CHAPTER 4
RESULT AND DISCUSSION
4.1 Sample preparation
This section discusses the results of sample preparation. To achieve the first
objective of this study, six samples were prepared by blending palm oil with
Molybdenum Dithiophosphate as friction modifier, Azhari et al, (2015) stated that
Molybdenum containing compounds has proven as a friction modifier additive,
reaction to reduce friction and also good in lubricating. The other additive is Zinc
Diamyl dithiocarbamate which acts as an anti-wear agent. The additives were added
into palm oil with different concentration of MoDTP starting with 0.00 weight percent
to 0.20 weigh percent. This is supported by US patent by Arai et al., (1994) that the
range from 0.03 to 0.18% by weight percent the amount of Molybdenum compound
is preferably to act as anti-friction. A Quintix precision lab balance was used to weigh
the mass of oil and additives to be added into the parent base oil. The concentration of
each component are tabulated as in Table 4.1.
From Table 4.1, it is evident that the total amount of oil used for making first
sample is 200 grams. This sample will later in the text known as Control Sample.
Control sample is prepared using pure palm oil and later will be used to determine the
enhancement that will be made through addition of additives MoDTP and ZDDC. The
addition of MoDTP alone was not effective in improving the frictional characteristics
(Yamamoto and Gondo, 1986). The amount of the ZDDC were constant for each of
samples which is 2 weight percent or 0.4 grams. It is evident that according to Arai et
al., (1997) in a US Patent recommended that the concentration of zinc added into any
lubricant are between 1 wt% to 3 wt%. This is also supported by Liu, et al, (2015) with
2wt% of ZDDC is the most effective concentration. With that, this study is consistent
with the previous studies by remaining the concentration of ZDDC at 2wt%.
The second sample were prepared with 196.0 g of palm oil added into zero
weight percent of MoDTP and will be later tagged in the text knowns as sample 2.
Then, for making sample 3 were used 0.05 weight percent of MoDTP representing 0.1
g of MoDTP are added into 195.9 g of palm oil. For the sample 3 later future known
as sample 3. For the next sample will identified in the text as sample 4 were added
with 0.2 g of MoDTP which is 0.10 weight percent. This is added into 195.8 g of palm
oil. The next sample with 0.3 g representing 0.15 weight percent of MoDTP is added
into palm oil which is as 195.7 g and for this sample next will be known later in the
text as sample 5. After that, with 0.20 weight percent of MoDTP which is consist of
0.5 g of MoDTP are added 195.6 g of palm oil for the last sample and also later in the
text will be named as sample 6
To dissolve all the mixture between base oil and additives, the samples
formulation were heated by immersed the samples into water bath machine to ensure
the dilution of the combination. Table 4.1 display the concentration of parent base oil
and the additives.
Table 4.1: Concentration of weight percentage
Sample
ZDDC (g)
MoDTP (g)
ZDDC
(2wt%)
MoDTP
(wt%)
Palm Oil
(g)
1
0
0
0
0
200.0
2
4.0
0
2.0
0
196.0
3
4.0
0.1
2.0
0.05
195.9
4
4.0
0.2
2.0
0.10
195.8
5
4.0
0.3
2.0
0.15
195.7
6
4.0
0.4
2.0
0.20
195.6
4.2 Sample Testing
This section discusses the result of samples testing. In order to succeed this
section, the samples were prepared with different concentration to observe its behavior
by referring to the standard American Society for Testing and Material (ASTM)
procedure method. In this study, ASTM D6595 test method is used to test the all of
the samples to test the tribological characteristic of each sample.
4.2.1 Metal Content (ASTM D6595)
In this section, upon completion of sample preparation, all the sample
were tested using standard test method which is Rotating Disc Electrode
Atomic Emission Spectrometry (RDE-AES) by referring to the standard
ASTM D6595. It is used to determine the elemental concentration of wear
metals, contaminants, and additives in a used oil sample of palm oil with the
addition of ZDDC and MoDTP. The test is to ensure the dilutions of additives
into parent base oil. In this study, the determination concentration of Zinc,
Molybdenum, and Phosphorus were done. The amounts of concentration were
measured in part per million (ppm).
Control sample contained only pure palm oil and it was revealed that
concentration of Zinc, Phosphorus, and Molybdenum showed less than 1 ppm
respectively. With appearances of constant ZDDC which is 2wt% of the
concentration, it was observed that the concentration of Molybdenum and
Phosphorus presented less than 1 ppm. Meanwhile, the concentration of Zinc
showed 1199 ppm. Based on the result, the concentration of Molybdenum and
phosphorus were increased as the concentration with the presence of MoDTP
which is 0.05 wt%, 0.10 wt%, 0.15 wt% and 0.20 wt%. Based on Table 4.2, it
showed the element of Molybdenum and Phosphorus were increased
proportional based on the increment of the concentration of each sample. An
addition of 0.05 wt% of MoDTP into sample 2 are revealed that Molybdenum
concentration was increased from less than 1 ppm to 63.87 ppm while
phosphorus was 63.87 ppm and 1206 ppm of Zinc. The metal content of
Phosphorus and Molybdenum continued to increase to 34.11 ppm and 131.66
ppm respectively following by the addition of 0.10 wt% concentration of
MoDTP into sample 3. While, the result of a metal content of Zinc is slight
change from 1206 to 1317 ppm. After that, sample 4 with an addition of
concentration at 0.15 wt% MoDTP were indicated with further increment in
Phosphorus and Molybdenum to be 58.19 ppm of phosphorus, and 254.52 ppm
of Molybdenum. On the other hand, the concentration of Zinc was recorded of
decrement from 1317 ppm to 1266 ppm. In sample 5, with addition 0.20 wt%
of MoDTP showed the Phosphorus concentration was recorded to further
increase to 57.47 ppm, with an increment in Molybdenum at 270.39 ppm.
However, Zinc concentration was again reduced to 1178 ppm. The Increment
of Phosphorus and Molybdenum concentration in each sample was due to the
existence of Phosphorus and Molybdenum element inside chemical structure
of MoDTP as depicted in Figure 3.2. It is evident that from the previous studied
