Preparation of an activated carbon artifact: factors influencing strength when using a thermoplastic polymer as binder

An activated carbon artifact was prepared through mixing, moulding, curing and carbonizing, using polyvinylbutyral resin (PVB) as the binder, dibutyl phthalate (DBP) as a plasticizing agent and isocyanuric acid ester as a cro ss-linking agent to clarify influential factors on its strength. Preparatio n conditions such as moulding pressure, temperature and time of curing, car bonization and the amount of cross-linking agent were varied to find their influences on the strength of the resultant form. The form was observed und er SEM of wide scope to find correlations between its morphology and streng th. The closed packing of the activated carbon filler and the plastic binde r was always favorable to develop the strength of the form. The curing exte nt of PVB, which was influenced by curing atmosphere, temperature and time, and cross-linking agent, was found to govern the strength of the forms. Ai r or oxygen is very essential for the curing. The optimum temperature was f ound to be 200 degreesC and longer curing time is beneficial to improve the strength. The cross-linking agent improved the strength of the form up to 7000 kPa through accelerating the cross-linkage of PVB resin. Sufficient cu ring allows the rapid heating up to 10 degreesC/min for the development of the strength by maintaining the shape of the form. The thermoplastic powder s are highly dispersed onto the surface of activated carbons and are cured sufficiently there to adhere the activated carbon grains. Sufficient curing stabilizes the thermoplastic polymer to be thermosetting, anchoring the gr ains through the carbon bond for higher strength of the carbonized form. PV B resin is cured into heat-resisting cross-linked chains through oxidative condensation onto the activated carbon surface where the oxygen functional groups appear to play important roles in the curing. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.