Manufacturing and Characterization of Molecular Sieving Carbon from Phenol-urea-formaldehyde Composite Resin

Molecular sieving carbon (MSC) is a special activated carbon possessing uniform fine pores of several angstroms, and exhibiting adsorption selectivity due to the size and the shape of the adsorbate molecule. In the current research, it is reported that the char manufactured from the phenolic resin composite synthesized with addition of urea resin has a molecular sieving ability. In the present study, the char was manufactured from the phenol-urea-formaldehyde composite resin varying in the mixing ratio of the component resins, and the resultant molecular sieving ability was evaluated on the basis of the adsorption isotherm of various gases on the char. Moreover, the factor affecting the gas separation performance was investigated in relation to the pore structure and the crystallographic structure of the char. As a result, pore structure of the char with a high molecular sieving performance was understood to have very sharp pore size distribution in a range chose to the size of the gas molecule to be sieved. Moreover, by changing the mixing ratio of the component resins and carbonization temperature in a range from 1073K to 1273K, it was confirmed that the average in-plane crystallite width (La) significantly changes horizontally while the average number of laminated layers and the average out-of-plane crystallite thickness (Lc) hardly changes.