Polyvinyl process technologies

Following the war, Solvay expanded its output in its European factories and built new ones in Italy, Greece, and other countries. It maintained ties with all its earlier allies except, of course, with Russia, where its properties had been confiscated. Before World War I, however, it had done little to commercialize new chemicals through process technologies, as Dow had done in the United States. But it did move into polymer/petrochemicals quickly after World War II. In 1949 Solvay initiated the production of polyvinyl chloride, becoming a European leader in that basic polymer commodity. The company then entered into the production of HDPB in 1959 and PP in 1966. Shortly thereafter, it began to produce a variety of end-products in the manner of the American companies for use in both consumer and industrial chemical lines. In 1974 Solvay returned to the U.S. markets, setting up headquarters in Deer Park, Texas. By that time its soda ash and caustic soda processes had become obsolete.3 ... 

In this chapter, the big four thermoplastics are covered polyethylene, polypropylene, polyvinyl chloride, and polystyrene. Like most other thermoplastics, they are long-chain polymers that become soft when heated and can be molded under pressure. They are linear- or branch-chained and, except for some exotic copolymers, have little or no cross-linking. Technological advances continue. Research in copolymerization, catalysts, processing, blending, and fabricating continues even as you read this. 

Morrow makes a point of calling the system designed at CPRR a "resin recovery system, to stress the fact that it will work on about five different resins. Currently PET and HDPE can be processed together and are easily separated because of their different densities. The center hopes to add polystyrene and polyvinyl chloride to the mixed plastics stream they process. But, with the present technology, PET and PVC cannot be run together since they have similar densities. 

Chlorine (from the Greek chloros for yellow-green ) is the most abundant halogen (0.19 w% of the earth s crust) and plays a key role in chemical processes. The chlor-alkali industry has been in operation since the 1890s and improvements in the technology are still important and noticeable, for example, the transition from the mercury-based technology to membrane cells [60]. Most chlorine produced today is used for the manufacture of polyvinyl chloride, chloroprene, chlorinated hydrocarbons, propylene oxide, in the pulp and paper industry, in water treatment, and in disinfection processes [61]. A summary of typical redox states of chlorine, standard potentials for acidic aqueous media, and applications is given in Scheme 2. 

Vinyl chloride monomer (VCM) is one of the leading chemicals used mainly for manufacturing polyvinyl chloride (PVC). The PVC worldwide production capacity in 2005 was of about 35 million tons per year, with an annual growth of about 3%, placed after polyolefines but before styrene polymers. In the 1990s the largest plant in the USA had a capacity of about 635 ktons [1], but today there are several plants over one million tons. At this scale even incremental improvements in technology have a significant economic impact. Computer simulation, process optimization and advanced computer-control techniques play a determinant role. 

Besides the "immobilized" CF3SO3H, another homogeneous catalyst is anionic [Rh(00)212]. This was the first active rhodium catalyst for the carbonylation of methanol to acetic acid. Recently, Chiyoda and UOP introduced the Acetica process, a novel technology based on an "immobilized" [Rh(CO)2l2] on a polyvinyl pyridine resin. Compared with the existing homogeneous process, immobilization increases catalyst concentration in the reaction mixture. 

Vinyl acetate was first described in a German patent awarded to Fritz Klatte and assigned to Chemishe Fabriken Grieshiem-EIectron in 1912. It was identified as a minor by-product of the reaction of acetic acid and acetylene to produce ethylidene diacetate. By 1925, commercial interest in vinyl acetate monomer and the polymer, polyvinyl acetate, developed and processes for their production on an industrial scale were devised. The first commercial process for vinyl acetate monomer involved the addition of acetic acid to acetylene in the vapor phase using a zinc acetate catalyst supported on activated carbon. This process was developed by Wacker Chemie in the early 1930s and dominated the production of vinyl acetate until the 1960s when an ethylene-based process was commercialized which supplanted the earlier acetylene technology [24]. 

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