ISBN : 978-602-17761-0-0
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in various concentrations 1, 2, 4 and 6 of alkali NaOH for puriication process, continued
with the drying process of bacterial cellulose gel to get dried cellulose and inally doing acetylation to
obtain cellulose acetate. And then the characterization was carried out, measuring such quantities as moisture
content, ash content, the levels of cellulose-α, acetyl content and yield values in compliance with the
procedural guidelines outlined in the ASTM D 871-96 and SNI 14-0444-1989 references.
1. Making Nata De Coco.
A total of 5 ive liters of iltered coconut water was boiled, added by sugar, 10 of the volume of
coconut water 500 g. Acetic acid solution was put until the solution attains a pH value of 3, then 0.5
wv.ammonium sulfate was added The solution was poured into rectangle trays 20x10x5 cm, then
the acetobacter xylinum bacteria was incubated
with quantity as much as 10 for ten days at room temperature to get nata de coco gel.
2. Puriication of bacterial cellulose by immersion in a base NaOH solution.
The nata de coco gel was boiled for 15 minutes, and then immersed with various concentrations of
1-, 2-, 4- and 6 NaOH at room temperature for 24 hours, followed by neutralization with acetic acid.
To obtain dried bacterial cellulose, the Nata De Coco from the process mentioned above was washed
several times with water, then pressed and dried by sun drying. The dry cellulose was milled and the cellulose
was iltered to obtain a 30 mesh size. Characterization was performed to determine the moisture content,
ash content and levels of cellulose with a reference to ASTM D 871-96 and SNI 14-0444-1989.
3. Preparation of Cellulose Acetate.
Cellulose powder 3 g was transferred into 24 mL of glacial acetic acid for 60 min at 40 °C, then
as much as 10 mL anhydrate acetate was added and stirred with a shaker for 20 hours. The acetylation
process was carried out, in which 15 mL of acetic acid
and 1 mL of glacial sulfuric acid were irst added, and the whole mixture was stirred at 40°C for 45 minutes.
Finally, another 10 mL of anhydrate acetate was added and stirred for 20 hours at 40
o
C. The hydrolysis process was performed, in which 5 mL of distilled
water and 10 mL of acetic acid were added, stirred for 20 h at 40 °C in a waterbath shaker.
In order to obtain precipitates of cellulose acetate, the hydrolysis end-product was washed with water
and iltered. The iltration product was dried at 50 °C for 6 hours. The characterization of moisture content,
ash content and acetic levels ASTM D 871-96 and the levels of alpha cellulose and sucrose content SNI
14-0444-1989 are then carried out on the sample.
B. Characterization
Characterization of moisture content, ash content and acetyl content ASTM D 871-96 and the levels of
cellulose-α and sucrose content SNI 14-0444-1989 was carried out by the following methods:
1. Water content ASTM D 871-96
Aluminum bowls were dried at 105 °C for 2 hours, then cooled in a desiccator and weighed on the balance.
An amount of 1 g A cellulose sample was weighed in an aluminum cup of known weight and then heated in
an oven at 105
o
C for 2 hours. Cooled in a desiccator and weighed until the weight remained constant B.
Determination of water content is achieved by using Equation 1.
A - B x 100 .......................... 1
Water Content = A
2. Ash content ASTM D 871-96.
Porcelain bowls were blazed in a furnace at 600 °C for 3 hours, then cooled in a desiccator and weighed
A. A total of 0.2 g of dry sample B was transferred into a porcelain dish of known weight, and then
immediately charred using an electric stove until it ceases to release smoke. Next the sample was cindered
in a furnace at 600 ° C for 3 hours to obtain ashes C.
The ash content was determined using Equation 2. C - A
x 100 .......................... 2 Ash Content =
B
3. α-Cellulose Content SNI 14-0444-1989.
Petri dishes were sintered in an oven heated at a temperature of 105 °C, and then cooled in a desiccator.
Next 0.3 g of dry sample was weighed in a 250 mL beaker. The next procedures were then performed in a
thermostat at 20
o
C. The sample was drenched with 15 mL of 17.5 NaOH and maceration was carried out
with a stirring bar for 1 minute. 10 mL of NaOH solution was added and stirred for 45 seconds. Finally, an extra
10 mL of 17.5 NaOH was added and stirred for 15 seconds. The mixture was allowed to rest for 3 minutes.
The 10 mL of 17.5 NaOH was added to the mixture and stirred for 10 minutes. The addition of 3 x 10 mL
NaOH was repeated at intervals of 2.5 minutes, 5.0 minutes and 7.5 minutes. The sample was left in a
thermostat for 30 minutes in a closed state. Afterthat a 100 ml of distilled water at 20 ° C was added to
the mixture and then the system was allowed to stand
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for 30 minutes. Next, the content of the mixture was poured into a sintered plate already equipped with
a suction lask, and then suctioned with a vacuum pump and the beaker was cleaned with 25 mL of 8.3
NaOH at 20
o
C. Then the precipitate was washed with 5 x 50 mL of distilled water at 20
o
C. Petri disk was transferred to another suction lask
and the precipitate was washed with 400 mL of distilled water. CH
3
COOH 2N was then added, and stirred for 5 minutes. The precipitate was washed with distilled
water until free of acid, and then dried by inserting the petri disk into an oven at 105
o
C. The mixture was then cooled in a desiccator and weighed. α-cellulose
content was determined using Equation 3. α-Cellulose content = precipitate weightsample
weight x 100 ....................................................... 3
4. Acetyl Acetic Acid Content ASTM D 871-96
