Polystyrene polybutadiene blend

The properties of such heterogeneous polystyrene/polybutadiene blends mainly depend on the following parameters ... 

Preparation of a Polystyrene/Polybutadiene-Blend (High Impact Polystyrene, HIPS) by Polymerization of Styrene in the Presence of Polybutadiene... 

It is particularly important for certain mechanical vulcanizate properties, as stress relaxation, creep and compression set, that all the polymer molec in the vulcanizate should become bound into molecular networks of inc nite size during the vulcanization process. The results of Shundo et al. [ shown in Figure 15.7, demonstrate clearly that much more polymeric n" rial can be extracted by suitable oiganic solvents from vulcanizates der from polystyrene-polybutadiene blends than from vulcanizates derived from copolymers. These results indicate clearly the presence of non-network-bo polymer in the vulcanizates derived from the homopolymer blends. 

Both component polymers form separate, but intermingled phases (Figure 1). Since polystyrene and polyethylene are immiscible, simple compounding gives very brittle products. Addition of a compatibilizer (e.g., RCM1 or RCM 2) makes it possible to obtain useful blends. Morphology of polystyrene/polybutadiene blends can be seen from Figures 5 and 6 in Polystyrol description. 

Kramer G, Griepentrog M, Bonaccurso E, CappeUa B. Study of morphology and mechanical properties of polystyrene -polybutadiene blends with nanometre resolution nsing AFM and 44. force-distance curves. Euro Polym J 2014 55 123. 

Figure 5.34. Scanning electron micrography of a polystyrene-polybutadiene blend in absence of a compatibilizing agent. [Courtesy of BASF Cy (Ludwigshaffen Germany).]...

The effect of pressure on phase diagrams has also been investigated and simulated. The results of one experiment are shown in Figure 8 for oligomeric polystyrene/polybutadiene blends. The effect of pressure is selectively dependent on the volume change on mixing and the fact that the theory explains the data relatively well supports the conclusion that the free volume effects are adequately accounted for. 

The substantial work on polystyrene/polybutadiene and polystyrene/ polyisoprene blends and diblock and triblock copolymer systems has lead to a general understanding of the nature of phase separation in regular block copolymer systems (5,6). The additional complexities of multiblocks with variable block length as well as possible hard- and/or soft-phase crystallinity makes the morphological characterization of polyurethane systems a challenge. 

PS blends with EPDM were compatibilized by addition of either SB (polystyrene/polybutadiene di-block copolymer) or SEP (polystyrene/ethylene propylene di-block copolymer) and were blended in a corotating twin-screw extruder T = 200°C (Table 11.9). The strands were quenched and pelletized. Some of the pellets were injection-molded (200°C) into 4 mm-thick specimens and irradiated to 50 kGy (3-MeV electron accelerator). Another part of the pellets was similarly irradiated and then injection-molded. The samples for notched Izod impact testing (ASTM D256) were annealed for 24 h at 80°C, or were left at RT for 3 weeks, before testing [van Gisbergen et al., 1990,1991b]. 

Mechanism of the chemical bonding between the benzene ring of polystyrene (PS) and the double bond of the polybutadiene. (From Martmez-Barrera, G., Studies on the rubber phase stability in gamma irradiated polystyrene-SBR blends by using FT-IR and Raman spectroscopy. Radiation Physics and Chemistry 2004,69,155-162. With permission.)... 

An elastomer which upon heating turns into regularly behaving linear polymer. Polystyrene-polybutadiene block copolymers, polypropylene blends with ethylene-propylene-diene terpolymer provide examples. 

Styroplus Polystyrene, PS, blends with polybutadiene, PB BASF Plastics... 

Mechanical or Physical Blends, While a blend is a physical mixture rather than a definite reacted species, many block and graft polymers contain greater or lesser quantities of homopolymer. In particular, the only slightly grafted HiPS and ABS materials are usually listed together with the polybutadiene/polystyrene mechanical blends. It is convenient to introduce a special designation for blended materials A simple example is... 

Poly(ethyl methacrylate) + poly(vinylidine fluoride) Copoly(raethyl methacrylate-methyl acrylate) blends Copoly(methyl methacrylate-ethyl acrylate) blends Copoly(methyl methacrylate-butyl acrylate) blends Copoiy(mefhyl methacrylate-butyl methacrylate) blends Polystyrene + polybutadiene Polystyrene + polyisoprene Polystyrene + poly(vinyl methyl ether)... 

Additional examples of the application of the Flory EOS to polymer blends include polystyrene/poly(vinyl methyl ether) [15,20,21], oligomeric polystyrene/polybutadiene [22], ethylene-vinyl acetate/chlorinated polyethylene [23], poly(e-caprolactone)/PVC [24], poly-(ether sulfone)/poly(ethylene oxide) [25]. 

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