Synthesis and Degree of Branching of Epoxy-Terminated Hyperbranched Polysiloxysilane

Hyperbranched polysiloxysilane (HBPS) with terminal vinyl groups P1 was synthesized by self-condensation reaction using platinum-catalyzed hydrosilylation of 1,1,3,5,5-pentamethyl-1,5-divinyltrisiloxane. A number-average molecular weight ( M n ) was 5400 with a polydispersity index of 1.49. End-functionalization of the terminal vinyl groups was carried out by epoxidation with 3-chloroperoxybenzoic acid to afford epoxy-terminated HBPS P2 . The polymers obtained were characterized by IR, 1 H, 13 C, 29 Si NMR spectroscopy. The degree of branching of HBPS was estimated as 0.57 in comparison of 29 Si NMR spectra of P2 and model compounds. The glass transition temperatures ( T g ) of P1 and P2 were observed at −97 °C and −77 °C, respectively. The 10% weight loss temperatures ( T 10 ) of P1 and P2 were over 440 °C in nitrogen.