An outstanding heat-resistant hydroxyl boron-silicone oil with hyperconjugation action in backbone

A high heat-resistant hydroxyl boron-silicone vinylidene oil (HBSVO) was synthesized by copolymerizing hydroxyl polyborosiloxane oil (HPBSO) prepolymer with fumaryl chloride. The temperature at 5% mass loss (T (5)), 10% mass loss (T (10)), and maximum decomposition rate (T (max)) of HBSVO was 515, 550, and 600 A degrees C, respectively. The structure -Si-O-B-O-C(=O)-CH=CH-C(=O)- in the backbone of HBSVO might cause a tendency to form a five-member ring structure by hyperconjugation action between boron atom and vinylidene groups. The hyperconjugation action, which improved the heat-resistant and hydrolysis-resistant properties of HBSVO, was confirmed by UV spectroscopy, B-11-NMR, and H-1-NMR. The chemical moieties (-Si-O-B-O-C(=O)-CH=CH-C(=O)-) were also identified by Fourier transform infrared (FT-IR) and Si-29-NMR (CDCl3) spectroscopies.