P. A. T. Products

In addition to polystyrene and high-impact polystyrene there are other important styrene-based plastics. Most important of these is ABS, with a global capacity of about 5 X 10 t.p.a. and production of about 3 X 10 t.p.a. The styrenic PPO materials reviewed in Chapter 21 have capaeity and production figures about one-tenth those for ABS. Data for the more specialised styrene-acrylonitrile copolymers are difficult to obtain but consumption estimates for Western Europe in the early 1990s were a little over 60000 t.p.a. 

D. J. Wilkins and P. A. Bradley Product Glass 9 1,2,3-Thiadiazoles. in Science of Synthesis Houben-Weyl Methods of Molecular Transformations , R. C. Storr and T. L. Gilchrist, Eds. Georg Thieme Verlag, Stuttgart, 2004, vol. 13, p. 253. 

Juliet, P. A., T. Hayashi, A. Iguchi, and L. J. Ignarro. 2003. Concomitant production of nitric oxide and superoxide in human macrophages. 310... 

Parr, L. J. and Swoboda, P.A.T. The assay of conjugable oxidation products applied to lipid deterioration in stored foods. J. Food Technol. 11, 1-12 (1976). 

CgHjClaOj. M.p. 155°C. Used as a selective herbicide. It is made from 2,4,5-trichloro-pheno) and sodium chloroacetate. Ester sprays and combined ester sprays with 2,4-D are available. 2,4,5-T products are of particular value in that they control many woody species, and eradicate perennial weeds such as nettles in pastures. 

For substances with a moderate triple point pressure e.g., benzoic acid, 6 mm., m.p. 122° naphthalene, 7 mm., m.p. 80° ), the simple process described above for camphor will not give a satisfactory yield of a sublimed product. Thus, for example, if naphthalene is heated it will melt at T (80°), and will boil when the vapour pressure is 760 mm. (218°) ... 

Spectrophotometric titration curves for the titration of an analyte, A, with a titrant, T, to form a product, P, in the presence of a visual indicator. Titration curves are shown for cases where (a) only A absorbs (b) only T absorbs (c) only P absorbs (d) A and T absorb (e) P and T absorb and (f) only the visual indicator absorbs. 

A. T. Santhanam, G. P. Grab, G. A. Rolka, and P. Tierney, Proceedings of the Conference on High Temperature Productivity Machining—Materials and Processes, New Orleans, La., American Society for Metals, 1985, pp. 113—121. 

A beam of charged particles (an ion beam) with an energy from a few hundred keV to several MeV is produced in an accelerator and bombards a sample. Nuclear reactions with low-Z nuclei in the sample are induced by this ion beam. Products of these reactions (typically p, d, t, He, a particles, and y rays) are detected, producing a spectrum of particle yield versus energy. Many (p, a) reactions have energies that are too low for efficient detection. In these cases, the associated y rays are detected instead. Important examples are ... 

By the mid-1990s capacity for polyethylene production was about 50 000 000 t.p.a, much greater than for any other type of plastics material. Of this capacity about 40% was for HDPE, 36% for LDPE and about 24% for LLDPE. Since then considerable extra capacity has been or is in the course of being built but at the time of writing financial and economic problems around the world make an accurate assessment of effective capacity both difficult and academic. It is, however, appeirent that the capacity data above is not reflected in consumption of the three main types of material where usage of LLDPE is now of the same order as the other two materials. Some 75% of the HDPE and LLDPE produced is used for film applications and about 60% of HDPE for injection and blow moulding. 

As mentioned in the introduction to the chapter, world capacity to produce polyethylene was of the order of so c. 50 X 10 t.p.a. in the late 1990s although production to that level is not expected until about 2002. By type, this market is shared between LDPE, HOPE and LLDPE approximately in the ratio 40 36 24. 

In attempts to further improve the stability of fluorine-containing elastomers Du Pont developed a polymer with no C—H groups. This material is a terpolymer of tetrafluoroethylene, perfluoro(methyl vinyl ether) and, in small amounts, a cure site monomer of undisclosed composition. Marketed as Kalrez in 1975 the polymer withstands air oxidation up to 290-315°C and has an extremely low volume swell in a wide range of solvents, properties unmatched by any other commercial fluoroelastomer. This rubber is, however, very expensive, about 20 times the cost of the FKM rubbers and quoted at 1500/kg in 1990, and production is only of the order of 1 t.p.a. In 1992 Du Pont offered a material costing about 75% as much as Kalrez and marketed as Zalak. Structurally, it differs mainly from Kalrez in the choice of cure-site monomer. 

Production of SMA materials is of the order of 25 000 t.p.a. and recent reports refer to an annual growth rate of the order of 10-15%. 

By the mid-1990s world production of aminoplastics was estimated at about 6 000 000 t.p.a. of which more than 5 000 000 t.p.a. were urea-formaldehyde resins. The bulk of the rest were melamine-formaldehyde. Such bald statistics, however, disguise the fact that a considerable amount of aminoplastics used are actually co-condensates of urea, melamine and formaldehyde. 

In 1997 it was estimated that global production of PET was about 16.7 X 10 t.p.a., of which 12 million tonnes was used in textiles, 2 million tonnes for audio and video film (with a small quantity for technical mouldings) and 3 million tonnes for packaging, particularly bottles. The tremendous growth in the bottles market from zero in the late 1970s to 1.5 million tonnes in the USA alone in 1998 is, in consumption terms, one of the most spectacular examples of growth in plastics materials in recent times and will be considered later in this section. 

Although first marketed by Zeneca, a company split off from ICI in 1993, under the trade name of Biopol, marketing was transferred to Monsanto in May 1996. In 1993 production capacity was 600t.p.a. but prior to the Monsanto takeover had been expected to rise to 5000-10 000 t.p.a. by the late 1990s. However, in November 1998 Monsanto announced that it was discontinuing the Biopol programme. 

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