Graft-type polyblends

The phenomenon of the phase inversion itself has been investigated by Molau (1965), who studied the graft-type polyblending of styrene with... 

Discussion of the detailed structure of the graft-type polyblend latex particle requires amplification. In the formation of the ABS type G resin, part of the AS copolymer forms a shell around the seed latex (Kato, 1968), as shown in Figure 3.6. As with other types of graft copolymers, some monomer dissolves within the seed latex. Upon polymerization, the second monomer mix phase-separates to yield the complex inner morphology observed. After coagulation, the glassy AS polymer forms the matrix, while the portion occluded within the latex particles remains within the rubber phase (Figure 3.7). 

One might speculate that the crack growth through the rubber portion could be used to help explain the greater toughness of graft-type polyblends in... 

In Figure 5 an electron micrograph of a midrange PEA (butadiene doped)/PS incompatible IPN composition is compared with a commercial graft-type polyblend, HiPS, supplied by Monsanto Company, Springfield, Mass. HiPS contains polybutadiene (stained black with osmium tetroxide) dispersed in PS. 

Surprisingly, the IPN exhibits a complex cellular structure. Similar cellular structures are evident in the polybutadiene portion of the HiPS, and in graft-type polyblends... 

Figure 5. Graft type polyblend, HiPS, (top) IPN of poly (ethyl acrylate) containing ca. 1% butacJiene monomer with polystyrene (48.8 PEA/51.2 PS), (bottom). Note similarity of cellular structures.

The grafting of side chains from other monomer types to the main chain (backbone chain) is called graft copolymerization. Physical mixtures of plastics are designated as polyblends. Table 10 illustrates these terms. 

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