Co-coagulation

Blends with PVC. Nitrile mbber may be blended with poly(vinyl chloride) (PVC) by the polymer producer by two different techniques (1) blending of NBR latex with PVC latex followed by co-coagulation and drying, or (2) physically mixing the soHd NBR and PVC powder in mixing equipment such as an internal mixer. NBR—PVC polymer blends are well known for the good ozone resistance that is imparted by the PVC. 

Another application of PTFE dispersions is the preparation of a variety of compositions with other materials, such as mineral fillers, other polymers in powdered form by co-coagulation. The dispersion of the other component is blended with the PTFE dispersion and the blend is then coagulated. The resulting composition can be processed by extrusion with lubricants (see processing of fine powders) or by compression molding.16... 

Co-coagulation is the method by which large quantities of fillers can be incorporated in dispersion polymerized polytetrafluoroethylene. The addition of fillers takes place prior to coagulation of the resin from its dispersion state. In the process of co-coagu-lation, the additives are added to the polytetrafluoroethylene dispersion and mixed. This dispersion is coagulated and the compound is recovered. The smaller the filler particles, the smaller the points of stress rise in the compound will be. Significantly larger quantities of filler can be compounded in PTFE by this technique. 

Co-coagulated compounds can also be molded into thick sections. In this case, the surfactant should be removed by heating the material for 4 hours at 300°C. The lumps formed during this step can be broken by chilling and pulverizing. 

Co-coagulation - This is a process in which other species are added to polytetrafiuoroethylene dispersion, followed by coagulation. See also DU Bearing Process and Coagulation. 

CO COAGULANT - A substance that promotes the clumping of particulate matter in water, forming a larger mass and thus promoting settling of particulates and clarification of the water. 

CNT and CB dispersed in NR latex through ultrasonic assisted mixing process exhibited a synergistic reinforcing effect when co-coagulated, with a maximum of mechanical properties at 20 5 as CB/CNT weight ratio." ... 

Wu et prepared NR/clay nanocomposites by directly co-coagulating the rubber latex and clay aqueous suspension. This preparative process is very simple, convenient and elfective. SEM showed good dispersion of clay in the NR matrix, and these novel NR/clay nanocomposites exhibited excellent mechanical and gas barrier properties. 

Wu, Y.P., Zhang, L.Q., Wang, Y.Q., Liang, Y., Yu, D.S. Structure of caiboxylated acrylonitrile-butadiene rubber (CNBR)-clay nanocomposites by co-coagulating lubber latex and clay aqueous suspension. J. AppL Polym. ScL 82(11), 2842-2848 (2001)... 

This synthesis, undertaken by Klempner, Frisch, and Frisch " " makes use of two noninteracting types of latexes. These are synthesized separately as linear polymers, mixed together, along with crosslinkers and catalysts, and co-coagulated. The material is then subjected to a simultaneous crosslinking step via heating. Table 5.4 delineates materials employed in the synthesis. " One latex usually was a polyurethane. 

Hodag floes 111,115, 118,119,120, etc High polymer(nonionic, cationic, anion) Bridging, electrolyte, co-coagulating 2-12 5 % (for storing) 1 % (for using) 0.5-1.5 ppm... 

The possibility of co-coagulating cyclized rubber latex with uncyclized latex to give an intimate mixture of cyclized and uncyclized rubber, which can then be used as a masterbatch for incorporating cyclized rubber into NR compounds. 

Some may use the combined latex compounding and melt mixing approach to produce natural rubber nanocomposites. For instance, natural rubber/Ca-montmorillonite (Ca-MMT) nanocomposites with well exfoliated Ca-MMT were prepared by a combination of latex compounding and melt mixing. Firstly, a high Ca-MMT content masterbatch was co-coagulated by natural... 

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