The Polymer Industry

The polymer industry is also adopting more sustainable practices. The polycarbonate (PC) Lexan is used in cars, appliances, CDs, and DVDs (Fukuoka et al., 2003). The polymer is termed an engineer- 

FIGURE 9.19. Synthesis of bisnoraldehyde from soya sterols. 

FIGURE 9.20. Biocatalytic production of acrylamide Mitsubishi process. 

Mitsubishi Rayon produces acrylamide from acrylonitrile with the help of an immobilized bacterial enzyme, nitrile hydratase (see Fig. 9.20). This acrylamide is then polymerized to the conventional plastic polyacrylamide. This process was one of the first large-scale applications of enzymes in the bulk chemical industry and replaced the conventional process that used sulfuric acid and inorganic catalysts. The enzymatic process has several advantages over the chemical process. The efficiency of the enzymatic process is 100%, while that of the previous chemical process was only 30-45%. The energy consumption is only 0.4MJ/kg product, compared to 1.9MJ/kg product for the chemical route. The process generates less waste. The CO2 production is only 0.3 kg/kg monomer, while the previous process produced 1.5 kg/kg. The reaction is carried out at 15°C, which is milder than the original chemical route. About 100,000 tons of acrylamide are produced yearly now via this approach in Japan and other countries. 

Baxenden Chemicals Ltd. (UK) has developed a large scale lipase-catalyzed process for the production of poly (hexane-1,6-diol adipate). The process consists of condensation of hexane-1,6-diol and adipic acid using Candida antaictica lipase. Constant removal of water from the enzyme-catalyzed polymerization process is crucial to shift the equilibrium to the right. This simple lipase-catalyzed polyester manufacture is operated at ambient temperature and does not require a solvent. In addition, the process is very economical when compared to the chemical process. 

---

Uses. Butanediol is used to manufacture the insecticide Endosulfan, other agricultural chemicals, and pyridoxine (vitamin B ) (see Vitamins) (116). Small amounts are consumed as a diol by the polymer industry. 

Radicals are employed widely in the polymer industry, where their chain-propagating behavior transforms vinyl monomers into polymers and copolymers. The mechanism of addition polymeri2ation involves all three types of reactions discussed above, ie, initiation, propagation by addition to carbon—carbon double bonds, and termination ... 

Organic peroxides are used in the polymer industry as thermal sources of free radicals. They are used primarily to initiate the polymerisation and copolymerisation of vinyl and diene monomers, eg, ethylene, vinyl chloride, styrene, acryUc acid and esters, methacrylic acid and esters, vinyl acetate, acrylonitrile, and butadiene (see Initiators). They ate also used to cute or cross-link resins, eg, unsaturated polyester—styrene blends, thermoplastics such as polyethylene, elastomers such as ethylene—propylene copolymers and terpolymers and ethylene—vinyl acetate copolymer, and mbbets such as siUcone mbbet and styrene-butadiene mbbet. 

Etee-tadical reactions ate accompHshed using a variety of processes with different temperature requirements, eg, vinyl monomer polymerization and polymer modifications such as curing, cross-linking, and vis-breaking. Thus, the polymer industries ate offered many different, commercial, organic peroxides representing a broad range of decomposition temperatures, as shown in Table 17 (19,22,31). 

Nuclear Magnetic Resonance (nmr). The nmr analysis has been used in the polymer industry for some time to measure properties such as amount and type of branching, polymerized ethylene oxide content, and hydroxyl content. The same techniques are applicable to waxes, and are used for both characterization and quality control. 

Mention should be made of the nomenclature for the polymer. Industrially the materially is invariably known in the English-speaking world as polypropylene. However, the lUPAC name for the monomer is propene and until 1975 the recommended lUPAC name was polypropene, a term very rarely used. The latest lUPAC rules base the name of a polymer on the constitutional repeating unit, which in this case is a propylene unit (c.f. a methylene unit for polyethylene) and this leads to the name poly(propylene) (i.e. with brackets). In this volume the more common, unbracketed but still unambiguous name will be used. 

Another example in the polymers industry is illustrated in Figure 17, which is a process aimed at the batch drying of waste residue with solvent recovery. In this application liquid or viscous waste solutions are pumped into a batch dryer where they are dried under vacuum to a solid granular residue. Vaporized water and solvent are recovered by condensation and then separated by gravity. The process scheme is flexible, offering a range of temperatures and vacuum levels for treating... 

The plastics industry was launched nearly 150 years ago with the production of certain derivatives of cellulose. However, its real emergence as a growth industry of immense proportions and importance has occurred since World War II with the sustained strong growth of thermoplastics and specialty elastomers. The importance of the polymers industry in modern society is underscored by the myriad of uses already developed for these materials, with more being developed almost daily. Although there are a multitude of polymers that are derived from hydrocarbons, we will only briefly discuss the more common thermoplastics that are made from relatively simple monomers from petroleum. 

Free radical polymerization is a key method used by the polymer industry to produce a wide range of polymers [37]. It is used for the addition polymerization of vinyl monomers including styrene, vinyl acetate, tetrafluoroethylene, methacrylates, acrylates, (meth)acrylonitrile, (meth)acrylamides, etc. in bulk, solution, and aqueous processes. The chemistry is easy to exploit and is tolerant to many functional groups and impurities. 

UV absorbers have been found to be quite effective for stabilization of polymers and are very much in demand. They function by the absorption and harmless dissipation of the sunlight or UV-rich artificial radiation, which would have otherwise initiated degradation of a polymer material. Meyer and Geurhart reported, for the first time in 1945 [10], the use of UV absorber in a polymer. They found that the outdoor life of cellulose acetate film was greatly prolonged by adding phenyl salicylate (salol) [10]. After that, resorcinol monobenzoate, a much more effective absorber, was introduced in 1951 [11] for stabilization of PP, but salol continued to be the only important commercial stabilizer for several years. The 2,4-dihydroxybenzophenone was marketed in 1953, followed shortly by 2-hydroxy-4-methoxybenzophenone and other derivatives. Of the more commonly known UV absorbers, the 2-hydroxybenzophenones, 2-hy-droxy-phenyl-triazines, derivatives of phenol salicylates, its metal chelates, and hindered amine light stabilizers (HALS) are widely used in the polymer industry. 

Vinyl chloride is a reactive gas soluble in alcohol hut slightly soluble in water. It is the most important vinyl monomer in the polymer industry. The U.S. production of vinyl chloride, the 16th highest-volume chemical, was approximately 14.8 billion pounds in 1994. 

Supply is related to cost. If basic materials become scarce, changes will follow. Thus constraints in the petroleum supply may affect the polymer industry, which is based almost entirely on petrochemicals. We can look for expanded use of paper-based materials to provide factors such as bulk, tensile properties, and thermal resistance combined with the low weights of proper barrier materials. Composites will continue to grow in quantity and complexity. 

A most important class of pump for dealing with highly viscous material is represented by the screw extruder used in the polymer industry. Extruders find their main application in the manufacture of simple and complex sections (rods, tubes, headings, curtain rails, rainwater gutterings and a multitude of other shapes). However, the shape of section produced in a given material is dependent only on the profile of the hole through which the fluid is pushed just before it cools and solidifies. The screw pump is of more general application and will be considered first. 

Although, the enzymatic reaction of esters with amines or ammonia have been well documented, the corresponding aminolysis with carboxylic acids are rarer, because of the tendency of the reactants to form unreactive salts. For this reason some different strategies have been used to avoid this problem. Normally, this reaction has been used for the preparation of amides of industrial interest, for instance, one of the most important amides used in the polymer industry like oleamide has been produced by enzymatic amidation of oleic acid with ammonia and CALB in different organic solvents [10]. 

The preferred term throughout this book is relative molar mass, but we should note that the use of this term is not common in polymer chenfistry. More often the older term molecular weight is used, both throughout the polymer industry and among acadenfic polymer scientists. This usage extends even to the current research literature. 

Small versions of production facilities are sometimes used for product development, particularly in the polymer industries. Single-train plants producing... 

Report 3 Advanced Composites, D.K. Thomas, RAE, Famborough. Report 4 Liquid Crystal Polymers, M.K. Cox, ICI, Wilton. Report 5 CAD/CAM in the Polymer Industry, N.W. Sandland and M.J. Sebbom, Cambridge Applied Technology. Report 8 Engineering Thermoplastics, I.T. Barrie, Consultant. Report 11 Communications Apphcations of Polymers,... 

In the polymer industry, post-reaction product treatment processes such as liquid-solid separation, drying, precipitation, particle size control, and polymer purification are very complex and costly. Future polymer plants should be designed such that process equipment can be easily and quickly converted to making new products at minimal cost and with... 

Nylon 66 was the first polyamide to be produced commercially. Developed by Wallace Carothers at the DuPont Chemical Company In 1935, it still leads the polymer industry in annual production. Figure 13-7 illustrates that Nylon 66, made from adipic acid and hexamethylenediamine, is so easy to make that it is often used for a classroom demonstration ... 

Although most industrial catalysts are heterogeneous, a growing number of industrial reactions use homogeneous catalysts. One example is the production of acetic acid. Most of the 2.1 billion kilograms of acetic acid produced annually is used in the polymer industry. The reaction of methanol and carbon monoxide to form acetic acid is catalyzed by a rhodium compound that dissolves in methanol ... 

CH2 CH3. Organoaluminum compounds, including triethylaluminum, are used to make catalysts for the polymer industry. 

These results clearly show that these novel catalysts exhibit low metathesis activity at the studied temperatures and therefore can operate as dormant catalysts. This behavior is very important in the polymer industry. 

NMR microscopy is ultimately an innovative method of research and it is not surprising that most of the commercially installed systems, approximately 80%, are installed in public scientific research centers, where new applications are continuously being developed. The method is not particularly widely distributed in industry, where standardized methods are more often used. However, NMR microscopy is mainly used in the pharmaceutical industry for the development of new drugs, in the food industry for the development of new types of food, in the chemical industry for creating and characterizing new materials and in the polymer industry, e.g., for creating new mixtures for tires. 

Anderson [90] foresees a bright future for SFE-pSFC, with applications in the polymer industry. However, it does not appear that routine SFE-SFC quantitation is an easy matter. SFE, SFC and SFE-SFC applications have been described in various reviews and books (Sections 3.4.2, 4.3 and Bibliography). 

Also, polymer additives in medical plastics have been analysed by means of GC-MS [293]. 4,4 -Methyl-enebis(2-chloroaniline) (MBOAC), used in the polymer industry to cure urethane elastomers and epoxy resins, has been analysed in body fluids by means of GC-MS [294]. GC-MS has also been used to examine extracted PP/Triclosan (sanitiser) [243]. 

Although the polymer industry is often considered a bulk industry, the development and production of the different types, grades and compounds requires advanced technology and an appreciable amount of R D. In support of the industrial development phase, production control and quality management, the polymer industry needs to determine more than 60 elements in polymeric materials, in concentrations ranging from per cent down to ppt levels. 

---