New hyperbranched carbosiloxane–carbosilane polymers with aromatic units in the backbone

New hyperbranched polymers based on a carbosiloxane–carbosilane skeleton with aromatic units in the backbone have been prepared via one-pot hydrosilylation reaction using HSi(Me)2–O–CH2–C6H4–OSiMe–(CH2)4(C3H5)2 as a novel AB2 monomer. These polymers are easy to prepare, have narrow polydispersity values and present allyl groups on the surface which can be used as synthetic platforms for the introduction of different terminal groups like amine groups through hydrosilylation reactions, opening the door to functionalized polymers. The polymerization process was monitored using real-time 1H NMR spectroscopy and the resulting hyperbranched polymers were characterized using 1H NMR, 13C NMR, 29Si NMR and SEC/MALLS. The degree of branching in these polymers was determined by quantitative 29Si NMR spectroscopy and found to be very close to the theoretical value of 0.50 for AB2 systems. The hydrolytic degradation of these polymers in protic solvents has been studied by 29Si NMR.

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► New hyperbranched poly(carbosiloxane–carbosilane) systems have been prepared.
► They can be used as synthetic platforms thanks to their allyl terminal groups.
► These systems present low polydispersity and high glass-transition temperature.
► The polymers can be degraded in methanol at 80 °C or in water at room temperature.