Compatabilization of polystyrene/polypropylene blends by styrene-butadiene block copolymers with differing polystyrene block lengths

Compatibilization efficiency of styrene–butadiene triblock copolymers in polystyrene–polypropylene blends with varying compositions

“…In previous articles, we showed that the appearance of a maximum corresponding to an ordered BC structure on the SAXS curves of compatibilized blends could have different meanings in symmetrical and asymmetrical systems. In PS–PP 4/1 blends with the addition of SB BCs, the interference maximum of a neat BC was observed when a BC with short styrene blocks was added,22, 23 and it was shown by TEM that the ordered BC was a part of the PS–PP interfacial layer. Particles of BCs with long styrene blocks were entrapped in the PS blend component and swollen by the styrene homopolymer or rearranged into micelles to such an extent that the structure of the BC was disordered and no interference maximum was observed.…”

“…Considering our experimental data20–23 and also the results of other studies,5, 8, 9, 11, 13, 16, 17 we introduced the concept of symmetrical and asymmetrical systems 24. In symmetrical systems (A–B blend and A–B BCs), good compatibilizers are BCs in which the MW of individual blocks is comparable with the MW of the corresponding homopolymers in a blend.…”

“…It is generally known that most polymers are thermodynamically immiscible, and the modification of polymer blends by interfacially active compatibilizers is necessary to obtain materials with desirable properties. In polystyrene (PS)–polyolefin blends, additive compatibilization, that is, mixture with appropriate block copolymers (BCs), appears to be the most effective procedure,1–23 although reactive compatibilization is now widespread. The addition of BCs with blocks miscible or at least compatible with the corresponding blend components reduces the interfacial tension between the constituent homopolymers and, thus, leads to their finer dispersion.…”

“…The compatibilization efficiency of a BC is given by many parameters, including the number of blocks, the molecular weight (MW) of the individual blocks, its total MW, and of course, its chemical composition with respect to the blend components. In previous studies,20–23 we investigated the compatibilization process in PS–polypropylene (PP) 4/1 blends, that is, in blends with a PS matrix with a series of BCs containing PS blocks and blocks of aliphatic hydrocarbons different from PP. The reason we used this procedure was that the synthesis of PS–PP BCs is rather expensive and another commercially available compatibilizer could be more convenient.…”

Phase morphology, thermomechanical, and crystallization behavior of uncompatibilized and PP‐g‐MAH compatibilized polypropylene/polystyrene blends

“…A considerable amount of work on compatibilizing PP and PS has been done in the past by adding block or graft compatibilizer. [2][3][4][5][6][7][8][9][10][11][12][13] In general, the compatibilizer enhances the interfacial adhesion between the phases, provides stabilization against phase coarsening leading to finer dispersion of minor phase there by decreases the interfacial tension. Another method of compatibilization is by adding reactive compatibilizer that reacts with the component polymers during the melt mixing stage to form chemical bonds between them.…”