Formation of continuous pore structures in Si-C-O fibers by adjusting the melt spinning condition of a polycarbosilane - polysiloxane polymer blend

Kita, Kenichiro; Narisawa, Masaki*; Mabuchi, Hiroshi*; Ito, Masayoshi*; Sugimoto, Masaki; Yoshikawa, Masahito

The polymer blend including polycarbosilane (PCS) and 15 mass% of polyhydromethylsiloxane (H-oil) was prepared and properties of the polymer melt were investigated for clarifying the mechanisms of continuous pore formation. The fibers formed by the melt-spun of polymer blend at 578 K mainly possessed a single pore at the center of the fiber cross section. On the other hand, the fiber melt-spun at 543 K usually included multiple pores and the fibers melt-spun at 538 K included a number of tiny pores. It is proposed that the evolved hydrogen can be dissolved in the polymer melt and the desaturation process of the dissolved gas during the fiber spinning with sudden temperature reduction likely determined the size and location of pores in the fibers.