Polyethylene-polystyrene blends

Figure 10.7 shows that the tensile strength is improved as polystyrene is incorporated. Data for conventional melt-blended samples (Fayt et al., 1989) are provided for comparison. We note that the ductile-to-brittle transition for our system is shifted toward much higher polystyrene content. Fayt and others have shown that conventionally prepared polyethylene/ polystyrene blends are relatively poor materials (Barentsen and Heikens, 1973 Wycisk et al., 1990). Blends of most compositions are weaker than polystyrene or polyethylene homopolymers because of the poor interfacial adhesion between the two immiscible polymers. The electron micrographs and the mechanical data for the blends described here indicate that poly-... 

Fayt, R. Jerome, R. Teyssie, P. Molecular Design of Multicomponent Polymer Systems. XIV. Control of the Mechanical Properties of Polyethylene-Polystyrene Blends by Block Copolymers. J. Polym. Sci., Part B Polym. Phys. 1989, 27, 775. 

Fayt R, Jerome R, Teyssie P (1989) Molecular design of multicomponent polymer systems. XIV Control of the mechanical properties of polyethylene-polystyrene blends by block copolymers. J Poly Sci Part B Poly Phys 27(4) 775-793... 

Figure 4. IR spectrum of polyethylene-polystyrene blend and film morphology (inset) for continuous film.

The main drawback of the elastomeric co-polymers is their rather high Tg, which is always higher than LLDPE co-polymers and increases with the styrene content, reaching values above 0°C beyond 60wt% of styrene.624 In the styrene range of 20-50 mol%, the co-polymer can be either amorphous elastomeric or crystalline. This kind of crystallinity occurs when the E-S dyad is stereoregular.625 Ethylene/styrene co-poly-mers can act as compatibilizer for polyethylene-polystyrene blends. A review on ethylene/styrene co-polymer-ization has appeared.626... 

Locke CE, Paul DR. Graft copolymer modification of polyethylene—polystyrene blends. I. Graft preparation and characterization. J Appl Polym Sci 1973 17 2597-2617. 

Polyethylene-Polystyrene Blends with Compatibilizing Agents... 

Formation of biaxially oriented films composed of polyethylene-polystyrene blends with polyethylene as the continuous phase and impact-resistant polystyrene as the reinforcing phase. Such films form tough, paperlike sheets that are impervious to water and are inherently opaque due to the existence of two phases of different refractive indexes. 

Mini-fibers have also been observed by Liang et al. [159] on melt spinning polypropylene/polyamide blends. The diameters of the dispersed polyamide 6 phase mini-fibers are tens of microns and more. This is clearly due to the large interfadal tension in this system (polypropylene/polyamide 6) as compared to polyethylene/ polystyrene blends of Min et al. (Table 1.1). 

Figure 1.24 Polyethylene mini-fibers produced from polyethylene/polystyrene blends.

Brahimi, B., Ait-Kadi, A, Ajji, A., and Fayt, R. (1991) Rheological properties of copolymer modified polyethylene/ polystyrene blends. J. Rheol., 35 (6), 1069-1091. 

Fig. 9. Comparison between model prediction and experimental findings for high density polyethylene/polystyrene blend, PE/FS = 95/5 (vol%) compounded at the screw speed N = 150 rpm with an output of Q = 10 kg/h.

Harrats Charef, Fayt Roger, Jerome Robert, and Blacher Silvia. Stabilization of a cocontinu-ous phase morphology by a tapered diblock or triblock copolymer in polystyrene-rich low-density polyethylene/polystyrene blends. J. Polym. Sci. Polym. Phys. 41 (2003) 202-216. 

The analysis of polyethylene-polystyrene blends by LCCC is presented in Figs. 20 and 21. With polar Lichrosorb as the stationary phase and decaline-cyclohexane as the mobile phase, using a column temperature of 140°C, blend separations can be accomplished. The adjustment of the critical mobile phase composition is shown in Fig. 20. As can be seen, the elution behaviour of polystyrene changes appreciably even with changes of the mobile phase composition by only 0.1 vol% [149]. This demonstrates the importance of high accuracy and reproducibility of the mixing of desired mobile phase compositions. The critical mobile phase composition corresponds to decaline-cyclohexane 95.9 4.1% by volume, indicated by the molar mass independence of the elution volume. 

Fayt R, Jerome R, Teyssie Ph (1986) Molecular design of multicomponent pol)Tner systems. XII. Direct observation of the location of a block copolymer in low-density polyethylene-polystyrene blends. J Polym Sci Polym Lett 24 25-28... 

Chen, G., Guo, S., and Li, Y. (2004) Dynamic rheological properties of high-density polyethylene/polystyrene blends extruded in the presence of ultrasonic oscillations./. Appl Polym. Scl, 92, 3153-3158. 

Agari Y, Ueda A, Nagai S (1992) Thermal conductivity of polyethylene/polystyrene blends containing SEBS block copolymer. J Appl Polym Sci 45 1957-1966... 

J. Li and B. D. Favis, Characterizing Co-continuous High Density Polyethylene/Polystyrene Blends, Polymer 42, 5047-5053 (2001). 

J. Li, B. D. Favis (2001) Characterizing co-continuous high density polyethylene/ polystyrene blends. Polymer 42,5047. 

Guo HF, Packirisamy S, Mani RS, Aronson CL, Cvozdic NV, Meier DJ (1998) Compatibi lizing effects of block copolymers in low density polyethylene/polystyrene blends. Polymer 39 2495 2505... 

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