The Surface Profile and Functional Group of Bio-Plastic Composites in Variations of Ratio of Starch, Glucomannan and Carrageenan

The objectives of the study were to identify the surface profiles and functional groups of bio-plastic composites made from starch, glucomannan and carrageenan. The study used an exploratory method, which was carried out by making a mixed bio-plastic composite of starch, glucomannan and carrageenan. The obtained composites were observed surface profiles on the transverse and longitudinal sides using Scan Electron Microscope (SEM), and identified functional groups on polymers formed by using FTIR spectrometers. The results show that the profile of the bio-plastic composite surface on the longitudinal view indicates the presence of webs with air cavities. The webs and air cavities grew larger as changes in the ratio of starch, glucomannan and carrageenan compounds from the starting ratio (6: 0: 0), to (1: 2.5: 2.5). Meanwhile, in the ratio (0: 3: 3) it appears that there are pores between air cavities. The profile of the bio-plastic composite surface at the transverse position indicates one layer in the ratio of starch, glucomannan and carrageenan = (6: 0: 0) turns into two layers with the top layer forming clumps and waves, while the bottom is flat and smooth. Next turns flat and smooth at the top and starts to tear at the bottom, as the ratio changes from (6: 0: 0) until to (1: 2.5: 2.5). Meanwhile, in the ratio (0: 3: 3) clearly visible the large pores at the upper layer. The thickness of the upper layers changes with changes in starch, glucomannan and carrageenan ratios of the composite of bio-plastics. Each of the upper thickness of the composite in the ratio (6: 0: 0), (5: 0.5: 0.5), (4: 1: 1), (3: 1.5: 1.5), (2: 2: 2), ( 1 : 2.5: 2.5) and (0: 3: 3) are 379, 296, 222, 219, 217, 200, 200 ?m. Bio-plastic composites with mixed ratio of starch, glucomannan and carrageenan (6: 0: 0), (5: 0.5: 0.5), (4: 1: 1), (3: 1.5: 1.5), containing the OH, CH, CO (1: 2.5: 2.5) and (0: 3: 3) containing the OH, CH, CO, (CH2) n, C = C and C=O. Keywords: bio-plastic composite, ratio of starch, glucomannan and carrageenan, surface profile and functional group