Structure design of novel hyperbranched polycarbosilazanes: Synthesis and characterization

Three novel hyperbranched polycarbosilazanes were synthesized via hydrosilylation reaction and characterized by FT-IR, ¹H NMR, ¹³C NMR, ²⁹Si NMR, and laser light scattering. First, one AB₄ type monomer bis(N,N-diallylamino)-methylsilane (M1) and two AB₂ type monomers (N,N-diallylamino)-dimethylsilane (M2) and N,N-bis (dimethylsilyl)-allylamine (M3) were prepared by aminolysis of MeHSiCl ₂ and Me₂HSiCl with diallylamine and allylamine. Then monomers were polymerized into hyperbranched polycarbosilazanes via hydrosilylation reaction using H₂PtCl₆ as the catalyst. The measurements indicate that α-hydrosilylation mainly occurs during the polymerization and the polymers synthesized consist of ≡Si-N-C≡ linkages with hyperbranched architectures carrying a large amount of functional vinyl or ≡Si-H end groups. The molecular weights (M̄_w) of the three polymers were found to be 13 500, 4 600, and 3 900 g · mol ^-1, respectively.