Despite 60 years of history and a stunning success, Ti-based Ziegler−Natta catalysts for the production of isotactic polypropylene remain black-box systems, and progress still relies on trial and error. This represents a limitation in a moment when the most widely used industrial systems, containing phthalates as selective modifiers, need to be replaced because of a recent REACH ban. In view of the great complexity of the chemical and physical variables and the heavy nonlinearity of their effects, a high-/ medium-throughput approach to this catalysis is highly desirable; herein we introduce an integrated medium-throughput workflow spanning from propene polymerization to polypropylene microstructural characterization and combining a 10 2 -fold throughput intensification with quality standards equal or higher than conventional methods.

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The adsorption of small probe molecules (H2O, NH3 and EtOH) and the small model silane Me2Si(OMe)2 on (104) and (110) surfaces of α-MgCl2 have been studied using periodic DFT calculations including a classical correction (of the type f(R)/R6) for dispersion. The results reveal that donors strongly stabilize both crystal surfaces relative to the bulk solid. Moreover, coordination of two donor molecules to the four-coordinate exposed Mg atom of MgCl2 (110) causes this surface to become preferred over MgCl2 (104) surface with only a single donor per exposed Mg. However, coverage also plays an important role. The model silane preferentially adsorbs in bidentate mode on MgCl2 (110), provided that coverage is 0.5 or lower; at full coverage, there is not enough space for such an arrangement, and only a monodentate binding mode is obtained. Such coverage effects should be even more pronounced for the bulkier silanes used as external donors in real MgCl2-supported Ziegler–Natta systems, as tailored experiments seem to confirm.

The paper discusses the relationship between rheology and morphology of immiscible polypropylene (matrix))/polycarbonate (dispersed phase) blends compatibilized with novel polypropylene-polycaprolactone block and graft copolymers. Transmission electron microscopy (TEM) experiments revealed uniform droplet morphologies and a reduction of the average size of the dispersed phase upon addition of the compatibilizer. The results suggested the influence of the molecular weight distribution (MWD)/chemical composition distribution (CCD) and topology of the compatibilizer on the compatibilizing performance. Graft copolymers were found to be most effective in reducing the size of the dispersed phase, whereas the performance of block copolymers appeared to be highly dependent on the block length of PP. Small-amplitude oscillatory rheological experiments revealed an increase in elasticity at low frequencies caused by the interfacial interactions induced by the compatibilizer. The effect was quantified using the relaxation time spectrums that displayed the additional peak at longer relaxation times via Gramespacher-Meissner method. Broadband dielectric spectroscopy (BDS) revealed the influence of the copolymer architecture and molecular weight of the polypropylene blocks on the properties of the interfacial polarization, which was in line with both rheology and morphology data.