Blends PS/PPE

Everaert V, Aerts L, Groeninckx G (1999) Phase morphology development in immisdble PP/(PS/PPE) blends influence of the melt-viscosity ratio and blend composition. Polymer 40 6627-6644... 

In the other PS/PVME system, the complete temperature range of interest was accessible. The typical linear behavior of In Vg° versus 1/T for PS with =17,500 g/mol was obtained between 120 C and 210 C. Thus, all blends of PS/PVME and the pure PVME were measured in this temperature range. Five different probes (acetone, ethyl acetate, cyclohexane, n-octane, and ethyl benzene) were used to get X23 As observed in the PS/PPE blends, X23 scattered depending on the probe. Because of the limited number of probes and their different chemical nature, no systematical probe dependence could be detected. Thus, the different X23 values were averaged. 

PPE is the most natural additive that upgrades performance of PS to the required level. PS/PPE blends have been used as a replacement for PS in applications where higher HDT and/or impact strength is required. These alloys are easy to foam for the manufacture of, e.g., hot water piping insulation, in automotive applications, etc. Examples of PPE/PS blends are listed in Table 1.14. 

Incorporation of a miscible resin with a lower glass transition temperature (T makes it possible to process the high T resin at temperatures well below the thermal degradation limit (e.g., PS/PPE blends). 

Fig. 2.8 The binary interaction parameters and Sy of the Simha-Somcynsky (S-S) EoS for PS/PPE blends (T range, to 330 °C ...

The semicrystalUne phase morphology and crystallinity of POM in POM/(PS/PPE) blends were studied with respect to fractionated crystallization (Everaert et al. 2003). The degree of crystallinity decreases with decreasing POM content with a visible shift from bulk to homogeneous crystallization. Analysis of WAXD reflections indicate that the decrease in is not solely due to the formation of thinner lamellae at higher degrees of undercooling. 

Table 3.28 Influence of the POM content in POM/(PS/PPE) blend systems on the final degree of crystallinity, as calculated directly from fractionated crystallization curves. Xc for POM is 54 % ...

An interesting study to determine the influence of temperature on blend free volume was carried out on PS/PPE blend [19]. Figure 27.9a clearly demonstrates... 

Figure 27.9 (a) Variation of free volume size distribution (PDF) for PS/PPE blend for different temperatures. Reproduced with permission from Ref [19] (b) Fractional free volume as a function of EPDM content in PP/EPDM blend. Reproduced with permission from Ref [23]. 

Figure 17 Delonmation response of PS/PPE blends. Left Measured in compression. Right Measured in tension.

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