Polystyrene blend with poly methyl

In the case of polystyrene blends with poly(vinyl methyl ether) two phase behaviour was found for blends from various chlorinated solvents whereas single phase behaviour was found for blends from toluene The phase separation of mixtures of these polymers in various solvents has been studied and the interaction parameters of the two polymers with the solvents measured by inverse gas chromatography It was found that those solvents which induced phase separation were those for which a large difference existed between the two separate polymer-solvent interaction parameters. This has been called the A% effect (where A% = X 2 Xi 3)-A two phase region exists within the polymer/polymer/solvent three component phase diagram as shown in Fig. 2. When a dilute solution at composition A is evaporated, phase separation takes place at B and when the system leaves the two phase region, at overall... 

The best characterized system has been polystyrene blended with poly(vinyl methyl ether). Several studies showed that this system is miscible... 

As with other rigid amorphous thermoplastic polymers such as PVC and polystyrene (see the next chapter) poly(methyl methacrylate) is somewhat brittle and, as with PVC and polystrene, efforts have been made to improve the toughness by molecular modification. Two main approaches have been used, both of which have achieved a measure of success. They are copolymerisation of methyl methacrylate with a second monomer and the blending of poly(methyl methacrylate) with a rubber. The latter approach may also involve some graft copolymerisation. 

Examples of known phosphazene polymer blends are those in which phosphazenes with methylamino, trifluoroethoxy, phenoxy, or oligo-ethyleneoxy side groups form blends with poly(vinyl chloride), polystyrene, poly(methyl methacrylate), or polyethylene oxide).97 100 IPNs have been produced from [NP(OCH2CH2OCH2CH2OCH3)2] (MEEP) and poly(methyl methacrylate).101-103 In addition, a special type of IPN has been reported in which a water-soluble polyphosphazene such as MEEP forms an IPN with a silicate or titanate network generated by hydrolysis of tetraethoxysilane or tetraalkoxytitanane.104 These materials are polyphosphazene/ceramic composites, which have been described as suitable materials for the preparation of antistatic layers in the manufacture of photographic film. 

Physical Properties of Blends of Polystyrene with Poly(methyl Methacrylate) and Styrene/ (methyl Methacrylate) Copolymers... 

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

Evidence from spectral studies for interactions other than the above hydrogen bonds is not very plentiful. Polystyrene/poly(2,6 dimethyl-l,4-phenylene oxide) blends have been studied by infra-red and ultraviolet spectroscopy . Interactions involving the aromatic rings of the two polymers were proposed. Studies of low molecular weight ethers with aromatic compounds have shown evidence for specific interactions and this has recently been extended to blends of polystyrene with poly(methyl vinyl ether)... 

The application of this technique as a morphological tool requites that there be a close coupling between polymer photophysics and polymer physics. In the photophysical studies described in this paper emphasis will be placed on the development of analytical models for electronic excitation transport (EET). The areas of polymer physics that we will consider involve the configurational statistics of Isolated chains and phase separation in multicomponent polymer systems. The polymer system of primary interest is the blend of polystyrene (PS) with poly(vinyl methyl ether) (PVME). 

Figures 3.1 and 3.2 compare the dCp/dT versus temperature data from experiments with theoretical data (using the above equations) and a Gaussian function for, respectively, polystyrene and a (50/50 by weight) miscible blend of poly(methyl methacrylate) andpoly(styrene-co-acrylonitrile) [30]. Clearly, the experimental data can be described by both the theory, and also by a Gaussian function, G, of the glass transition temperature, the width...

In practice, the existence of both UCST and LCST has been established for polymer-solvent systems. About 10 years ago, Schmitt discussed UCST, LCST and combined UCST and LCST behavior in blends of poly(methyl methacrylate) with poly(styrene-co-acrylonitrile) (PMMA-PSAN), Ueda and Karasz reported the existence of UCST in chlorinated polyethylene (CPE) blends using DSC, Inoue found that elastomer blends of cis-l,4-polybutadiene and poly(styrene-co-butadiene) exhibit both UCST and LCST behavior and Cong et al. (72) observed that blends of polystyrene and carboxylated poly(2,6-dimethyl-l,4-phenylene oxide) copolymers with a degree of carboxylation between molar fraction 8% and 10% exhibit both UCST and LCST behavior. They used DSC to establish the phase diagram. 

Higher amounts of AN raise this curve to above the decomposition temperature however, at 13% or more AN the SAN copolymers are not miscible with MPC. Polystyrene forms miscible blends with poly-(vinyl methyl ether), PVME, that phase separate at quite low temperatures. Copolymerization of very small amounts of acrylic acid with styrene dramatically elevates the phase separation... 

A similarly clear and predictable contrast has been reported by Feldman et al. for a phase separated blend of polystyrene (PS) and poly(methyl methacrylate) (PMMA) imaged with gold-coated and silicon oxide coated tips in perfluorodecahn (Fig. 18) [125]. Here the contrast is dominated by the dispersive van der Waals interactions, which have been selectively amplified by... 

Polystyrene is miscible with poly(2,6-dimethylphenylene oxide), PPO. The commercial composition actually uses HIPS blended with PPO, again resulting in a very tough product. A blend of poly(vinylidene fluoride) with poly(methyl methacrylate) imparts both light stability and gasoline resistance, making it useful for coating automotive parts. 

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