Keywords: Polymer coatings, fabrication methods, blade coating, spray coating, thermal spray coating, pulsed laser deposition, plasma polymerization, flow coating, spin coating, sol–gel, dip coating, and grafting

1.1 Introduction

Polymer coatings are thin polymer films that are applied to flat surfaces or irregular objectives. Protective and decorative layers can be served by these coatings [1]. They can be functional coatings such as adhesives or photographic films. They can be used as corrosion inhibitors or for decorative purposes like paints. Moreover, for modifying the surfaces, they can be utilized such as paper coatings or hydrophobic coatings.

Polymeric coatings are known to be made of organic materials. However, they may contain metallic or ceramic grains to enhance endurance, property, or appearance [2]. They offer various properties and additional benefits, for instance, very good chemical resistance, very good blocking resistance, and excellent scratch and abrasion resistance. Besides, high gloss to matt looks, soft touch effect, noncoloring after UV exposure, excellent adhesion on metal and plastics, short drying time, fast hardness development, and easy formulation are other acquirements of those coatings [3].

In general, polymer coatings are architected to manufacture a film of a kind of polymer. The process should be as fast as possible. The thickness is typically 1–100 m. The type of coating method varies according to the thickness of the desired covering, the rheology of the running, and the velocity of the web [2].

1.1.1 Starting Liquid Types

Before passing through to the coating methods, it is better to explain starting liquid types to obtain an impermeable and indiscrete polymer coating deposit. Three different types of starting liquids can be used to achieve this output. These are indicated as: polymer solutions, monomer liquids, and polymer latexes [2].

1.1.1.1 Polymer Solutions

It is necessary to decrease the viscosity of the polymer to make it a stickable fluid. For this purpose, the polymer is decomposed in a dissolvent. The fluidity property of the solution is regulated by varying the amount of solvent in the solution. The resulting fluid is covered onto the substrate. The dissolvent should then be removed by a drying operation. The glass transition temperature of the dispersion rises with removal of the solvent. If the drying temperature is smaller than the glass transition temperature, the coating passes to the solid phase. However, when the drying temperature is higher than room temperature, it is seen that solidification or hardening continues during the cooling of the coating. On the other hand, some of the polymers can crystallize when the dissolvent is removed. While some are cooling, they form semi-crystalline final polymer coatings [2].

Generally, most polymers are insoluble in water and organic solvents are used for dissolution. The solvent is selected in terms of both its ability to dissolve the polymer and its influence on the drying step. Due to the need to add different additives and reduce the cost, it may be necessary to use more than one volatile solvent [2].

The use of coatings produced with polymer solution is favored as they can be applied to a wide variety of polymers at the processing site specifications and formulated according to adjustable properties to produce evaluated properties in the last product. The quantity of polymeric material soluble in a solvent is relatively small. The drying requirement therefore appears as a function of the unit thickness of the coating. On the other hand, there are environmental and safety concerns due to complications related to solvent use. Solvent recycling is another important problem. It is also another disadvantage that flammable solvents need to be captured by expensive driers [2].

1.1.1.2 Liquid Monomers

Many monomers have fluid properties at room temperature. Therefore, there is no need to decrease their flow resistance at the coating process temperature. Also, they can be covered directly without adding any dissolvent. Oligomeric precursors can be said to be in this category. Without the need for a drying operation, the monomer liquids are allowed to solidify by serial curing reactions. Meanwhile, the molecular weight of the covering material rises in the period from progression of curing to the formation of a solid polymer layer. Hardening reactions are initiated by exposing them to energetic sources, for instance, ultraviolet light or electron beams [2].

The most widely used and popular coating material is epoxy in the field. They are not monomers, yet they are formed by a chemical reaction of oligomeric resins with its hardeners. The liquids can also be produced with dissolvent to enhance interoperability. Acrylates as liquid monomers are widely used for ultraviolet curing [2].

Monomer fluids do not require much drying step because they contain very little solvent. Therefore, they are quite attractive ways for coatings. The final coating properties (e.g., density of crosslinking) can be managed at the curing stage using parameters such as temperature, ultraviolet density, or the resin chemistry. Nevertheless, in some cases, the materials used in functional polymer solution coatings may be less expensive than monomers and initiating agents. Besides, due to the high degree of crosslinking, the final product can sometimes be brittle [2].

1.1.1.3 Polymer Latex

A latex can be defined as the dissipation of polymeric grains in water. In the case of lower water solubility of the polymeric materials having functional properties, the latex paths supply an environmentally suitable solution for forming enduring covering. Grains varying in size from ~ 10 nm to 1 umm can be ...

Table of contents

• Cover
• Table of Contents
• Preface
• 1 Fabrication Methods for Polymer Coatings
• 2 Fabrication Methods of Organic/Inorganic Nanocomposite Coatings
• 3 Dry Powder Coating Techniques and Role of Force Controlling Agents in Aerosol
• 4 Superhydrophobic Polymer Coatings
• 5 Superhydrophobic Coatings Applications
• 6 Adsorptive Polymer Coatings
• 7 Polyurethane Coatings
• 8 Electroactive Polymer Nanocomposite Coating
• 9 Conducting Polymer Coatings for Corrosion Resistance in Electronic Materials
• 10 Polymer Coatings for Food Applications
• 11 Biopolymers as Edible Coating for Food: Recent Trends
• 12 Polymer Coatings for Pharmaceutical Applications
• 13 Self-Healing Polymer Coatings
• 14 Polymer Coatings for Biomedical Applications
• 15 Antimicrobial Polymer Coating
• 16 Characterization Techniques for Polymer Coatings
• 17 Polymer Coatings for Corrosive Protection
• 18 Polymer Coating for Industrial Applications
• 19 Formulations for Polymer Coatings
• Index
• End User License Agreement