Polyvinylchloride particles

Volkheimer, G., 1975, Hematogenous dissemination of ingested polyvinylchloride particles, Ann. N. Y. Acad. Set 246 164-171. 

Transition from liquid behavior to solid behavior has been reported with fine particle suspensions with increased filler content in both Newtonian and non-Newtonian liquids. Industrially important classes are rubber-modified polymer melts (small rubber particles embedded in a polymer melt), e.g. ABS (acrylo-nitrile-butadiene-styrene) or HIPS (high-impact polystyrene) and fiber-reinforced polymers. Another interesting suspension is present in plasticized polyvinylchloride (PVC) at low temperatures, when suspended PVC particles are formed in the melt [96], The transition becomes evident in the following... 

Hoinkins et al., (1967) glued the ion exchange particles to a cylinder that rotated in the solution and could be easily removed and reimmersed. Bunzl (1974b) attached peat particles to a polyvinylchloride (PVC) cylinder with self-adhesive tape. The cylinder, which had a small propeller at its lower end, was rotated at 470 rpm in an H solution to saturate the peat. Then the cylinder was dipped in Pb(N03)2 and removed at certain times. Interruption tests showed that FD was rate-limiting for Pb-H exchange on peat. 

Examples of particle sizing using photon correlation spectroscopy are presented to demonstrate the straight forward uses and difficulties with the technique. Examples include NBS SRM 1691, a crosslinked polystyrene-divinylbenzene, a fractionated sample of polyvinylchloride, "dusty" samples of reference latex, a bimodal mixture of reference latices, a bimodal mixture of rubber particles, and a 2 1 aggregate. 

In micro- and ultrafiltrations, the mode of separation is by sieving through line pores, where microfiltration membranes filter colloidal particles and bacteria from 0.1 to 10 mm, and ultrafiltration membranes filter dissolved macromolecules. Usually, a polymer membrane, for example, cellulose nitrate, polyacrilonytrile, polysulfone, polycarbonate, polyethylene, polypropylene, poly-tretrafhioroethylene, polyamide, and polyvinylchloride, permits the passage of specific constituents of a feed stream as a permeate flow through its pores, while other, usually larger components of the feed stream are rejected by the membrane from the permeate flow and incorporated in the retentate flow [10,148,149],... 

Figure 1.2. Izod impact strength at room temperature as a function of diameter of elastomeric particles in methylmethacrylate-butadiene-styrene copolymer used for toughening polyvinylchloride resin [after Bertelo and Mori, 1994].

In the polymer industry, packing material, laminates including multilayer films, pellets or molded products can be analyzed by NIR. Even polymer latex particles with up to 99 % water content may be analyzed. NIR provides information about reaction mechanisms, polymerization, crystallinity, orientation, water content and hydrogen bonding, even during the process of polymer manufacture. For example the disappearance of the double bonds in polyethylene and polypropylene can be monitored. In the NIR spectrum C=C bonds lead to a combination band at about 4740 cm and a first overtone at about 6170 cm NIR spectroscopy is applied to characterize ester-, nitrile-, or amide-based acrylic and methacrylic polymers. Other examples are the identification of polyvinylchloride, polyvinyl alcohol and polyvinyl acetates or the analysis of polymerization in epoxy and phenolic resins. 

FIGURE 27.10 Schematic of a particle caster. (Reprinted with permission from Tsagkatakis, I., Peper, S., Retter, R., Bell, M., and Bakker, E., Monodisperse plasticized Polyvinylchloride fluorescent microspheres for selective ionophore-based sensing and extraction, Ana/. Chem., 73, 6083-6087, 2001. Copyright 2001 American Chemical Society.)... 

The term gelation is used in extruded products made of rigid polyvinylchloride (PVC). The term gelation is the fusion of the primary particles of the PVC [164]. In... 

Hunt and co-workers [21] nsed SFC to extract additives in polyvinylchloride (PVC). The extraction time, temperature and pressure were varied in order to determine the optimum supercritical fluid extraction (SFE) conditions. The effects of the particle size of the sample and the addition of methanol to the extraction fluid were also investigated. The separation and qnantification of individual components in the PVC extracts were... 

The dispersion of fibers in polymer latex to prepare composite has been reported for poly(6-hydroxyoctanoate) (PHO) [101, 102], polyvinylchloride (PVC) [103], waterborne epoxy [104] and polyvinyl acetate (PVAc) [94]. Most of the works focus on the use of non-polar, non-water-sensitive polymers, while keeping an aqueous media for the processing of the films to preserve the dispersion of the nanoparticles. In their pioneering work, Favier et al [94] adopted the technique of solvent casting using a synthetic latex obtained by the copolymerization between styrene (35 wt%) and butyl-acrylate (65 wt%) (poly(S-co-BuA)). Nanowhiskers were dispersed in the latex and evaporated. The nanocomposite films were obtained by water evaporation and particle coalescence at room temperature, that is at a temperature higher than Tg of poly(S-co-BuA), around 0 C. 

Figure 7 shows the embrittlement filler content (f) plotted against the ratio of the strength to the draw stress Om/c dni- 4> increases with an increase in the critical volume fraction for polyvinylchloride (PVC) is less than 0.05, and is not improved by toughening with rubber particles. If a polymer does not strain-harden, even a small amount of filler leads to loss of ductility. The critical volume fractions for polypropylene (PP) and for copolymers of polyethyleneterephthalate (PET), Kodar 6763, are higher, from 0.1 to 0.2. The critical filler content of... 

In some cases, larger conducting polymer particles have been mixed with other pol5uners. For example, Bose and co-workers incorporated chemically synthesized PPy into polyvinylchloride (PVC) or nafion. After casting, the materials were shown to be electroactive and demonstrate elec-trocatalytic properties. 

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