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A divergent hydrosilation/Grignard-reaction sequence, followed by hydroboration of the allyl end groups was employed to prepare a series of novel dendritic carbosilane polyols. Dendrimers with 4, 12, 36, and 108 hydroxyl end groups have been prepared. The hydroboration reactions were monitored by -NMR and MALDI-TOF and were quantitative in all cases. Using MALDI-TOF, the carbosilane dendrimers as well as the novel dendritic polyols have been characterized directly with respect to polydispersity. Whereas G2-OH consisted of mainly two species, the desired 36-ol (80%) and the 34-ol, G3-OH consisted of polyols with 92-108 hydroxyl groups. The dendritic polyols possess low glass transition temperatures (233-241 K) and thus constitute flexible polyols without polar interactions between the dendrons. The molecules appear suitable as chemically stable, flexible molecular scaffolds for the construction of unusual supermolecular architectures.

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Fused filament fabrication (FFF) of polyethylene (PE) reactor blends containing high amounts of nanophaseseparated disentangled ultrahigh molar mass polyethylene (UHMWPE) generates self-reinforced all-PE composites that exhibit superior mechanical properties. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and small/ wide-angle X-ray scattering (SAXS/WAXS) analyses reveal that flow-induced crystallization accounts for the in situ formation of fiberlike extended-chain one-dimensional (1D) nanostructures that nucleate high-density PE (HDPE) crystallization, resulting in "shish-kebab" structures as a reinforcing phase. Both the orientation and the content of the 1D nanostructures are controlled by varying the three-dimensional (3D) printing parameters like nozzle temperature, printing pathway, and printing speed. Compared with conventional HDPE, this selfreinforcement simultaneously improves the stiffness (+100%), tensile strength (+200%), and impact strength (+230%) of the material. For the first time, the limited scope of conventional melt processing is advanced and 3D printing, guided by computer design, is applied to enable the fabrication of both unidirectional and digitally tuned multidirectional all-PE composites with quasiisotropic properties as a function of the 3D printing pathway.