SAN/PMMA

Attractive interactions are also the reason for the self-assembly of PS-fo-PB-fo-PMMA at the interface of poly(styrene-co-acrylonitrile), SAN, and poly(2,6-dimethylphenylene ether), PPE. In this blend, PS and PPE are miscible on one side and PMMA and SAN are miscible on the other one, with negative / parameters. This blend, in which the rubbery domain is located at the interface between SAN/PMMA and PPE/PS, was originally prepared by coprecipitation of all components from a common solution [195]. From a processing point of view, in this system the difficulty was to get the dispersion of PPE in SAN via melt mixing of SAN, PPE and the triblock terpolymer. 

If such a powder blend is fused on a hot plate after suction and drying, a turbid two-phase melt is formed with incompatible components (e.g., PS/PMMA), whereas a clear mixed melt is formed from compatible components (PS/PPE or SAN/PMMA). 

The solubility of carbon dioxide at the selected saturation conditions of 5 MPa and 40°C, is shown in Table 1. Both the uncompatibilized and the compatibilized PPE/SAN blends absorb similarly high amounts of carbon dioxide in the range of 100, mgg-1. However, in contrast to one-phase systems, the solubility data of the overall multiphase blend is not sufficient to describe the system, but the content of carbon dioxide in each blend phases needs to be considered. In the case of PPE/SAN blends compatibilized by the SBM triblock terpolymers, one can distinguish three distinct phases, when neglecting interfacial concentration gradients (idealized case) (1) the PPE phase intimately mixed with the PS block, (2) the SAN phase mixed with the PMMA block, and (3) the PB phase located at the interface between PPE/PS and SAN/PMMA. 

For miscible blend phases, these parameters need to be described as a function of the blend composition. In a first approach to describe the behavior of the present PPE/PS and SAN/PMMA phases, these phases will be regarded as ideal, homogeneously mixed blends. It appears reasonable to assume that the heat capacity, the molar mass of the repeat unit, as well as the weight content of carbon dioxide scale linearly with the weight content of the respective blend phase. Moreover, a constant value of the lattice coordination number for PPE/PS and for SAN/PMMA can be anticipated. Thus, the glass transition temperature of the gas-saturated PPE/SAN/SBM blend can be predicted as a function of the blend composition (Fig. 17). Obviously, both the compatibilization by SBM triblock terpolymers and the plasticizing effect of the absorbed carbon dioxide help to reduce the difference in glass transition temperature between PPE and SAN. 

However, as cell growth proceeds, the physical as well as chemical constraints of the triblock terpolymers inhibit pronounced growth within the PB phase. Instead, the nucleated cells tend to grow into the SAN/PMMA phase. As the PPE/PS phase still stores a significant amount of carbon dioxide, the blowing agent is subsequently transported along the interface towards the foam cells. Apparently the PPE/PS phase still acts similar to a solid phase. 

SBM content (wt%) Glass transition temperature of PPE/PS (°C) Glass transition temperature of SAN/PMMA (°C) ... 

MAJOR POLYMER APPLICATIONS aUcyd, acrylics, polyurethanes, epoxy, PP, PA, LCP, PET, SAN, PMMA, fluorombber, phenoxy... 

These parameters have been found useful to predict miscibility of blends containing one component whose structure systematically varied, e.g., polyesters with either halogenated polymers or Phenoxy [Prud homme, 1982 Harris et al, 1983 Woo ei al, 1985 Woo et al, 1986], polyamide blends [Ellis, 1989], ternary blends [Shah et al, 1986] and other systems, viz. SAN/ PMMA, SAN/PC, polyethyloxazoline/polyester, PPE with a mixture of P(oClS) and P(pClS), PC/PCL/Phenoxy, and many more. 

SAN/PMMA PMMA is immiscible with either PS or PAN. Miscibility with SAN having AN = 5.7-38.7 wt%, at T = 140-170°C. Interfacial thickness data. LCST McMaster, 1975 McBrieity etal., 1978 Higashita et al., 1995... 

Table 14.12. Enthalpy relaxation in blends of PS/PPE and SAN/PMMA analyzed using the Hodge model (N-parameters)...

As long as the measuring time is short compared with the relaxation or retardation times the aging process can be studied effectively, and short-term stress-relaxation measurements have been carried out on blends of SAN/PMMA and PS/PPE [Ho et al., 1991]. Eq 14.13 was used to fit the data and the authors found that x could be expressed by ... 

Generally all thermoplastic polymers can be processed by thermoforming, but there are significant differences regarding process windows. Amorphous polymers show a wider softening temperature range than semi-crystalline polymers, which results in a wider process window and a more stable process [7]. For this reason only few semi-crystalline polymers are used in thermoforming, for example PP, PE, C-PET and polyester. The most commonly used amorphous polymers are PVC, PS, ABS, SAN, PMMA, PC and A-PET. 

Intermediates consist of ABS, SAN, PMMA (acrylics) and engineering derivatives of cellulose like CAB (cellulose acetate butyrate), their relative price reaching around 2 (on the basis of PE as unity). Some consider these polymers at the low range of engineering polymers, due to their physical properties. (PP is frequently sorted as such.)... 

Solvent blue 7. See p-Phenylazoaniline Solvent blue 8. See Basic blue 9 Solvent blue 18. See 1,4,5,8-Tetraaminoanthraquinone Solvent blue 97 CAS 61969-44-6 Classification Anthraquinone Properties Dens. 1.18g/cm3 m.p. 200°C Uses Colorant in both transparent and opaque dyeing of PS, SAN, PMMA, PC, rigid PVC, CA and CAB colorant in opaque dyeing of SB,... 

Properties Orange-red powd. m.p. 230-232 Uses Colorant for transparent or nontransparent dyeing of PC, PS, SAN, PMMA, UPVC, CA and CAB, and coloring of transparent paint and polyester before spinning... 

Figure 3.5. dCp/dT versus temperature data for different annealing times at 80°C for a SAN/PMMA blend (50/50). 

Figures 3.10 and 3.11 show the changes of ACp for PS [31] and for a 50/50 SAN/PMMA blend at different annealing temperatmes and for different annealing times, respectively. For the PS sample, the annealing time was 60 min. The results show that the values for PS are almost constant...

Figure 3.11. ACp versus annealing time at 80°C for an SAN/PMMA blend (50/50 wt/wt).

Bousmina, M., Lavoie, A., and Riedl, B. (2002) Phase segregation in SAN/PMMA blends probed by rheology, microscopy and inverse gas chromatography... 

Figure 2.2. Experimental cloud point curve (SAN/PMMA). The region below the line is homogeneous. Phase separation takes place above the line. ...

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