PHYSICAL-PROPERTIES OF CHEMICALLY-MODIFIED WOOD CONTAINING METAL .2. INTERACTION BETWEEN MODIFIED WOOD AND METAL

Dynamic mechanical properties of carboxymethylated woods (CMWs) with various metal ions including Na+, Mg2+, Ca2+, Zn2+, Al3+, and Fe(III)3+ were measured. On the basis of results, the effects of metal-ion species and the amount of metal ions upon the molecular motions of the wood components, in particular cellulose, are discussed. For CMW, there are four dispersions at about -60-degrees-C, 20-degrees-C, 50-degrees-C, and above 200-degrees-C, being labelled alpha, beta, gamma, and delta in order of decreasing temperature. Both the beta and the gamma-dispersions, which are attributed to the motion of the carboxymethylated cellulose main-chain and that of carboxymethyl groups, respectively, are affected by variation of the metal-ion species. The peak temperature of the beta-dispersion (T-beta), which is related to the mobility of the carboxymethylated cellulose main-chain, depends on the charge (Q(c)) (the valence), the amount of metal ion (DELTA-m), and the radius (r) of metal ion, being expressed as follows: T-beta = 3.5.(Q(c)/r.DELTA-m) + 40.5.