Abstract:Curing of polyalumninocarbosilane(PACS) is the key process to prepare near ̄stoichometric SiC(Al)
fibers. It is crucial to control the oxygen content of continuous PACS fibers during curing. In this workꎬa new method
has been used to predict the oxygen content of PACS fibers during curing exactly and easily. The curing process of
PACS fibers are traced by in ̄situ measurements. And a non ̄isothermal curing dynamics model has been established
with section integration. The dynamics model is solved with non ̄linear function using in ̄situ data. As a resultꎬ the
weight gains during the curing can be predicted. Polycarbosilane(PCS) fiber was cured at the same condition as com ̄
parison. It is found that:at the same conditionꎬ PACS and PCS fiber both got gel point at the Si—H reaction content
of 40%ꎬtheir gel content both reached 100% after curingꎬ when their oxygen content is 9.7wt% and 14.7wt%ꎬrespec ̄
tively.The weight gains and Si—H reaction content of PACS fiber are both lower than that of PCS fibers. The curing
dynamic equation is solved by lsqnonlin function in matlab using the in ̄situ data. It is calculated that activation energy
of PACS is 62.2 kJ/ mol. The model can predict the weight gains during curing.