Specific End Use Research Articles

Selective extraction of native β-lactoglobulin from whey

A method is proposed for the selective extraction from whey of β-lactoglobulin, the major allergenic component of cow milk. It represents an application of subunit exchange chromatography, which exploits the tendency of β-lactoglobulin to undergo reversible association—dissociation equilibria at slightly acidic pH values. Immobilized A and B β-lactoglobulin subunits are capable of interacting in a highly specific and reversible way with the soluble protein and can be used to extract A and B β-lactoglobulin from whey under conditions that favour subunit association. The soluble protein retained by the immobilized protein can be recovered under conditions that promote dissociation into subunits. The subunit exchange column, if coupled to an anion-exchange column, allows the complete deproteinization of whey. All the whey proteins are extracted in their native form and are of high purity; their functional properties are intact even after lyophilization. This important characteristic and the possibility of removing β-lactoglobulin selectively render the proposed method a potentially powerful tool in the processing of whey to produce human food products for specific end-uses such as hypoallergenic milk formulas.

Evaluation of poly(1,4‐cyclohexylene dimethylene terephthalate) blends for improved processability

AbstractPoly(l,4‐cyclohexylene dimethylene terephthalate) (PCT) exhibits superior heat deflection temperature when compared to conventional polyesters such as poly(butylene terephthalate) or poly(ethylene terephthalate). It is subject to degradation, however, at the processing temperatures normally employed to extrude or mold this material. Several approaches were taken to broaden the processing window of this material including: blending PCT with other crystalline and amorphous polymers to allow for lower processing temperatures, addition of conventional stabilizers, addition of crosslinking agents to maintain viscosity during processing and the addition of lubricants to improve processing. Key parameters included physical properties, rate of degradation, extruder torque measurements vs. time, and Differential Scanning Calorimetry (DSC) analysis (melting point and glass transition). All systems tested produced significant reduction of the intrinsic viscosity (molecular weight) for PCT during processing. The most successful approach was the blending of various polymers with PCT to lower extruder processing temperatures. Reductions in processing temperature may have resulted from improved heat transfer due to the presence of a lower melting polymer, reduction in melting point of the blend, or changes in the frictional characteristics of the PCT in the extruder. Transesterification may have played a role in compatibilizing some polyester mixtures. As expected, certain polymers had major'effects on the flow behavior of the blend. Tradeoffs were obtained in physical and thermal properties. A combined approach of polymer blending and the use of lubricants, stabilizers or crosslinking agent may hold the most promise for future development work. Thermal resistance under vapor phase soldering conditions was best for LCP/PCT blends and worst for PBT/PCT blends. Additional evaluations of the blend materials will include solvent resistance, processability, thermal resistance, dimensional stability, heat aging resistance, flammability, and specific end use tests.

Spray drying technology*

The principles of powder production are reviewed. Special mention is made of advances in drying technology which allow the properties of powder to be tailored to specific end use.

FOSFA International arbitration

the Federation of Oils, Seeds and Fats Associations Limited, more succintly known as FOSFA International, is an international trade association which has developed over the years its own system of arbitration procedures for resolving disputes arising out of contracts for the trade in oilseeds, oils and fats and edible nuts. Whilst FOSFA International in its present format dates back only to 1971, it arose out of a merger of four other associations, the oldest dating back to 1863, each of which concerned itself with a specific part or parts of the seed, oil and fat business. Annual world production of oil bearing seeds and nuts is in the region of 180 million tons; total commercial production of oils and fats from these and other oil containing raw materials amounts to some 60 million tons. Oils and fats are essential to the human diet and provide a vital and in some cases major ingredient in a whole range of food products as well as having a variety of non-edible uses. Seeds and nuts may be processed in their country of origin or shipped across the world for processing elsewhere; similarly oils and fats, either in general terms, or of a particular type for specific end use, are shipped from areas of surplus to areas of deficit. These commodities are subject to frequent and sometimes violent price change. In addition to producers, processors, and consumers, the trade involves a variety of other participants: shippers, dealers, merchants, and others who together make up the international market. It is not uncommon for any one parcel of seed or oil to pass through a number of different hands on its way from origin to final point of consumption, nor is it unusual for the same company to buy and sell the same parcel more than …

Coping With Change'' Customs Issues Upstream

Abstract The complications of the National Energy Program have satisfied even the most gregarious appetites: now customs duty issues related to exploration, development and production of Canada's non-renewable energy resources are promising to excite the palate. The menu offers a wide selection: legislative amendments for the conventional; exotic constitutional issues ifyou delight in the offshore. But watch out. it's not always a free meal! This month, Tax Topics reviews some of the emerging issues in the customs area on matters related to resource exploration, development or production. We focus on what's ahead: traps and pitfalls opportunities and savings. Introduction In recent years coping with tax changes has become a daily preoccupation at companies operating in Canada's oil and gas industry. Life as the tax administrator has not been easy or dull. If recent developments in the customs area hold true, the tax administrator will soon have to buy a "customs" hat and, in some cases, he may want to put it on retroactively. This article intends to describe in non-technical terms, a few of the emerging customs issues as they might affect the oil and gas industry, especially the players upstream. Furthermore, for easy reference, a few guidelines to the administration of customs duties are set out in the Appendix. Tariff rates-oil & gas industry Until recently, customs duties have not been of significant concern to companies engaged in conventional drilling programs. As a rule, a series of specific end use tariff items providing low or free rates of duty has governed the importation of a broad range of goods intended for use in the chain of exploration development- production of Canada's oil and gas reserves. The majority of these end use items are found in the 49XXX series of the Customs Tariff. Except where specifically named elsewhere, goods imported for a qualifying end use are dutiable at the rate set out for these end-use classes. Depending on the use, duty is assessed either at rates that range from 8.4% to 12.1% or, as often the case, no duty is assessed. In some cases, the' end use class names the goods (e.g., blow-out preventors, derricks for drilling rigs, draw works); other end use classes refer to a basket clause (e.g., all other machinery and apparatus for use in...). Rates of duty also vary depending on whether or not the named goods or a good falling within a basket clause, "is of a class or kind made/not made in Canada." Finally, so as not to discourage the manufacture in Canada of goods qualifying for low or duty-free end use rates, materials imported for use in their manufacture are allowed duty-free entry. As a result, duty-free status has been gained by companies engaged in conventional drilling programs (or their suppliers) on the purchase or importation of a large portion of their capital acquisitions, including:masts or derricks for drilling, servicing or work-over rigs;drilling, servicing or work-over rigs;well logging equipment;

Copolymerization of 2-Hydroxypropyl Methacrylate with Alkyl Met hacrylates

Abstract 2-Hydroxypropyl methacrylate (2-HPMA) has been copolym-erized with ethyl methacrylate (EMA), n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (EHMA) in bulk at 60°C using benzoyl peroxide as initiator. The copolymer composition has been determined from the hydroxyl content. The reactivity ratios have been calculated by the Yezrielev, Brokhina, and Raskin method. For copolymerization of 2-HPMA (M1) with EMA (M2), the reactivity ratios are r1 = 1.807 ± 0.032 and r2 = 0.245 ± 0.021; with BMA (M2) they are n = 2.378 ± 0.001 and r2 = 0.19 ± 0.01; and with EHMA the values are r1 = 4.370 ± 0.048 and r2 = 0.103 ± 0.006. Since reactivity ratios are the measure of distribution of monomer units in copolymer chain, the values obtained are compared and discussed. This enables us to choose a suitable copolymer for synthesizing thermoset acrylic polymers, which are obtained from cross-linking of hydroxy functional groups of HPMA units, for specific end-uses.

Computer Mapping of Quality Data for Coals in West Virginia--An Aid in Matching a Specific Coal Grade to a Specific End Use: ABSTRACT

In 1907, the first studies of the state's coal reserves were initiated as part of the West Virginia Geological and Economic Survey's statewide geological mapping program. Since then, extensive work has been conducted to map and characterize the state's 62 minable seams. This effort has shown that the coals exhibit a wide diversity of quality, and this diversity provides the coal user a choice of grades to meet specifications for varied applications. Approximately 6,000 coal samples have been analyzed and a computer data base of coal-quality information is now maintained and continues to grow. An extensive coal-quality mapping project makes this information convenient to use. The objective of coal-quality mapping is to produce a series of contour maps showing the variations in coal quality for the most important seams. Parameters being mapped include sulfur, ash, Btu, fuel ratio, Hardgrove grindability, volatile matter, fixed carbon, and kilocalories per kilogram. This type of information is extremely valuable for someone interested in buying, selling, evaluating, or developing West Virginia coal. The maps are computer-generated at a scale of 1:500,000 and End_Page 1174------------------------------ show the trends of coal-quality parameters for individual seams. The maps are supplemented by a computer program that searches the data base and generates a printout of geographical areas within the state where coal has been sampled that meets the desired specifications. These computer techniques go a long way in helping the user to find target areas within the state to match the right coal to the desired end use. End_of_Article - Last_Page 1175------------

Poly(vinyl chloride), Part II: Effect of polymerization temperature and molecular weight on the glass transition and melting point of poly(vinyl chloride)

AbstractA detailed study was made of the thermal behavior of poly(vinyl chloride) (PVC) homopolymers, whose chain length and structure were independently manipulated. Normal PVC polymerizations are made at temperatures, the selection of which determines the polymer chain length. In the case of PVC, this choice of temperature also determines its syndiotacticity, and so, its glass transition temperature, and in many ways, its processibility. The ability to understand how to control chain structure and length in PVC is critical in designing polymers for selected specific end use conditions. The thermal spectrum is known to be one measure of how polymers will perform. This study reveals how such controlled chain length/structure PVCs are characterized by thermal methods, and how one can separate individually the effects of syndiotacticity and molecular weight on thermal properties of poly(vinyl chloride).

Chemistry and characteristics of enzyme‐modified whipping proteins

AbstractProtein derivatives exhibiting aerating and whiping properties are produced by the action of a proteolytic enzyme on a suitable protein substrate, viz., wheat gluten, soy protein or casein. Various proteolytic enzymes can be utilized in the manufacture of the modified protein derivatives, but those enzymes displaying maximum proteolytic activity in the acid pH range produce whipping proteins with optimum aerating functionality and maximum stability characteristcs. Reaction parameters for the hydrolysis include: type of enzyme, enzyme concentration, temperature, pH and time of reaction. By careful control of these variables, modified proteins with unique and exceptional whipping properties can be produced. Enzyme‐modified whipping proteins are bland, light cream‐colored, spray‐dried powders, soluble in hot or cold water, and functional over the entire pH range. Depending upon the source, protein and conditions of manufacture, products can be produced with a protein content ranging from as low as 50% to as high as 85%, and a whipping functionality equal to or twice that of egg albumen. Unlike egg albumen, these products do not coagulate to any appreciable degree when heated, and depending upon the specific end use of the product, this property may be either an advantage or disadvantage.

Some terminally-functionalized species

Terminally-functionalized species are, of course, as old as polymerization. We believe that the synthesis of polymers designed for specific end-uses (e.g. for medical or catalytic applications) is one of the most important growth areas in polymer science; clearly, this will require development of increasingly precise methods of polymer functionalization. This lecture is concerned with the synthesis and reactions of some terminally-functionalized polymers which we have studied in recent years. In general, polymers functionalized in this way have evident uses in the synthesis of block and graft copolymers; furthermore, in suitable cases, they afford an important way of studying interactions of electronically excited chromophores with ground-state species, in particular the dependence of such interactions on polymer chain conformations. We shall consider both these aspects.

A study of the effect of branching on certain physical and mechanical properties of stereoregular polypropylene

AbstractThe properties of stereoregular polypropylene have been modified by the introduction of controlled branching into the polymer chain backbone. Branching is achieved by copolymerizing propylene with certain long‐chain 1‐olefins by using a standard Ziegler Natta low pressure catalyst. Physical and mechanical properties of the copolymers are related to the degree and length of branching. It was found that ultimate strength properties of moderate molecular weight polymers could be improved at some expense in short‐range deformation properties by adjusting the degree of branching to a suitable level. The copolymers did not show a good combination of low temperature brittleness characteristics along with higher temperature strength properties. It is suggested that the branching technique described will allow the tailoring of polypropylene resins for specific end use applications.

A statistical study of the effect of formulation variables on the properties of sorbitol polyether‐based rigid urethane foam

AbstractEach rigid urethane foam formulation must be carefully designed to meet the key requirements of its specific end use. For example, refrigerator insulation is an application which requires low thermal conductivity, low density, and excellent resistance to humid aging. The present investigation was carried out to determine variations in foam properties caused by changes in catalyst concentration, isocyanate/hydroxyl ratio in the quasi‐prepolymer, quasi‐prepolymer cooking time, dispersing agent concentration, and isocyanate/hydroxyl ratio in the total foam. The basic foam formulation contained sorbitol polyether (Hydroxyl Number 490), toluene diisocyanate, trichlorofluoromethane blowing agent, catalyst, and dispersing agent. The results showed that the tensile strength decreased as the isocyanate/hydroxyl ratio in the total foam increased. Shear strength was affected strongly by catalyst concentration, and by isocyanate/hydroxyl ratio in the prepolymer and in the total foam. Cure time (at room temperature) was strongly affected by catalyst concentration and technique of prepolymer preparation. The only factors having a significant effect on humid aging resistance were isocyanate/hydroxyl ratio in the prepolymer and in the total foam. The effects on thermal conductivity were complex, and included an interaction between dispersing agent concentration and catalyst concentration, and also between prepolymer preparation technique and isocyanate/hydroxyl ratio in the prepolymer. The compressive strength increased with catalyst concentration, and was strongly affected by prepolymer preparation techniques. Key effects and interactions were plotted in graphical form.