Sintesa dan Karakterisasi Biokomposit Poly(L-Lactid Acid)/Cellulose Acetate dan Aplikasinya sebagai Adsorben Bead

Abstract

Biocomposite materials comprised of poly(L-lactic acid) (PLLA) and cellulose acetate (CA) were prepared
through solvent blending technique. The obtained biocomposite films were characterized by using dynamic
mechanical analysis (DMA) and thermogravimetric analysis (TGA). The biocomposites were then applied as
adsorbent bead for dye separation. The properties and adsorption performance of the biocomposite beads
were also observed in term of morphology, surface area and adsorption capacity. The composition of
PLLA/CA in weight ratio was varied: 100/0; 75/25; 50/50; 25/75; 0/100. The dye used in this research for
adsorption analysis was methylene blue (MB). The MB adsorption was done in two pH conditions which are
neutral and base (pH=10) conditions. The mechanical properties of biocomposites PLLA/CA films showed
the slightly decrease in tensile strength after the addition of CA until 50 wt% and then increased again for
higher CA content. However, the young modulus continuously increased with CA content. The elongation at
break of biocomposite PLLA/CA films showed higher value of elongation at break compared to the pristine
PLLA and CA. On the other hand, the thermal stability of biocomposites increased with the increasing of CA
content compared to that of pristine PLLA. The increase in thermal stability was caused by the specific
property of CA which is high thermal resistant. For its application, the beads could only be obtained from
the biocomposite with higher CA composition, PLLA/CA (25/75) and (0/100). The morphology of PLLA/CA
beads showed spherical shape with porous structure on their surface. Adsorption performance measurement
showed that the adsorption capacity and % removal of the PLLA/CA (25/75) bead increase compared to the
pure CA bead.