PS/PMMA blends

Comparison of etch rates (pm/pulse) for various PS-PMMA blends with those for their constituent homopolymers (from Cole et al ). The number in parentheses indicates the ratio of the measured rate of die blend to a predicted rate based on a simple rule of mixtures relationship. 

Dynamic mechanical properties were measured on some PS/PMMA blends, using a Rheovibron model DDV-II system previously described (13). These measurements are a sensitive indicator of phase separation and can be used to obtain semiquantitative information about phase morphology as well (14). 

To simulate the toner-silica interactions, PS/PMMA blends were used as a model for polystyrene/acrylic toners. Silicon tips modified either with HMDS or with PDMS were applied to model surface-treated silica particles. The Pulsed Force Mode images of PS/PMMA films displayed... 

Fig. 2. Pulsed Force Mode images of PS/PMMA blend show no distinct changes in the tcqpography (upper row) when silylated tips are used but a clear dqiendence on the adhesive contrast (lower row). With a pure silicon tip (A), the elevated areas show higher adhesion after silylation, contrast is reversed. The HMDS-modified tip (B) shows a lower maximum force than the PDMS-treated tip (C).

Ton-That C, Shard AG, Teare DOH, et al. XPS and AFM surface studies of solvent-cast PS/ PMMA blends. Polymer 2001 42(3) 1121-1129. 

The method is particularly easy to use if either one of the two polymers is iso-refractive with the solvent, or if the polymers have equal contrast [Pinder, 1997]. The method was successfully used to measure X23 for PS/PMMA blends of different MW. 

In contrast to measurements of the interfacial tension coefficient, only few measurements of the interphase thickness have been reported [Wlochowicz and Janicki, 1989 Janicki et al, 1986]. For example, domain boundary thickness were measured in PS/PMMA blends [Foster et al, 1990 Fernandez et al, 1988 Russel et al, 1991 Perrin and Prud homme, 1994]. Generally, values in the range of 2-6 nm were reported for the interface thickness. 

Figure 7.26. Concentration dependence of shear viscosity of PS/PMMA blends. Points are experimental [Lyngaae-Jprgensen, 1983], while the lines were computed from Equation 7.125.

Figure 7.30. Concentration dependence of zero shear viscosity of PS/PMMA blends at 180 and 210°C. Points are experimental [Valenza et al., 1991], solid lines are computed from Eq 7.125.

The PS/PMMA blends containing 100, 90 and 70 wt% PS showed increasing radiation sensitivity. These systems could be considered dispersions of PMMA in a PS matrix, where the flexural strength is determined by the matrix. Addition of PMMA did not greatly reduce the radiation resistance of PS and addition of 10 wt% PS did not increase the radiation resistance of PMMA. In the blends, a protective effect of higher concentrations of PS was observed — this effect depended on the MW of the component polymers. 

Torikai et al. [1994] compared the effects of gamma irradiation of films of PS/PMMA blends and PS-PMMA copolymer (co-PS-PMMA) (Table 11.9). Polymer films were cast from methylene chloride solutions and were dried under vacuum. Based on the UV and FTIR spectroscopy, and viscosity measurements, Torikai et al. [1994] concluded that whereas the presence of PS in the copolymer provided protection against radiation-induced degradation to the PMMA units, similar... 

Katare et al. [1994] studied the microhardness of PS/PMMA blends, made from solutions of the two in benzene, and concluded that the increase in the microhardness of the blends on irradiation (Table 11.9) was due to crosslinking of PMMA. Since PMMA is known to degrade on irradiation (see Section 11.3, and the authors Introduction) the results obtained by these authors seem to require alternate explanation. 

Fig. 25, Chromatograms of PS-PMMA blends at the critical point of PS stationary phase RP-18 mobile phase THF-water 88.8 11.2 v/v...

Particle diameter versus annealing time at 180°C for (a) 70/30 polystyrene/polymethyl methacrylate (PS/PMMA) bend without addition of a copolymer and (b) 70/30 PS/PMMA blend with 5% PS-b-PMMA copolymer. (Reproduced from Macosko, C. W., Guegan, R, Khandpur, A. K., Nakayama, A., Marechal, P., and Inoue, T. 19%. Compatibitizers for melt blending Premade block copolymers. Macromolecules 29 5590-5598 with permission from American Chemical Society.)... 

Li, X., Han, Y., An, L. Annealing effects on the surface morphologies of thin PS/PMMA blend films with different film thickness. Appl. Surf Sci. 230(1-4), 115-124 (2004)... 

Ton-That, C., Shard, A.G., Daley, R., Bradley, R.H. Effects of annealing on the5 surface composition and morphology of PS/PMMA blend. Macromolecules 33(22), 8453-8459 (2000)... 

Vapor sorption of PS/poly(a-methylstyrene) gave X23 = 0.504, varying with T and polymer concentration, indicating that this system is immiscible with UCST > 100 °C (Saeki et al. 1981). Light-scattering measurements of ternary systems, polymer(l)/polymer(2)/solvent(3), were also successfully used to determine polymer/polymer interaction parameters, Zi2(0)- The method is particularly easy to use either if one of the two polymers is iso-refractive with the solvent or if the polymers have equal contrast (Pinder 1997). The method was successfully used to measure X12 for PS/PMMA blends of different M ,. 

Fig. 8.10 Phase diagrams at various shear rates of PS/PMMA blend...

---