Organic Chemicals and Polymers

A few of the major classes of organic compounds and some of their reactions, especially those used in making polymers, are described in this chapter, with the goal of introducing you to a major segment of chemistry and the chemical industry. 

Carbon compounds hold the key to life on Earth. Consider what the world would be like if all carbon compounds were removed the result would be much like the barren surface of the Moon. If carbon compounds were removed from the human body, there would be nothing left except water and a small residue of minerals. The same would be true for all living things. Carbon compounds are also an integral part of our lifestyle. Fossil fuels, foods, and most drugs are made of carbon compounds. Since we live in an age of plastics and synthetic fibers, our clothes, appliances, and most other consumer goods contain a significant portion of carbon compounds. 

Over 85% of the millions of known compounds are carbon compounds, and a separate branch of chemistry, organic chemistry, is devoted to the study of them. Why are there so many organic compounds The discussion of hydrocarbons and their structural and geometric isomers in Chapter 12 indicates two reasons (1) the ability of many carbon atoms to be linked in sequence with stable carbon-carbon single, double, and triple bonds in a single molecule and (2) the occurrence of isomers. A third reason will be discussed further in this chapter the variety of functional groups that bond to carbon atoms. 

The economic importance of the organic chemical industry can be seen by looking at the list in Table 14.1 of chemicals produced in the United States in very large quantities. Four are organic chemicals. 

Sulfuric acid Burning sulfur to SO, oxidation of SO to SOj, Fertilizers, petroleum refining. 

---

Of the 20 million barrels of petroleum consumed each day in the United States, 19 million is burned for energy. The remaining 1 million is used to provide raw material for the production of organic chemicals and polymers. Thus only one-twentieth of the hydrocarbons consumed daily goes into useful materials. The rest is burned for energy and ends up as heat and smoke. 

Alkenes are not present to a significant extent in crude petroleum. They are essential starting compounds for the synthesis of organic chemicals and polymers, so their production from alkanes is of great importance. One way to produce alkenes is by cracking the petroleum by heat or with catalysts. In catalytic cracking, the heavier fractions from the distillation column (compounds of Cn or higher) are passed over a silica-alumina catalyst at temperatures of 450°C to 550°C. Reactions such as... 

Catalytic incineration (complete air oxidation) for the purification of gas streams is now quite commonly used in many applications (1-7), being preferred in these over thermal (non-catalytic) incineration and adsorption methods. It can offer advantages over thermal incineration in terms of costs, size, efficiency of destruction, and minimization of thermal NOx by-product formation. The catalytic incineration systems are now commonly employed in such applications as exhaust emission purification from a variety of industrial processes (including manufacture of organic chemicals and polymers) and air-stripping catalytic processes used to clean contaminated water or soil. 

Typically, the silicon atoms will have one or more side groups attached to them, generally phenol (CeHs—), methyl (CH3), or vinyl (CH2=CH—) units. These groups impart properties such as solvent resistance, lubricity, and reactivity with organic chemicals and polymers. Since these side groups affect the corrosion resistance of the resin, it is necessary to check with the supplier as to the properties of the resin being supplied. Table 6.10 lists the corrosion resistance of methyl appended silicone with selected corrodents. Reference 1 provides additional listing. 

Sulfolane is the most common commercially available sulfone solvent. The solvent, also known as tetrahydrothiophene-1,1-dioxide, is a colorless, highly polar liquid consisting of a fully hydrogenated five-member sulfur-carbon heterocyclic thiophene ring. The solvent is available as both anhydrous sulfolane and as sulfolane containing 3 wt% deionized water. Sulfolane is used as a reaction medium, as a solvent for a wide variety of organic chemicals and polymers, and as an extraction solvent. 

Subsequently, inorganic chemical production expanded and diversified into other areas. Anhydrite (calcium sulfate) was mined for use in sulfuric acid production, nitric acid and fertilizer production was introduced, and later organic chemicals and polymer production began, expanding to nearby Wilton. Ammonia and mineral acids are still manufactured to this day on the Billingham site. 

---