Paper number 1041

A MODEL SIC-BASED FIBRE WITH A LOW OXYGEN CONTENT PREPARED FROM A VINYL-CONTAINING POLYCARBOSILANE PRECURSOR

Zengyong Chu1, Yongcai Song1, Yunshu Xu2 and Yibei Fu2

1Department of Materials Engineering and Applied Chemistry, National University of Defence Technology,
Changsha ,Hunan 410073, People's Republic of China
2Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Chengdu,Sichuan 610003,
People's Republic of China

Summary A model SiC-based fibre has been prepared from a vinyl-containing polycarbosilane precursor by means of an irradiation oxygen-free curing process. Cyclo-methylvinylsilazane (MVCSZ) was successfully grafted onto the molecular of a polycarbosilane (PCS) in order to enhance the PCS's irradiation curing. A vinyl content of 2.33wt% in PCS can lower its gel dose, curing dose from 10MGy, 15MGy to 0.5MGy, 5MGy, respectively. Thus obtained SiC fibre has a much lower oxygen content (3.3-6.3wt%) than an oxygen-cured Si-C-O fibre (18.9wt%), but shows a lower tensile strength at room temperature than the Si-C-O fibre because of some experimental factors. After the annealed treatment of 1600°C in nitrogen for 30min, the fibre containsß-SiC crystals (mean size 12nm) and retains a 67% tensile strength.
Keywords SiC, oxygen content, vinyl-containing polycarbosilane, cyclo-methylvinylsilazane, enhancement,electron beam, curing, pyrolysis.

Theme : Fibres ; Others

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