Coagulated polymers

Isotactic poly(methyl methacrylate/methacrylic acid), a copolymer of methyl methacrylate and methacrylic acid, was synthesized by the partial hydrolysis of isotactic poly(MMA) according to the method of Klesper et al. (10-13). A hydrolyzing mixture of 8 mL dioxane and 4 mL methanolic KOH (10% by weight K0H) was mixed with 250 mg of polymer in closed vials at 85°C for 48 hr. Saponified polymer separated from the solution and adhered to the walls of the vial. The precipitated polymer was dissolved in water and then precipitated again with a few drops of HC1. The solution was warmed and the coagulated polymer removed, washed with water, and dried in vacuo at 50°C. The nmr spectrum indicated approxi-... 

The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of coagulation, polymer-induced forces, and steric stabilization (Chapter 13)... 

The new Chapter 13 collects the material on colloid stability previously distributed between old Chapters 11 and 12 and integrates it with new material on stability ratio and slow and fast coagulation, polymer-induced forces, and polymerinduced stabilization and destabilization. 

Polymers may be induced to encapsulate other molecules by a variety of means (Risch and Reineccius, 1995) as diverse as dipping, spray-drying, extrusion, evaporation, and coacervation each technique has its special applications, strengths, and weaknesses. Advantages in common are the protection and slow release of the encapsulate. In any of the mechanisms, a coagulable polymer precipitates around a core of labile material. Polysaccharides are regular encapsulating polymers (Risch and Reineccius, 1995) acacia gum is particularly efficacious because of its protein content. 

The coagulated polymer was subjected to a series of washings with water, methanol and finally petroleum ether. The sample was then dried to constant weight in a heated vacuum desiccator. 

The per cent conversion was measured after shortstopping with 200 ppm hydroquinone, by coagulating in isopropanol, and then drying to constant weight. The molecular weight was obtained from the viscosity of a 10% solution of coagulated polymer in toluene, as measured in an Ostwald Capillary Viscometer (size 50). The per cent conversion was reproducible to within 15%, while the molecular weight was reproducible to within 50%. 

After the indicated lenth of time, the polymerization was stopped by pouring the contents of the bottle into 100 ml of a coagulant solution (100 gm of hydrated aluminum potassium sulfate and 100 ml of glacial acetic acid diluted to 2.5 liters with distilled water). The coagulated polymer was collected, washed with water, and dissolved in 150 ml of chloroform. Filtering this solution into 300 ml of methanol precipitated the polymer which was then separated by filtration, washed with methanol, and dried under reduced pressure. Inherent viscosities were determined in chloroform at 25°C. Tables III and IV contain the experimental data. 

Uses Antistatic finish for polyester fibers flocculant and coagulant polymers for water treatment, mineral recovery, ion-exchange resins, adhesives, acid dye receptivity retention aid for paper mfg. food-con-tact paper/paperboard Trade Names Ageflex FA-2Q50DMS... 

Pre-treatment system Ultrafiltration, acid DAF, acid, ferric chloride coagulant, polymer, 2-stage dual media filtration Acid, ferric chloride coagulant, polymer, dual media filtration Ferric chloride coagulant, dual media filtration... 

Pre-treatment ACH coagulation, Kme, CO2 30 pm drum screen CIO2, coagulation-flocculation w/ alum PAC, KMnOa, alum, Ume, FeCls, CI2. NH3 PAC. H2SO4, FeS04 CI2, alum coagulation, polymer, sand filter... 

The PVC latex was filtered to remove any traces of coagulated polymer and was used as a seed latex for the second polymerization. New initiator (added in solution form as 0.25 g/10mlH2O), plus TEGDM crosslinker (0.4 wt.% based on acrylonitrile plus butadiene) were stirred into the seed latex. The bottle was then sparged with nitrogen gas for about 5 min and the acrylonitrile monomer was weighed directly on top of the seed latex, 50 wt % based on PVC. Liquefied butadiene was introduced into the bottle directly on top of the floating acrylonitrile. The butadiene was allowed to boil off to the desired amount. The bottle was then capped and put into a 40 C water bath where it was tumbled for a minimum of 12 hr for a completely reacted product. 

Fig. 8, Calculated coagulant-polymer interface for a 20% solution of Nomex in NMP precipitated in water at t = 0.02 s. The figure is for a square lattice of450 x 600 sites only polymer particles (symbol ) have been represented. The figure is for ei 2 = 0.77, 2 3 = 0, and ex 3 = 2.8. Courtesy of Journal of Polymer Science.

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