Extraction of Banana Fibers

Preparation of Banana fibers The stems of Banana plant were taken and cut into small sizes of equal length as shown.

The small sized banana stems upper surface was peeled off which contains excess of water and impurities. These are then fixed in a machine which contains two oppositely rotating motors having needle like structure emerging out of its surface to remove the lignin and hemicellulose contained in the stem leaving behind the fibers.

After the process, we get two kind of fibers being extracted: -Straight fibers -Random fibers And again from the straight fibers we get some random fibers. For our study, we are using random fibers to reinforce the polymer to get composite and do the mechanical analysis. We analysed the fiber (random from machine and random from straight fibers) and it showed that the machine yielded fibers are little damaged as compared to random fibers from straight fibers. So random from straight fibers can work as good reinforcement and hence are used for further processing.

Chemical Treatment of Banana Fibers with NaOH Over the last two weeks we have carried several experiments on alkaline treatment of Banana fibers with different concentrations of NaOH solution and different soaking time.

Preparation of Solution: we first prepared a 0.1 and 1 Molar solution of NaOH with distilled water and soaked the 1 gram of fibers in it for 15 minutes and then washed it with water just once and kept in the heated chamber of 100*C for an hour which resulted in - one sample fried and another being a bit yellowish in color. Next we prepared the same solution of NaOH i.e. 0.1 and 1 molar solution and soaked 1 gram of fiber in it for 15 minutes and washed it several times after soaking with distilled water to get a pH of around 7(we got near to 6.7)....and then we kept the sample in heating chamber at 60*C for an hour and at 70*C for another hour and we got fibers with 0.77g(1Molar solution) and 0.89(0.1 molar solution) which looked a bit different in color.

Soaking time in 1% CH3COOH Weight after drying(grams) Initial weight of fibers = 1 gram Drying Temperature = 80*C Time of Drying = 2 hours Sl. NO. Concentration of NaOH Soaking time in NaOH Soaking time in 1% CH3COOH Weight after drying(grams) 1 2 3 4 5 6 7 8 0.1N 1N 0.03N 0.07N 30 minutes - 1 hour no CH3COOH 0.85 0.93 0.86 0.82 0.81

Sl. NO. Concentration of NaOH (W/V) Soaking time in NaOH Soaking time in 1% CH3COOH Weight after drying(grams) 9 10 11 12 1% 3% 5% 7% 1 hour 15 minutes 0.91 0.88 0.87 0.86

The most yellow brownish is the first sample we treated with NaOH and washed just once and the extreme left fiber is the 1 N treated fiber and the middle is the 0.1 N treated and extreme left is untreated banana fiber. As seen ,the lightness of fiber has decreased a bit from 0.1 to 1 N i.e. after alkylation which is due to removal of lignin and i read that bleaching would cause the change in colour from brownish to silvery white...if treated. The first sample is brownish because of presence of lignin which is not washed properly. Its been observed that the fiber we treated chemically are not fully devoid of the NaOH which is due to the improper washing or presence of NaOH inside the fiber due to penetration which in result have yielded in the damage of fibers. These fibers are hence not suitable for further usage. To make these fibers fully devoid of NaOH, we will be using Phenolphthalein indicator to see the neutralisation point to get the neutral solution of fibers which will help yield white fibers which can be further used as reinforcement. Density: A sum of ten fibers were taken from the 0.1 gram weighed fiber and their length & diameter were calculated precisely using a Vernier calliper. An average of these lengths (L) and average diameter (D) was calculated. Density = 1.35 g/cm^3 as calculated from formula, density = Mass/Volume.