Purification of Polymers

Prokop A, Wang T (in preparation) Purification of polymers for use in immunoisolation... 

Ultrafiltration (UF) pressure difference protein recovery purification of polymer solutions... 

Dialysis concentration difference purification of polymer solutions hemodialysis... 

The monomer imit structure of the vehicle and its molecular weight and viscosity control the behavior of the vehicle. In the manufecture and purification of polymers, a range of molecular sizes is usually present in the final product. 

Two interesting conclusions can be drawn. First, there has been much controversy in the literature about the relative importance of the various possible mechanisms for initiation (ketone groups, hydroperoxide, catalyst residues, singlet oxygen), but the controversy is practically irrelevant if initiation does not much influence the course, rate or extent of photooxidation. Second, in terms of stabilization, minute amounts of photoinitiation will lead to practical failure so that the purification of polymers to minimize the initiating residue is not a practical alternative for stabilization. Both points underline the value of this approach to the understanding of the complex photooxidation process. 

Precipitation from poor solvents is routinely used in purification of polymers and in many or most cases is part of the synthetic workup used in making the polymer-immobilized catalysts described throughout this review. Solvent precipitation is also sometimes used incidentally as a way to recover catalysts that are more commonly recovered in some other way. Examples of this are seen in the use of hexane to precipitate the poly(AT-alkylacrylamide)-bound Pd-phosphine complexes 76 and 77 or the poly(JV-terf-butylacry-lamide)-bound sulfonic acid catalyst 78 [115-117], catalysts that are routinely recovered as solids by thermal precipitation (vide infra),... 

Purification of polymers is performed by standard techniques that have previously been established for recombinant proteins. Frequently these include the use of affinity tags [e.g., poly(histidine), glutathione-s-transferase] that can be used to chromatographically purify recombinant proteins. If necessary, the tag can subsequently be removed by enzymatic cleavage. 

Prokop A, Wang T (in preparation) Purification of polymers for use in immunoisolation Vogel MK, Cross RA, Bixter HJ (1970) J Macromol Sci Chem A4 675 Domard A, Rinaudo M (1980) Macromolecules 13 898 Troung ND, Gafin JC, Francois J, Pham QT (1986) Polymer 27 459 Himkeler D (1990) PhD Thesis, McMaster University, Hamilton, Ontario, Canada GroboiUot A, Boadi DK, Poncelet D,Neufeld RJ (1994) Critical Reviews in Biotechnology 14 75... 

Kleintjens L.A., (1989), Purification of Polymers by supercritical fluid extraction in processing machines. Integration of Pol.Sci. Technology 3. Elsevier Appl. Sci., London, 91. 

PURIFICATION OF POLYMERS BY SUPERCRITICAL FLUID EXTRACTION IN PROCESSING MACHINES... 

In the following these three steps are discussed for the purification of polymer material by SFE. 

This early work was followed intermittently by a flurry of activity that intensified diuing the 1970s and 1980s, partly as a result of environmental concerns over the use of conventional solvents. Major commercial processes currently in use are the SCE of caffeine from coffee and tea, the SCE of spice aromas, and the fractionation and purification of polymers. Processes under investigation include the treatment of wastewaters, activated carbon regeneration, and the SCE of edible oils and therapeutic agents from plant materials. 

Prokop A, Wang TG. Purification of polymers used for fabrication of an immunoisolation barrier. In Prokop A, Hunkeler D, Cherrington AD, eds. Bioartificial Or ns. New York NY Acad Sci,... 

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