Stratifier polymerizer

It is likely that some backmixing occurs, especially in the first reactor where fluid viscosities are relatively low. As polymerization proceeds and viscosity increases, the stratified layer condition cited above is gradually approached. 

Figure 17, Dow Chemical Co, patented stratifying polymerization reactor (2J3)...

Finch at (28), show three "stratifying polymerizers" rather than the design combinations described earlier by Ruffing et al (27). The reactors operate at inlet and outlet temperatures respectively of 120 to 135°C, 135 to 145°C, and 145 to 170 C. The first reactor effluent contains 18 to 20% polystyrene and a portion of this stream is recirculated back to the reactor inlet such that the inlet stream polystyrene concentration is as high as 13.5%. This recirculation is claimed to improve rubber phase particle size control and end use properties. 

By far the most typical laser cleaning scheme applied to polymeric systems concerns the removal of unwanted coatings from a substrate. In the simplest case, the problem concerns the removal of polymeric coatings from a metallic or other substrate [14-15]. Other cases may be much more complex, entailing stratified media of varying composition, as for example in the situa-... 

Urban [7] studied the quantitative aspects of alternated total reflectance and photoaconstic step-scan FT-IR and interfacial analysis of polymeric films. There are significant implications arising from the ability to stratify polymer surfaces and interfaces using attenuated total reflectance (ATR) and photoacoustic step-scan FT-IR spectroscopy. Theoretical concepts and... 

Later Thevenin and Muller suggested several modifications to the SEI model (1) the polymer-electrolyte interphase (PEI) model in which the lithium in PC electrolyte is covered with a PEI composed of a mixture of LijCOj, P(PO),and LiClO, P(PO), is polypropylene oxide, formed by reduction-induced polymerization of PC (2) the solid-polymer-layer (SPL) model, where the surface layer is assumed to consist of solid compounds dispersed in the polymer electrolyte (3) the compact-stratified layer (CSL) — in this model the surface layer is assumed to be made of two sublayers. The first layer on the electrode surface is the SEI, while the second layer is either SEI or PEI. The first two... 

Sajjadi [85] investigated the diffusion-controlled nucleation and growth of particle nuclei in the emulsion homopolymerizations of styrene and methyl methacrylate. The polymerization starts with two stratified layers of monomer and water containing surfactant and initiator, with the water layer being stirred gently. In this manner, the rate of transport of monomer becomes diffusion-limited. As a result, the rate of growth of particle nuclei is reduced significantly, and more latex particles can be nucleated in emulsion polymerization. 

The rate and extent of polymerization, degree of oxidation, and film deposition can be controlled by varying the electrode material and its surface structure, the applied potential, and the solution mix, thereby enabling regulation of film microstructure and the amount of enzyme immobilized. In particular, it is possible to generate composite films and multilayers using copolymerization and sequential deposition techniques, and thus fabricate doped and multicatalytic stratified films [162-165]. 

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