PSI - Issue 27

Sakuri Sakuri et al. / Procedia Structural Integrity 27 (2020) 85–92 Sakuri et al. / Structural Integrity Procedia 00 (2020) 000 – 000

88 4

AI 9 and above (Figs. 1.d - 1.f) shows CF damage in (-OH) hydroxyl and fibril bonds. The loss of hydroxyl bonds results in decreased fiber strength. 3.2. Thermogravimetric Analysis (TGA) TGA testing used Perkin Elmer Pyris Diamond TGA 6 Analyzer (FPMIPA Laboratory of Universitas Sebelas Maret, Surakarta, Indonesia) to test the stability of CF samples with untreated and treatedvariations. All samples were scanned at room temperature, which increased from 30 to 600 °C at a speed of 100 o C / min. TGA tests are carried out in a nitrogen environment.

120

100

(a)

80

(b)

(a) = UE UNUntreatedun (b) = AI 3 (c) = AI 6

(c)

60

(d)

(b)

(d) = AI 9

(e)

(e) = AI 12

(f)

40

(f) = AI 15

Weight Loss ( %)

20

0

0

100

200

300

400

500

Temperature ( o C )

Fig. 2. Thermogravimetric analysis result.

The yield curve for thermogravimetric analysis (TGA) for CF without treatment was shown in Fig. 2. CF without treatment seems to lose weight 5.7% at temperatures below 100 °C related to water evaporation. The alkali treatment shows a smaller decrease. This phenomenon shows the fiber with the treated made the fiber more hydrophilic. Temperature decomposition from the EU was obtained at 210 °C with a weight reduction of 5.9%. After alkaline, the initial temperature decomposition shift was higher, 250 °C. This increase was due to the removal of amorphous elements that have a value more sensitive to heat than the crystal element. (Singha and Rana, 2010). Untreated fibers at a temperature of 300 °C experienced a weight loss of 45%. Meanwhile, the alkali treatment showed the peak weight loss at 348 °C for AI 3 and 352 °C for AI 9. This result was closely related to the removal of most of the material amorphous Primary thermal decomposition of cellulose material occurs between 200 to 400 o C (Fisher et al., 2002). Initial decay of cellulose components occurs in the early amorphous area (Mostashari and Fallah, 2007), and increasing the temperature of the disintegration of the treated fiber has a considerable effect on the thermal degradation behavior of the fibers promoting. Thermal degradation CF thermal stability increases due to the chemical degradation of hemicellulose, lignin, and silica parts during alkali treatment. An increase in the thermal stability of fibers treated with alkali is also reported (Bismarck et al., 2001). Weight reduction from various treatments, without 68% treatment, for AI 3 by 70%, and AI 6 by 75%. Untreated fiber decreases at a lower rate because of the presence of unstable thermal fiber constituents, such as hemicellulose and ash, whereas the treated fibers were more stable because of these constituents (Ray and Sarkar, 2001). It was reported that in cellulose fibers, lignin is degraded at temperatures around 200 °C while other polysaccharides such as cellulose will be degraded higher. (Aziz and Ansel, 2001). There is a slight difference between the amounts of residue left after 500 °C. The results show that there is no significant difference from the residues obtained; alkaline treatment residues are less than those that untreated.