Reciclagem química do jornal para a produção de membranas de acetato de celulose pelo processo de acetilação homogêneo

Abstract

In the present work, the chemical recycling of waste newspaper it was done through the homogeneous acetylation process applyed to original and purifyed materials. This materials were characterized by FTIR and TGA. To the sythesis, it was used 48 hours of acetylation to original newspaper (AC48) and 24 hours to purifyed newspaper (AC24). Membranes from this acetyladed materials were produced. The powders of acetatates were characterized by FTIR, and their membranes were characterized by DSC, TGA and water vapor flux through by the Payne s cup technique. Membrane of comemercial cellulose acetate from Rhodia was prepared and submited to the same experiments that membranes obtained by newspaper acetylation. The purifyed newspaper FTIR spectra presented a reduction of the band s intensity attibuted to the lignin when it was compared with unpurifyed newspaper spectra. The TGA thermograms, when compared, shown that the original and the purifyed newspaper have a similar thermal stability, and the original newspaper showed the highest solid residue. The powders espectrum s acetylated samples shown characteristics bands of cellulose esters around 1750 e 1230 cm-1, attributed to acetate groups and also a reduction of the band s intensity at around 3460 cm-1, which is attributed to the stretching of the cellulosic OH group. The degree of substitution (DS) obtained to the samples AC48 and AC24 was 1,98 ± 0,02 and 2,79 ± 0,02 respectively. The enthalpy of fusion present in DSC measures were 2,75, 16,1 and 8,4 J.g-1 of commercial, AC48 and AC24 membranes respectively. TGA experiments of the membranes, under the nitrogen atmosphere, shown that the commercial material has great thermal stability and the lowest solid residue (3%). The solid residue of AC24 and AC48 membranes were 14,74 and 21,21% respectively. The water flux it was normalized. The water flux values were compared with the nanofiltration commercial membrane flux, SG from Osmonix. The water flux values for the recycled materials membranes were lower than the commercial membrane and commercial cellulose acetate membrane from Rhodia.