The Effect of Incorporation of POSS Units on Polymer Blend Compatibility

摘要

In this work, the compatibility of poly(methylmethacrylate) (PMMA) and polystyrene (PS) polymers withtheir polyhedral oligomeric silsesquioxane (POSS) copoly-mers combined by solution blending is investigated, to deter-mine the effect of incorporation of the POSS unit on polymercompatibility. The morphology of these tethered POSScopolymer/polymer blends was studied by electron micros-copy, thermal analysis, and density. Although the basic PS/PMMA blend was clearly immiscible, it was also found thatthe incorporation of POSS into the PS chain led to incompati-bility when the POSScoPS copolymer was blended with PShomopolymer. However, conversely, in the case where thePOSS moiety was included as part of a copolymer withPMMA, the copolymer was miscible with the PMMA homo-polymer. The presence of isobutyl units on the corners ofPOSS cage is clearly sufficient to encourage miscibility withPMMA. Interestingly, blends of the two different POSScopolymers led to an immiscible structure, despite having thecommon POSS units, the interactions between the POSS moi-eties clearly not being sufficient to drive compatibility. ThePOSS copolymers have also been used as interfacial agents inimmiscible PS and PMMA blend, and it has been found thatthe appearance of the interface bonding is improved,although the phase morphology is only slightly changed.