Other developments

Another application of compatibilisers is in intumescent formulations for PP compositions used in vehicles, where better flame retardancy is being sought for various reasons. The intumescent mixtiue sometimes incorporates a polyamide as the carbonisation polymer, together with ammonium polyphosphate (APP) to improve the fire performance. PA and APP have limited compatibility, and EVA can overcome this. Attempts have been made to demonstrate that such mixtmes can count towards the 80% of recyclable vehicle weight demanded by the EU Directive relating to end-of-vehicle life issues. 

There has been growing demand for nonhalogen, low smoke polymers for wire and cable insulation and sheathing. These products can be polyolefins with nonhalogen flame retardants, often metal hydroxides. DuPont markets a maleated compatibiliser under the name Fusabond to compatibilise polyolefins with the inorganic flame retardants, ATH and magnesium hydroxide, as well as with mineral fillers like calcium carbonate. 

At a time when every effort is being made to increase productivity and reduce cycle times, filled plastics can increase throughput rates by virtue of their faster cooling rates. Fillers that do not slow down processing in other ways - by producing excessively high viscosity mixes or introducing dispersion difficulties - are preferred. 

Demand for mineral fillers arises chiefly from the desire for cheap thermoplastics to be given better resistance to distortion under load, especially at elevated temperatures. This need is particularly great in automotive applications. The stiffening effect of the filler also allows thinner sections, using fine particle sizes. 

It is estimated that about one and a half million tonnes of filler undergoes smface treatment with a coupling agent to improve bonding to plastics. Some are coated for a different reason, i.e., to improve dispersion. 

Technological, environmental and dietary developments do have a profound impact on per capita consumption in many countries. An increased diversion of oils and fats for oleochemicals and feed and the tendency of nutritionists to urge people to consume less fat will of course have a negative influence on per capita consumption globally. Even though there has been some influence on per capita consumption for food in developed countries, where it is already too high, this has been balanced by a sharp increase in per capita consumption for non-food uses. Thus per capita consumption will continue to rise for 10-15 years, although probably at a lower rate than in the past 15 years. 

New glass fibre-reinforcement products for u.se in fibre-directed preform processes are another focus of development, designed specifically for liquid composite moulding applications such as resin transfer moulding with thermoset polyesters. 

A new E-glass roving gives fast wet-out with polyester, vinyl ester, epoxy, phenolic, urethane, and furan resin systems, due to low sizing content. Low loss on ignition means that there is not an excessive amount of sizing to be broken down by the styrene in the resin. 

Owens Coming s Miraflex fibre is two different forms of glass fibre fused together in a single filament, resisting typical textile processes such as carding and needling the fibres are random twisted, flexible,. soft-touch, and virtually itch free. 

Also working on mixtures, Vetrotex CertainTeed has developed Twintex - a commingled reinforcement of unidirectional glass fibre rovings and polypropylene filaments. 

PPG Industries has introduced MatVantage - a continuous strand mat for pultrusion, offering unique laminate characteristics - and new low-catenary conventional rovings plus three new chopped strands for thermoplastics. Type 2016 roving is for direct-draw filament winding for oilfield composite pipe and 

Well-controlled polymerization of substituted acetylenes was also reported. A tetracoordinate organorhodium complex induces the stereospecific living polymerization of phenylacetylene.600 The polymerization proceeds via a 2-1 -insertion mechanism to provide stereoregular poly(phenylacetylene) with m-transoidal backbone structure. Rh complexes were also used in the same process in supercritical C02601 and in the polymerization of terminal alkyl- and arylacetylenes.602 Single-component transition-metal catalysts based on Ni acetylides603 and Pd acet-ylides604 were used in the polymerization of p-diethynylbenzene. 

IUPAC Commission on Macromolecular Nomenclature, Pure Appl. Chem. 40, 479 (1974). 

Pepper, in Friedel-Crafts and Related Reactions, Vol. 2, G. A. Olah, ed., Wiley-Interscience, New York, 1964, Chapter 30, p. 1293. 

The Chemistry of Catalytic Hydrocarbon Conversions, Academic Press, New York, 1981, 1981, Chapter 1, p. 32. 

Kustov, V. Yu. Borovkov, and V. B. Kazansky, in Structure and Reactivity of Modified Zeolites, Studies in Surface Science and Catalysis, Vol. 18, P. A. Jacobs, N. I. Jaeger, P. Jifu, V. B. Kazansky, and G. Schulz-Ekloff, eds., Elsevier, Amsterdam, 1984, p. 241. 

Propene gives acetone and a small amount of propionaldehyde on oxidation under Wacker conditions, that is, in the presence of PdCl2 and CuClj. A commercial process has been developed by Hoechst AG, and two plants have been erected in Japan. The process is carried out by the two-stage technology. A regeneration step is also used to decompose copper oxalate thermally. Propionaldehyde is removed by distillation together with the light ends and isolated by a separate distillation step [37, 38]. 

Butene-1 and butene-2 give methyl ethyl ketone (butanone) on oxidation with PdCl2 and CuClj. But here, a particularly high amount of chlorinated butanone, that is, 3-chlorobutanone-2, is formed. Although this product proved to be a valuable starting material for organic syntheses, the process did not gain industrial interest. Wacker ran a pilot plant [38]. 

Wacker oxidation of the lower olefins follows the same rate law as that of ethylene (Eq. (9.29) [15, 32], compare Eq. (9.5))  

The rates decrease in the order ethylene propene 1-butene cis-2-butene ra s-2-butene. 

The Wacker process, the oxidation of ethylene to acetaldehyde, lost its original importance over the past 30 years. While at the beginning more than 40 factories with a total capacity of more than 2 million tons of acetaldehyde per year were installed, acetaldehyde as an industrial intermediate was replaced successively by other processes. For example, compounds such as butyraldehyde/butanol are produced by the oxo process from propylene, and acetic acid by the Monsanto process from methanol and CO or by direct oxidation of ethane. The way via acetaldehyde to these products is dependent on the price of ethylene. Petrochemical ethylene from cracking processes became considerably more expensive during these years. Thus, only few factories would be necessary to meet the demand for other derivatives of acetaldehyde such as alkyl amines, pyridines, glyoxal, and pentaerythritol. 

Before catalytic tests, the flux of CO2 and 1-butene through the membrane were measured at operating temperature and pressure to ensrue that satisfactory reaction conditions were established. It is important in such systems that the pressure on the product side of the membrane remains high enough to transport the products and any imreacted starting materials into the collection vessel at a reasonable rate. 

McHugh, V. J. Keukonis, Supercritical Fluid Extraction Principles and Practice, 2nd ed., Butterworth-Heinemann, Oxford 1994. 

Iverson, T. Iaesen, O. Heneiksen, K. Felsvang, in Proceedings of 6th International Symposium on Supercritical Fluids, Versailles, France 2003. 

Cole-Hamilton,/. Chem. Soc. Dalton Trans. 2002, 4569 (b) M. F. Sellin, 

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A lively and optimistic survey of a new breed of businessmen who are breaking away from huge companies to form dynamic enterprises in microelectronics, biotechnology and other developing areas. 

Not surprisingly, costs are several times higher than conventional wells. Nevertheless, overall project economics may favour ERD over other development options. For example, BP developed the offshore part of the Wytch Farm Oilfield (which is located under Poole Harbour in Dorset, UK) from an onshore location. The wells targeted the reservoir at a vertical depth of 1,500 meters with a lateral displacement of over 8,000 meters (Fig. 3.20). The alternative was to build a drilling location on an artificial island in Poole Bay. ERD probably saved a considerable amount of money and advanced first oil by several years. 

This produces a double layer of charge, one localized on the surface of the plane and the other developed in a diffuse region extending into solution. 

For the Berry phase, we shall quote a definition given in [164] ""The phase that can be acquired by a state moving adiabatically (slowly) around a closed path in the parameter space of the system. There is a further, somewhat more general phase, that appears in any cyclic motion, not necessarily slow in the Hilbert space, which is the Aharonov-Anandan phase [10]. Other developments and applications are abundant. An interim summai was published in 1990 [78]. A further, more up-to-date summary, especially on progress in experimental developments, is much needed. (In Section IV we list some publications that report on the experimental determinations of the Berry phase.) Regarding theoretical advances, we note (in a somewhat subjective and selective mode) some clarifications regarding parallel transport, e.g., [165], This paper discusses the projective Hilbert space and its metric (the Fubini-Study metric). The projective Hilbert space arises from the Hilbert space of the electronic manifold by the removal of the overall phase and is therefore a central geometrical concept in any treatment of the component phases, such as this chapter. 

The electronic theory of organic chemistry, and other developments such as resonance theory, and parallel developments in molecular orbital theory relating to aromatic reactivity have been described frequently. A general discussion here would be superfluous at the appropriate point a brief summary of the ideas used in this book will be given ( 7- )-... 

Other developing or potential appHcations for lime are neutralization of tail gas from sulfuric acid plants, neutralization of waste hydrochloric and hydrofluoric acids and of nitrogen oxide (NO ) gases, scmbbing of stack gases from incinerators (qv), and of course, from small industrial coal-fired boilers. 

Other developments include the attainment of high permeabiUty at cryogenic temperatures (23) for shielding appHcations inside Hquid nitrogen or helium chambers, and temperature stabiHty of near room temperature (24) which is requited in earth-leak transformers. 

In the United States, fibers and injection mol ding are the main appHcations for polypropylene (Table 8), followed by film. In Europe and Japan, injection mol ding appHcations predominate (Table 10). This market area is more likely to decline in economic recession, as consumers postpone purchases of apphances and automobiles. Film appHcations are important in both regions, but fibers are a much less important use for polypropylene in Japan than in other developed regions. The heavy use of polypropylene nonwovens in the manufacture of disposable diapers and similar products, and the wide use of polypropylene carpets in the United States, account for the greater consumption of fibers. 

Worldwide primary aluminum capacity. Table 14 (35), continues to grow but mosdy in countdes where there is low cost electric power. Primary capacity in the United States, Table 15, has been reduced from 5,019 thousand metric tons in 1982 to 3,902 thousand metric tons in 1988. The United States and other developed countries are expected to concentrate mote on converting taw aluminum into high value added products. 

Another type of rotational viscometer is the hehcal-screw rheometer (176). This iastmment is basically a screw-type metering pump that does not pump. The measure of force is the pressure difference resulting from the rotational motion. It is possible to use a bank of pressure transducers of different sensitivities to measure viscosity over a wide range. The iastmment can be used for high temperature rheometry and to foUow polymerkation, shear and heat degradation, and other developments. 

Nonferrous Metal Production. Nonferrous metal production, which includes the leaching of copper and uranium ores with sulfuric acid, accounts for about 6% of U.S. sulfur consumption and probably about the same in other developed countries. In the case of copper, sulfuric acid is used for the extraction of the metal from deposits, mine dumps, and wastes, in which the copper contents are too low to justify concentration by conventional flotation techniques or the recovery of copper from ores containing copper carbonate and siUcate minerals that caimot be readily treated by flotation (qv) processes. The sulfuric acid required for copper leaching is usually the by-product acid produced by copper smelters (see Metallurgy, extractive Minerals RECOVERY AND PROCESSING). 

Other developments in chelating resins include fibers made from poly(ethylene glycol) and poly(vinyl alcohol) to which EDA was attached with epichl orohydrin (281) and a styrene—divinylbenzene resin with pendant EDTA or DETPA groups (282). 

Other developments in recent years have been the appearance of tough and heat-resistant materials closely related to poly(methyl methacrylate) and to interesting cross-linked polymers. Amongst these are the so-called hydrophilic polymers used in the making of soft contact lenses. 

The figure of 4 7o of GNP is probably reasonable for other developed countries, although differences may exist because the mix of industries is not the same—see the data in Table 9.1. Differences in climate, and the level of industrial pollution etc. can be very significant. The cost of corrosion in terms of GNP may well be higher in some less developed countries, although it is probably less in the least developed countries. 

I restrict my attention to non-relativistic pioneer quantum mechanics of 1925-6, and even further to the time independent formulation. Numerous other developments have taken place in quantum theory, such as Dirac s relativistic treatment of the hydrogen atom (Dirac [1928]) and various modern quantum field theories have been constructed (Redhead [1986]). Also, much work has been done in the philosophy of quantum theory such as the question of E.P.R. correlations (Bell [1966]). However, it seems fair to say that no fundamental change has occurred in quantum mechanics since the pioneer version was established. The version of quantum mechanics used on a day-to-day basis by most chemists and physicists remains as the 1925-6 version (Heisenberg [1925], Schrodinger [1926]). 

Parallel to the growth of the engineering science movement was the evolution of the core chemical engineering cnrricnlnm in its present form. Perhaps more than any other development, the core curriculum is responsible for the confidence with which chemical engineers integrate knowledge from many disciplines in the solution of complex problems. 

The EPID concept can be combined with other developments in imaging technology to produce optical devices such as light valves and x-ray imagers. The accompanying illustration shows an example of an electrophoretic x-ray imager. 

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