Chapter Twelve: Synthetic Petroleum-Based Polymers
The synthetic polymer industry represents the major end use of many petrochemical monomers such as ethylene, styrene, and vinyl chloride. Synthetic polymers have greatly affected our lifestyle. Many articles that were previously made from naturally occurring materials such as wood, cotton, wool, iron, aluminum, and glass are being replaced or partially substituted by synthetic polymers. Clothes made from polyester, nylon, and acrylic fibers or their blends with natural fibers currently dominate the apparel market. Plastics are replacing many articles previously made of iron, wood, porcelain, or paper in thousands of diversified applications. Polymerization could now be tailored to synthesize materials stronger than steel.1 For example, polyethylene fibers with a molecular weight of one million can be treated to be 10 times stronger than steel! However, its melting point is 148 C. A recently announced thermotropic liquid crystal polymer based on p-hydroxybenzoic acid, terephthalic acid, and p, p'-biphenol has a high melting point of 420 C and does not decompose up to 560 C. This polymer has an initial stress of 3.4 10 6 kg/mm 2, even after 6,000 hours of testing.2
The polymer field is versatile and fast growing, and many new polymers are continually being produced or improved. The basic chemistry principles involved in polymer synthesis have not changed much since the beginning of polymer production. Major changes in the last 70 years have occurred in the catalyst field and in process development. These improvements have a great impact on the economy. In the elastomer field, for example,...