Commodity attractiveness

Liquid adsorption processes hold a prominent position ia several appHcations for the production of high purity chemicals on a commodity scale. Many of these processes were attractive when they were first iatroduced to the iadustry and continue to iacrease ia value as improvements ia adsorbents, desorbents, and process designs are made. The UOP Parex process alone has seen three generations of adsorbent and four generations of desorbent. Similarly, Hquid adsorption processes can be applied to a much more diverse range of problems than those presented ia Table 3. 

Since the early 1980s, the viscose-based staple fibers have, like the cuprammonium and viscose filament yams in the 1970s, ceased to be commodities. They have been repositioned from the low cost textile fibers that were used in a myriad of appUcations regardless of suitabUity, to premium priced fashion fibers dehvering comfort, texture, and attractive colors in ways hard to achieve with other synthetics. They are stiU widely used in blends with polyester and cotton to add value, where in the 1980s they would have been added to reduce costs. 

An important property recommending the use of LLDPE in many packaging appHcations is thek sealabHity. CompositionaHy uniform resins are especiaHy attractive for such use because thek melting and softening points are 15—20°C lower than those of commodity LLDPE resins (Fig. 1). 

The type and value of commodity insured (some items are particularly attractive and are always a major target for thieves). 

Enhancing the properties of the relatively cheap commodity plastics through the use of small amounts of reactive modifiers during melt processing (as in method 2(10 above) is both attractive and rewarding. 

Locally prepared products such as stabilized human serum are attractive because the donors from whom the plasma is harvested have an antibody spectrum that most closely matches the needs of patients drawn from the same population. This analysis shows that for an approximately equivalent dose of 6 g of immunoglobulins the local product is less expensive on a gram-for basis. Additionally, a comparison of the antibody titres (Jacobs and Wood, unpublished) showed a broader spectrum than some of the commercially available commodities. Exchange rate = R9.50 = R14.35. 

PHAs can consist of a diverse set of repeating unit structures and have been studied intensely because the physical properties of these biopolyesters can be similar to petrochemical-derived plastics such as polypropylene (see Table 1). These biologically produced polyesters have already found application as bulk commodity plastics, fishing lines, and for medical use. PHAs have also attracted much attention as biodegradable polymers that can be produced from biorenewable resources. Many excellent reviews on the in vivo or in vitro synthesis of PHAs and their properties and applications exist, underlining the importance of this class of polymers [2, 6, 7, 12, 26-32]. 

In contrast to the commodity products, the NP-rich pltmt materitds added to the staple ingredients to give flavour, odour or colour to a food have often had very high value. It is the NPs that humans desire or even crave in their foods, not the nutritional substances. Not only have humans appreciated NPs in their foods, they have also used NPs much more widely. Drinks are more enjoyable if they have a flavour. life becomes more pleasant if the nose is stimulated by the NPs in scents or perfumes. Pills and potions containing NPs, NPs that might have a pharmacological effect, are also more likely to benefit from a placebo effect if they have a distinctive taste. The most extreme case of this interest and attraction to certain NPs is formd in narcotics. 

But why are NP-rich plants more expensive than commodity or crops Simply because, in contrast to the easily substitutable staple foods, the plants that produce highly attractive NPs usually have a much more limited geographical distribution. Consequently, there is less competition in the market place and substitution remains very difficult in most cases (e.g., there is no satisfactory synthetic coffee, tea or chocolate). Some of the NPs used in scents and flavours have been substituted with synthetic chemicals but even then many consumers were prepared to pay a premium for plant-derived flavouring (e.g., natural vs. synthetic vanilla). 

An Approach to Determining the Long-term Attractiveness of Commodity Chemical Businesses... 

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