Polyacrylamide manufacturing process

Polyacrylamide El, with the lowest electrochemical degradation factor of 11.2 in Table 3, experiences the smallest reduction of resistance factor in the presence of univalent and divalent electrolytes, from 55.9 in river water to 49.5 in an 80/20 mixture of river and formation waters. These unusually large resistance factors probably resulted from the hydrodynamic resistance of the long linear polymer chain which is a unique characteristic of its gamma radiation manufacturing process. There appears to be some correspondence between the effect of electrolytes on viscosity and screen factor since polymers C and D1 with the lowest electrochemical degradation exhibit the greatest reduction in screen factor on... 

Aciylamide is required in very large quantities as the pre-polymer of the polyacrylamide that is very widely used in polymer and flocculant apphcations. The chemical manufacture of acrylamide has been estabhshed for a long time. The original process involved treatment of acrylonitrile with sulphuric acid at 90°C. More recently processes have been introduced that require the use of copper catalysts and high temperatures (80-140°C), but result in the formation of large quantities of toxic waste, including HCN. The expensive copper catalyst used is difficult to regenerate. In addition the chemical process produces aciylamide that requires considerable purification, for instance because the... 

Quantitative conversion of acrylonitrile is achieved so that separation of acrylamide from umeacted acrylonitrile is no longer necessary. A key advantage of this process appears to be that because less impurities are produced by the microbial process, polyacrylamide of higher molecular weight can be manufactured so that lower in-use concentrations can be used, creating considerable savings for the end-user. 

The purple membrane is harvested semiindustrially from halobacteria mutants which are bred in fermenters. The BR is then embedded into a polymeric matrix of poly(vinyl alcohol) or polyacrylamide. The BR films manufactured in this way are used for different applications, preferably in holography, for example, as a reversible transient data storage system for optical information processing (159). Another example is real-time interferometry by using the property of BR films to integrate over time (160). BR has been proposed also as a two-photon memory material because of its unusually large two-photon cross section. 

Environmentally Friendly Polyacrylamides, in recent years, commercial processes that use biodegradable oils to replace petroleum hydrocarbons have received a great deal of attention. Also, there has been a great deal of interest in polymerization in supercritical fluids. These future directions for the manufacture of polyacrylamides are summarized in the following. 

Microcarrier culture Microcarriers are small particles, usually spheres 100 to 300 fim in diameter that are suspended in stirred culture medium. The technique was initiated in 1967 but required considerable developmental work to produce a range of suitable microcarriers (e.g., the Cytodex series by Pharmacia). The first industrial process based on microcarriers was for FMDV. Subsequently, a wide range of microcarriers based on gelatin, collagen, polystyrene, glass, cellulose, polyacrylamide, and silica have been manufactured to meet all situations. The key criteria in the design of effective microcarriers were to make the surface chemically and electrostatically correct... 

The two main polymers produced for lOR, hydrolysed polyacrylamides and xanthan biopolymer, are produced commercially by quite different processes. Polyacrylamides are synthesised in industrial reactors and biopolymers are produced in industrial fermenters. In this section, a very brief outline of the industrial manufacture of xanthan and polyacrylamide is presented. This is intended only to give the reader a brief background knowledge of the processes involved in producing polymers for this application it is not intended to be in any way comprehensive or complete. 

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