History epoxy resin

The history of epoxy resins begins in the early 1900s with the reported epoxidation of olefins. This technique was used only for the production of higher molecular weight mono-epoxy compounds. The technology was further explored only after the Second World War. Different contributions in the development of epoxies are outlined as follows (Lee and Nivelle, 1967, 1972 Sherman et al, 1982). 

Chlorinated benzenes are key precursors for the industrial production of colours, pesticides, rubber products and disinfectants. Additionally, hexachlorobenzene (HCB) was used for a long time as a pesticide. Octachlorostyrene is a specific by-product of the production of magnesium, as well as a by-product of the technical production of chlorine (Kaminski and Hites, 1984). Hexachloro-1,3-butadiene is used in the rubber production, as hydraulic liquid, solvent and as a by-product of the technical synthesis of chlorinated compounds like tetrachloroethene (Booker and Pavlostathis, 2000). Bis(chloropropyl)ethers represent byproducts of the technical synthesis of epichlorhydrin, used for the production of epoxy resins and disinfectants. The concentration profile of the individual chlorinated compounds reveals different emission histories. 

Tensile tests were performed on neat epoxy resins In the following conditions as-cast, as-postcured, as-quenched, and aged at decade Increments from 10 to 10 minutes at 140°C In nitrogen while stored In darkness. A summary of the observed resin stress-strain behavior Is shown In Figure 2. As can be seen, the epoxy polymer was found to be extremely sensitive to thermal history. 

The objective of this section is to characterize the thermal stability of uncured solid rubber-modified epoxy resins. The effects of extended thermal history on melt viscosity and epoxide equivalent weight are discussed. The influence of the type and concentration of CTBN elastomer in the solid rubber-modified epoxy resin on melt viscosity and EEW is also discussed. Mechanistic considerations are proposed to explain the side reactions which influence the thermal stability of solid rubber-modified epoxy resins. 

The successful scale-up of advancement and modification of rubber-modified epoxy resins is discussed. Mechanisms are proposed for both advancement and esterification reactions as catalyzed by triphenylphosphine which are consistent with experimental results. A plausible mechanism for the destruction of the catalyst is also presented. The morphology of these materials is determined to be core-shell structures, dependent upon composition and reaction and processing conditions. Model studies have been performed to determine the effects of thermal history on the kinetics of reaction. These efforts have resulted in the successful scale-up and use of rubber-modified epoxy resins as functional coatings in the electronics industry. 

Figure 11. Thermal expansion behavior of Fiberite 954 epoxy resins as a function of thermal history.

FIGURE 2 Specific volume and temperature history of the lOOlF/DDS epoxy resin during curing under a pressure of 5 MPa. 

FIGURE 12.13 (a) Specific voiume - temperature history of 1001F/DDS epoxy resin during curing under a pressure of 5 MPa. (b) Specific voiume data from Fig. 12.13a piotted as a function of the temperature. 

History. The Shell Chemical Corporation introduced the epoxy resin systems into the United States in 1941, and their good property profile has been utilized in a wide range of applications. The molding compounds are available in extreme soft flows and long gelation times, which make them very adaptable for encapsulation molding techniques in the encapsulation of electronic components such as integrated circuits, resistors, diode capacitors, relays, and bobbins. 

Humans who had a history of allergic to test allergens Epoxy resin, glyceryl monothioglycolate, frullania, and tansy One BC Minimizing the development of allergic contact dermatitis McClain and Storrs [62]... 

Holness and Nethercott (1993) found 18% of patients with a history of potential exposure to the epoxy-resin... 

Mackie RM (1987) Links between exposure to ultraviolet radiation and skin cancer. J R Coll Physicians Lond 21 91 Maitra RS, Johnson DL (1997) Stress fractures clinical history and physical examination. Clin Sports Med 16 259-274 Malanin G, Kalimo K (1985) Facial dermatitis from epoxy resin in a helmet. Contact Dermatitis 12 220-237... 

Table 1. History of U.S. Epoxy Resin Annuai Production ...

Lewis, A.F. Doyle, M.J. Gillham, J.K. Effect of cure history on dynamic mechanical properties of an epoxy-resin. Polym. Eng. Sci. 1979, 19, 683-686. 

Epoxy resins also can look back at a long history of development, as the first ones became commercial in the early 1940s after their invention in 1938. The term... 

The influence of residual solvent and that of thermal history during curing on the mechanical properties of diglycidyl ether of bisphenol A cured with dia-minodiphenyl methane epoxy resins can be summarized as follows [138] ... 

Vinyl ester resins (VERs, epoxy methacrylates) are a major class of styrenated, free radically curable, corrosion- and chemical-resistant thermoset resins. They are largely used in fiber-reinforced structural applications, and they have a substantial history of long-term service in numerous environments at elevated temperatures and pressures, usually under load. 

This chapter will deal with the chemistry and applications of epoxies, phenolics, urethanes, and a variety of current vogue high-temperature polymers. Applications in fiber-reinforced plastics will be discussed in the individual sections on resin chemistry where appropriate. Separate sections will deal with adhesives and sealants. Adhesives are most important because, as early history demonstrates, they led the way to the application of resins in aerospace. A section is also included on silicone and polysulfide sealants. Although these materials are elastomers rather than resins, no discussion of aerospace polymers would be complete without some mention. Some major thermosetting polymers have been omitted from this review. Among these are the unsaturated polyesters, melamines, ureas, and the vinyl esters. Although these products do find their way into aerospace applications, the uses are so small that a detailed discussion is not warranted. 

In all the history of the coatings and plastics industries, more especially, since synthetically prepared raw materials have taken their principal position in the technology, there has not appeared a resin which has lent itself to so wide a variety of uses, to 30 wide a variety of applications, and which has been shown to have such a wide field of technical and economic utility, as does epoxy. 

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