Activated Carbons from Crosslinked Novolac Resin
Activated carbons were prepared from well-characterized Novolac resin cured with various amounts of hexamethylenetetramine (HMTA). The process consisted of curing the resin with HMTA at 200°C, carbonization in nitrogen at 600°C and gasifying the char in carbon dioxide or in steam at 900°C. The influence of the amount of HMTA used for curing on the yield and the characteristics of the activated carbon was investigated. The pore volume attained a maximum for Novolac initially cured with ca. 2 wt% HMTA. Further increase in the amount of HMTA used for curing resulted in an increase in the yield of active carbon, but the susceptibility to carbon dioxide activation decreased. Relative to carbon dioxide, the use of steam generated a narrower, but more extensive, microporosity in the char obtained from cured Novolac resin.