Polystyrene compatibility studies

Naidu, B. V. K., MaUikarjuna, N. N., and Aminabhavi, T. M. 2004. Blend compatibility studies of polystyrene/poly(methyl methacrylate) and polystyrene-acrylonitrile by densitometry, viscometry, refractometry, ultraviolet absorbance, and fluorescence techniques at 30°C. Journal of Applied Polymer Science 94 2548-2550. 

Singh, Y.P. and Singh, R.P. (1983) Compatibility studies on solid polyblends of poly(methyl methacrylate) with poly (vinyl acetate) and polystyrene by ultrasonic technique. J. Eur. Polym., 19, 529-533. 

The major advantage of the capillary hydrodynamic chromatography is that the mobile phase does not need to have similar solubility parameter as the sample and packing material. (In SEC, nonsize exclusion effects may be observed if the solubility parameter of the sample, packing material, or mobile phase is considerably different.) Therefore, the hydrodynamic size of polymers can be studied in a 0 solvent and even in a solvent that is not compatible with any currently available SEC packing material (9). Figure 22.4 is an example of polystyrene separation in both THF and diethyl malonate. Diethyl malonate is the 0 solvent of polystyrene at 31-36 C. 

Much work on the preparation of nonaqueous polymer dispersions has involved the radical polymerization of acrylic monomers in the presence of copolymers having the A block the same as the acrylic polymer in the particle core 2). The preparation of polymer dispersions other than polystyrene in the presence of a PS-PDMS diblock copolymer is of interest because effective anchoring of the copolymer may be influenced by the degree of compatibility between the PS anchor block and the polymer molecules in the particle core. The present paper describes the interpretation of experimental studies performed with the aim of determining the mode of anchoring of PS blocks to polystyrene, poly(methyl methacrylate), and poly(vinyl acetate) (PVA) particles. 

In our studies we found that phosphonic acids (16), phosphinic acids (25), and phosphine oxides (17) are additives capable of imparting fire retardant properties to thermoplastic polymers. Tables I and II present data for some of these compounds when added to polyethylene or to poly (methyl methacrylate). The concentration reported is not necessarily the lowest effective concentration for the additive in the polymer. These additives also were effective in other thermoplastic polymers such as polystyrene, impact polystyrene, polypropylene and ABS. The compounds were completely compatible with the polymers. 

The observation in 1949 (4) that isobutyl vinyl ether (IBVE) can be polymerized with stereoregularity ushered in the stereochemical study of polymers, eventually leading to the development of stereoregular polypropylene. In fact, vinyl ethers were key monomers in the eady polymer literature. For example, ethyl vinyl ether (EVE) was first polymerized in the presence of iodine in 1878 and the overall polymerization was systematically studied during the 1920s (5). There has been much academic interest in living cationic polymerization of vinyl ethers and in the unusual compatibility of poly(MVE) with polystyrene. 

A study of column extraction of metals was carried out using pre-packed columns available from Polymer Laboratories (now a part of Varian, Inc.) [6]. Trace metals in these monomers would have a detrimental effect on the stability of anaerobic adhesive products and must be absent prior to use. The columns used are specially coated macroporous polystyrene products that are compatible with polar, non-polar, protic and aprotic solvents. They are designed to remove metals from solvents and monomers. The metal removing SPE product is approximately 45 pm and based on a mono-dispersed macroporous polymeric material. 

The polyethylene latexes obtained in the different emulsion polymerization procedures using the various aforementioned nickel(II) complexes display average particle diameters of 100 to 600 nm. A number of anionic surfactants or neutral stabilizers are suitable, i.e. compatible with the catalysts and capable of stabilizing the latex. Solids contents of up to 30% have been reported to date. A typical TEM image is shown in Fig. 7.2. By comparison to smooth, spherical latex particles of amorphous polystyrene as a well studied hydrocarbon polymer prepared by free-radical emulsion polymerization, the ruggedness of the particles shown can be rationalized by their high degree of crystallinity. 

Mixtures of polymer chain belonging to the same chemical species but with different isotopic compositions (deuterated and non-deuterated) have been widely used for experimental studies of polymer structures, since good neutron beams became available. This technique, combining the preparation of adequate samples and neutron scattering experiments, enabled the experimentalists to determine the size of polymer chains (polystyrene or polydimethylsiloxane), in all kinds of polymer mixtures or concentrated polymer solutions. However, the technique relies on the fact that the deuterated and non-deuterated isotopic varieties of a same polymer are compatible with one another. It is admitted that under the experimental conditions described above, the mixture constitutes a unique phase. In fact, the mixing energy of deuterated and non-deuterated chains is probably very small. However, it is non-zero, in particular, because of differences in atomic volumes and polarizabilities. Thus, there is no doubt that demixtion may occur in mixtures of deuterated and undeuterated chains of very high molecular masses. 

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