Thermoplastic and Thermosetting Polymers

As mentioned in the previous chapter, resins are polymeric materials capable of forming useful films after application of coatings. For good film formation, a high MW resin is necessary. In general, in the paint and coating industry, two types of resins are used  

These two fundamental film formation mechanisms form the basis of their classification. In general, all resins, and hence all coatings, can be classified into two distinct types, thermoplastic resins and thermosetting resins. 

Resin type Examples Film formation Applications 

Thermoplastic Thermoplastic Physical drying Acrylic coatings. 

Thermosetting resin Alkyd resins Air oxidation Architecturai enameis, primers 

Typical examples of thermosetting polymers are phenolic and urea-formaldehyde resins, unsaturated polyesters, and epoxy resins. Typical thermoplastics are polyethylene, polypropylene, polystyrene, and poly(vinyl chloride). The thermoplastic or thermosetting charaeter of a polymer 

Although a sol-gel transformation is present in the synthesis of any thermosetting polymer, in some fields it is used in a rather restrictive way. For example, ceramists associate sol-gel processes with the hydrolytic con- 

Thermosetting polymers are usually amorphous because there is no possibility of ordering portions of the network structure due to the restrictions imposed by the presence of crosslinks. Exceptions are networks obtained from rigid monomers exhibiting a nematic-isotropic transition. In these cases, a polymer network presenting a nematic-isotropic transition may be obtained, provided that the concentration of crosslinks is kept at a low value. 

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Figure 1.3 Historical discovered and production dates of commercial thermoplastic and thermoset polymers organized according to their architectural class...

Define thermoplastics and thermosetting polymers with two examples of each. 

Polymer immobilization The polymers used in the immobilization of spent materials can be classified into two main categories thermoplastic and thermosetting polymers. The first type is fed in the form of a solid, and then melts upon heating and combines with the waste. On the other hand, thermosetting polymers are supplied in a liquid form and are then polymerized to a solid form, combining with the waste upon heating or in the presence of catalysts. 

The chemistry described in this chapter is the same for the synthesis of both thermoplastic and thermosetting polymers. The transformations occurring during network formation may have a bearing either on the mechanisms (e.g., variation of the reactivity ratios along polymerization) or on the kinetics of network formation (e.g., decrease of reaction rate at the time of vitrification). These transformations and the effects they produce on the buildup of the polymer network will be discussed in the following chapters. 

So many kinds of polymers exist that scientists have developed ways of categorizing them to make it easier to study and describe them. Polymers formed by addition or condensation reactions, for example, are placed in the same category because they are formed by a common chemical reaction and, in many cases, have common physical and chemical properties. Similarly, thermoplastic and thermosetting polymers are grouped together primarily because of their behaviors when exposed to heat, and, hence, applications for which they are likely to he most suitable. 

This is a huge general category of materials, which includes both thermoplastics and thermosetting polymers. Tabular data on the corrosion resistance of these materials in a wide range of environments are available from a variety of sources. Commonly used materials of construction in the CPI include polyvinyl chloride (PVC and CPVC), polyethylene, polypropylene, polystyrene, polycarbonate, polytetrafluoroethylene (PTFE), fiberglass composite materials, and a variety of epoxies used for coatings or adhesives. 

Thermoplastic and Thermosetting Polymers. Polymer adhesives that dissolve in solvents, or that soften and flow on heating and... 

Figure 1.4 Schematic structures of thermoplastic and thermoset polymers.

Naugard . [Uniroyal Uniroyal Chem. Ltd.] Antioxidant, metal derivator, processing aid, polymerization inhibitor, stabilizer for adhesives, thermoplastic and thermoset polymers styrene inhibitors. 

Figure 1.1 Representations of thermoplastic and thermosetting polymer structures.

Several books have been devoted to the toughening of thermoplastic and thermosetting polymers [2-4]. 

Comparative Corrosion Resistance of Thermoplastic and Thermoset Polymers... 

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