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The octavinyl polyhedral oligomeric silsesquioxane (POSS) grafted polypropylene (PP) was first prepared by reactive blending. The structure and properties of physical blending and reactive blending composites of PP/POSS were investigated by wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA). WAXD analysis shows that the POSS in the reactive blending composites has better compatibility with PP than in the physical blending composites. The β-form crystalline hence disappears even the non-reactive POSS can act as an effective β-nucleating agents. DSC analysis shows the reactive blending composites have higher crystalline temperature while POSS in the physical blending composites have little effect on the crystalline temperature. The modulus of reactive blending composites increases in the presence of POSS, while that of the physical blending composites decreases with increasing POSS content.

Carbon black (CB)-filled immisicible thermoplastic/thermosetting polymer blends consisting of polypropylene (PP) and Novolac resin were reported in this paper. The PP/Novolac/CB blends with varied compositions and different processing sequences were prepared by melt-mixing method. The CB distribution, conductive mechanism and the relationship between morphology and electrical properties of the PP/Novolac/CB blends were investigated. Scanning electron microscopy (SEM), optical microscopy and extraction experiment results showed that in PP/Novolac blends CB particles preferentially localized in the Novolac phase, indicating CB has a good affinity with Novolac resin. The incorporation of CB changed the spherical particles of the dispersed Novolac phase into elongated structure. With increasing Novolac content, the elongation deformation of Novolac phase became more obvious and eventually the blends developed into co-continuous structure, which form double percolation and decrease the percolation threshold. When CB was initially blended with PP and followed by the addition of Novolac resin, the partial migration of CB from PP to the Novolac phase was possibly occurred. The addition of Novolac to PP evidently increases the storage modulus G ′, loss modulus G ″ and complex viscosity η ∗ . The addition of CB to PP/Novolac blends further increase η ∗ , and it increases with increasing CB loading, which was related to the change of composite morphology.