Functional Elastomers via Sequential Selective Diene Copolymerization/Hydrophosphorylation Catalysis

Abstract

AbstractAn effective preparation of new tailor‐made macromolecular materials via the combination of two fully atom‐efficient catalytic transformations is reported. First, new isoprene‐co‐1,3,7‐octatriene [P(IP‐co‐OT)] copolymers with controlled composition (2–21 mol% triene incorporated), molecular weight (Mn=23–102,000 g mol−1) and microstructure (1,4‐cis rich) have been prepared using the homogeneous Ziegler–Natta catalyst system composed of diallylneodynium chloride, magnesium chloride, tetrahydrofuran and methylaluminoxane [Nd(allyl)2Cl(MgCl2)2(THF)4/MAO]. Next, the pendant vinyl moieties in those P(IP‐co‐OT) copolymers have been selectively transformed into phosphonate groups by hydrophosphorylation in the presence of homogeneous rhodium phosphine catalysts. The latter hydrophosphorylation reaction has been optimized in terms of catalytic activity and selectivity, to define the conditions for an effective and safe procedure that does not affect the macromolecular architecture. All polymer materials have been microstructurally analyzed by 1H, 13C, and 31P NMR spectroscopy, to diagnose the catalyst selectivities in the copolymerization and hydrophosphorylation processes.