Butadienes material factor

STATE OF OPERATION DESIGN START UP X NORMAL OPERATION SHUTDOWN BASIC MATERIAL(S) FOR MATERIAL FACTOR Butadiene ... 

The development of new polymer alloys has caused a lot of excitement in recent years but in fact the concept has been around for a long time. Indeed one of the major commercial successes of today, ABS, is in fact an alloy of acrylonitrile, butadiene and styrene. The principle of alloying plastics is similar to that of alloying metals - to achieve in one material the advantages possessed by several others. The recent increased interest and activity in the field of polymer alloys has occurred as a result of several new factors. One is the development of more sophisticated techniques for combining plastics which were previously considered to be incompatible. Another is the keen competition for a share of new market areas such as automobile bumpers, body panels etc. These applications call for combinations of properties not previously available in a single plastic and it has been found that it is less expensive to combine existing plastics than to develop a new monomer on which to base the new plastic. 

Again, with the knowledge that NR had isoprene units, chemists worked to duplicate the synthesis of rubber except using synthetic monomers. These attempts failed until two factors were realized. First, after much effort it was discovered that the methyl groups were present in a cis arrangement. Second, it was not until the discovery of stereoregular catalysts that the chemists had the ability to form NR-like material from butadiene. 

Comparing the routes shown in Figure 2.35 with those shown in Figure 2.36, the main evident difference is that in one case the starting raw material is cyclohexane while in the other it is propene or butadiene. A critical factor would thus be the availability and cost of these raw materials. We may observe that the route from propene or butadiene is also completely catalytic and does not produce ammonium... 

Scalco, Huseby, and Blyler (8), Zosel (9), and Bergen and Morris (10). Prest and Porter (23) applied the same principle to homopolymer blends [poly (2,6-dimethylphenylene oxide)-polystyrene]. Recently some papers were published on triblock copolymers of styrene-butadiene-styrene and on their blends with polybutadiene (24, 25). Triblock copolymers can be considered heterophase material as the different constituent blocks are thermodynamically incompatible with each other, and, consequently, polystyrene domains are enclosed in polybutadiene (continuous matrix). The findings indicate that these systems are in general thermorheologically complex, so that the shift factor ar depends not only on temperature but also on time. These conclusions have been extrapolated to other two-phase systems. 

In spite of the above-mentioned factors that might interfere with correlations between surface areas and catalytic activity, it has often been found that a good correlation does exist. For example it has been pointed out in a paper by Owen (38) that the catalysts used in dehydrogenating butene to form butadiene have activities that are directly proportional to the total surface areas. For such materials the surface area measurements may serve as a good control for predicting the activity that will be possessed by a given catalyst. 

Though how optimized and elaborate the process has become, it competes with other routes. For adiponitrile, the nickel-catalyzed hydrocyanation of butadiene is today regarded as the most cost-effective route [28]. This route has originally been developed at DuPont [27] and it is sensitive to the natural gas price, while for the electrohydrodimerization, the propylene price is of interest. Today adiponitrile is produced for the most part by hydrocyanation [28]. This makes an industrial aspect of organic electrochemistry very clear the electrolysis has to generate a profitable product. The efficiency of a process with high yields is one step to this profitable product. In the end factors like the raw material basis may make the difference between being competitive and not especially for a commodity like adiponitrile. 

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