Poly polystyrene compatability

In general, the azo colors are useful for coloring polystyrene, phenoHcs, and rigid poly(vinyl chloride). Many are compatible with poly(methyl methacrylate), but in this case the weatherabiUty of the resin far exceeds the life of the dyes. Among the more widely used azo dyes (qv) are Solvent Yellows 14 and 72 Orange 7 and Reds 1, 24, and 26. 

The anthraquinones are useful in acrylics and are compatible with polystyrene and ceUulosics. Solvent Red 111 has a special affinity for poly(methyl methacrylate) as the red in automobile taillights exposure for a year in Florida or Arizona produces only a very slight darkening. Acid types are usehil for phenohcs (see Dyes, anthraquinone). 

It is worth noting that occasionally high Tg compatible additives are incorporated into the polystyrene phase, when the PSA requires higher temperature performance. These additives are usually based on poly-a-methylstyrene. 

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. 

The heat distortion temperature of impact-resistant polystyrene may also be improved by polymer blends. Those of impact-resistant polystyrene with poly-2,5-dimethylphenylene-1,4-oxide (PPO) are particularly interesting (90). Polystyrene and PPO are molecularly compatible and mixtures of them have glass transition temperatures which vary virtually linearly with composition. A further advantage of these compositions which should not be under-estimated is their better flame resistance. 

Finally, we should mention the phenomenon of incompatibility of mixtures of polymer solutions. It applies to nearly all combinations of polymer solutions when the homogeneous solutions of two different polymers in the same solvent are mixed, phase separation occurs. For example, 10% solutions of polystyrene and poly(vinyl acetate), each in benzene, form two separated phases upon mixing. One phase contains mainly the first polymer, the other phase mainly the second polymer, but in both phases there is a certain amount of the other polymer present. This limited compatibility of polymer mixtures can be explained thermodynamically and depends on various factors, such as the structure of the macromolecule, the molecular weight, the mixing ratio, the overall polymer concentration, and the temperature. 

Mutually compatible polymers are relatively rare [84,85], A typical phase diagram of two incompatible polymers and a common solvent is that determined by Kern for the polystyrene - poly(p - chlorostyrene) - benzene system shown in the Fig. 1.11 [86],... 

The ionic aggregates present in an ionomer act as physical crosslinks and drastically change the polymer properties. The blending of two ionomers enhances the compatibility via ion-ion interaction. The compatibilisation of polymer blends by specific ion-dipole and ion-ion interactions has recently received wide attention [93-96]. FT-IR spectroscopy is a powerful technique for investigating such specific interactions [97-99] in an ionic blend made from the acid form of sulfonated polystyrene and poly[(ethyl acrylate - CO (4, vinyl pyridine)]. Datta and co-workers [98] characterised blends of zinc oxide-neutralised maleated EPDM (m-EPDM) and zinc salt of an ethylene-methacrylic acid copolymer (Zn-EMA), wherein Zn-EMA content does not exceed 50% by weight. The blend behaves as an ionic thermoplastic elastomer (ITPE). Blends (Z0, Z5 and Z10) were prepared according to the following formulations [98] ... 

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. 

Figure 1. Room-temperature miscibility diagrams for blends of polystyrene with poly(methyl methacrylate) and styrene/(methyl methacrylate) copolymers. Shaded area is compatible region.

On the other hand, some mechanically compatible blends as well as some dispersed two-phase systems have made respectable inroads into the commercial scene. Many of these are blends of low-impact resins with high-impact elastomeric polymers examples are polystyrene/rubber, poly (styrene-co-acrylonitrile) /rubber, poly (methyl methacrylate) /rubber, poly (ethylene propylene)/propylene rubber, and bis-A polycarbonate/ ABS as well as blends of polyvinyl chloride with ABS or PMMA or chlorinated polyethylene. 

In the methodology developed by us [24], the incompatibility of the two polymers was exploited in a positive way. The composites were obtained using a two-step method. In the first step, hydrophilic (hydrophobic) polymer latex particles were prepared using the concentrated emulsion method. The monomer-precursor of the continuous phase of the composite or water, when that monomer was hydrophilic, was selected as the continuous phase of the emulsion. In the second step, the emulsion whose dispersed phase was polymerized was dispersed in the continuous-phase monomer of the composite or its solution in water when the monomer was hydrophilic, after a suitable initiator was introduced in the continuous phase. The submicrometer size hydrophilic (hydrophobic) latexes were thus dispersed in the hydrophobic (hydrophilic) continuous phase without the addition of a dispersant. The experimental observations indicated that the above colloidal dispersions remained stable. The stability is due to both the dispersant introduced in the first step and the presence of the films of the continuous phase of the concentrated emulsion around the latex particles. These films consist of either the monomer-precursor of the continuous phase of the composite or water when the monomer-precursor is hydrophilic. This ensured the compatibility of the particles with the continuous phase. The preparation of poly(styrenesulfonic acid) salt latexes dispersed in cross-linked polystyrene matrices as well as of polystyrene latexes dispersed in crosslinked polyacrylamide matrices is described below. The two-step method is compared to the single-step ones based on concentrated emulsions or microemulsions. 

Robard, A. Patterson, D., "Temperature Dependence of Polystyrene-Poly(vinyl methyl ether) Compatibility in Trichloroethane," Macromolecules, 10, 1021 (1977). 

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