the present time the entire world is worried about the impact of condition
contamination and the emissions from vehicle as a result of utilization of
petroleum product is considered as a noteworthy commitment to it. Biodiesel is
turned out to be the best trade for diesel as a result of their excellent
eco-friendly properties. Even
though the biodiesel
is considered as a better fuel than the fossil fuel, the automobile sector is
not ready to accept biodiesel because of less research related to compatibility
of materials with the biodiesel. This lags in the implementation of completely
biodiesel engine in automobiles.
This research work is mainly
focused on the experimental investigation to study the effect of biodiesel on
elastomeric materials used in automobiles and to suggest suitable material in
that field which is having higher compatibility with the biodiesel. The
methodology involvesimmersing the elastomeric materials like NBR, CR, EPDM,
Silicone and Natural Rubber into the biodiesel and evaluating mechanical
behaviors immersed at 250hrs. The experiments shows that the suitability of elastomers for biodiesel is NBR > CR > EPDM >
Silicone > Natural rubber.
Key words: WCO
biodiesel, Elastomers, NBR, CR, EPDM, Silicone, Natural rubber, immersion tests.
The issues of fossil fuel depletion and
environmental degradation are driving the search for the alternative fuels. One
such fuel is biodiesel, another option to diesel fuel created by
transesterification of vegetable oils or animal fats. It offers property near
that of diesel fuel and has no sulfur and no aromatics. In diesel engine, fuel
comes into contact with a wide assortment of materials. Material compatibility
in biodiesel is not quite the same as that in diesel. diesel is a blend of
hydrocarbons, while biodiesel is a blend of unsaturated fat esters. The
similarity of seal, gaskets, hose materials ordinarily utilized as a part of
car fuel frameworks utilizing regular diesel fuel has for quite some time been
Elastomers are essentially complex
blend of polar and non-polar substances including polymers, fillers, oil,
plasticizer, stabilizers, curing operators, cell reinforcements, antizonants
and preparing helps. When it is submerged in a dissolvable, the elastomer
lattice tends to swell. Swelling of EPDM, SR, CR and NBR upon presentation to
fuel can be ascribed to the assimilation of dissolvable and unwinding of
Be that as it may, there is
substantially less data accessible on the similarity of fuel framework
elastomers with biodiesel especially Waste Cooked Oil (WCO) biodiesel. It has
been accounted for that degradation of specific elastomers is one of the
principle issues identified with material compatibility in biodiesel. From the
literature it is clear that the impact of methyl yester and diesel blends on
the elasticity, lengthening, hardness, and swelling of a few basic elastomers
demonstrates different outcomes in view of their exploratory strategies. What
makes the circumstance more complicated is the way that fact that under the
circumstances of exposure, the extent of fuel absorption as well as the
extraction of soluble components of elastomer. Irrespective
of such impacts, a restricted however unequivocal part is generally ascribed to
describe the similarity of various elastomers in biodiesel. The present
examination plans to research the effect of Waste Cooked Oil (WCO) biodiesel on
the degradation value of Nitrile Rubber (NBR), Chloroprene Rubber (CR), EPDM,
Silicone Rubber and Natural Rubber and to propose the perfect material among
Experimental set up:
The compatibility of various elastomeric materials
viz, Nitrile Rubber (NBR), Chloroprene Rubber (CBR), EPDM, Silicone and Natural
Rubber with Waste Cooked Oil (WCO) biodiesel was evaluated by conducting
immersion in B0 (diesel), B20 (20% biodiesel in diesel), B50 (half biodiesel in
diesel), B100 (biodiesel) at room temperature (32 0C) for 250 h.
the end of immersion, degradation of various elastomers was portrayed by
estimating changes in weight, volume, hardness and elongation. Changes in weight
were estimated by adjust with 3 decimal accuracy. The hardness estimation of
the materials was meausred utilizing “Shore A” Hardness analyzer. All
these tests were conducted before and after immersion test.
3. Results and discussions:
a) % Changes in Volume:
Fig. 1 demonstrates the change in
Volume of the elastomers upon exposure with various blends of biodiesel with
diesel fuel. Volume for Nitrile Rubber (NBR), Chloroprene Rubber (CR) and Natural
Rubber increases with expanding the concentration of biodiesel, while for EPDM
and Silicone Rubber displays reduced volume with increments in biodiesel concentration.
Figure 1. Change in Volume of elastomer
for different biodiesel blends for 250hrs.
Elastomers appear to swell in
biodiesel through responses with the polymer backbone and cross-linking
framework, or by responses with the filler system. This results that biodiesel
and its blends cause a grater swelling of CR, NBR and Natural rubber contrasted
and that caused by diesel. Then again, EPDM and Silicone swelled to a more
noteworthy degree in diesel contrasted and that in biodiesel and its blends.
NBR is an complex group of
unsaturated copolymers of acrylonitrile (ACN) and butadiene while Chloroprene
Rubber (CR) alludes to polymers of 2-chloro-1,3-butadiene or copolymers of
2-chloro-1,3-butadiene with at least one polymerizable monomers. The more
noteworthy the acrylonitrile content in NBR, the less the swell in fuels as it
can guarantee expanded cross-linking in the polymer spine 1.
The principle behind the swell of
the elastomer is “like disintegrates like.” There is a general rule
depicting the way that polar substances will probably break down in polar
solvents and nonpolar substances will probably break up in non-polar solvents
2. For polar dissolvable, the positive ends of the molecules will draw in the
negative ends of the solute atoms and accordingly makes an intermolecular power
known as dipo – leedipole association. The level of dipo – leedipole
cooperation in biodiesel for solute is by all accounts higher when contrasted
with that in diesel in light of its extra exceptional synthetic distinction
emerging from the expanded extremity of esters 4. Subsequently, swelling of
same elastomer material is similarly higher in biodiesel than that in diesel
fuel. In the event that the dissolvable polymer collaborations are more
predominant than polymer connections, greatest swelling can be gotten 3.
b) % Changes in
Figure 2. Change in Volume of elastomer
for different biodiesel blends for 250hrs.
It is seen that the compatibility, as far as changes
in weight, for both CR and NBR are higher in biodiesel when contrasted with
that in diesel. Then again, EPDM, SR and Natural Rubber are less perfect with
biodiesel. This can be attributed to the higher extremity of ester segments in
biodiesel which enables the more polar elastomers to disintegrate to dissolve
to a greater extent.
all particles additionally have weak intermolecular forces called London
Dispersion forces by which positive cores of the solute molecule atoms will
pull in the negative electrons of the dissolvable atom molecules 2. This
gives the non-polar dissolvable more noteworthy capacity to solvate the solute
particles. The increase in weight came about as the degree of more liquid
absorption when contrasted with the extraction solvent segments from elastomer.
The expansion in weight can be ascribed to the degree of higher fluid
assimilation when contrasted with the extraction of dissolvable segments from
elastomer. Then again, the causes of lightly reduced weight for CR and NBR can
be attributed to the absorption of lighter component like diesel or biodiesel
and in the meantime, disintegration of dissolvable parts, for example,
plasticizers, stabilizers or added substances from the elastomers 1.
c) % Changes in
Figure 3. Change in Length of elastomer
for different biodiesel blends for 250hrs.
Figure 3.demonstrates the changes
in Elongation of the elastomers upon immense in various biodiesel and their
blends. Elongation for Nitrile elastic (NBR) and Chloroprene Rubber (CR) increased
with concentration of biodiesel and displays lessened length if there should
arise an occurrence of diesel. While for EPDM and Silicone Rubber displays
diminish in elongation with increments in biodiesel concentration while Natural
Rubber shows higher stretching for B20 and B50 blends and bring down extension
for pure biodiesel contrasted and diesel. Notwithstanding, higher change in
length was seen in case of biodiesel.This maybe because of higher absorption of
biodiesel in elastomer.
d) % Changes in
Hardness ( Shore A):
Figure 4. Change in Hardness of
elastomer for different biodiesel blends for 250hrs.
From the figure 4 it
is clear that the shore A hardness value of elastomeric materials will
diminishes when presented to biodiesel. Likewise hardness of CR and NBR in
biodiesel diminishes more contrasted with that for diesel, though the hardness
value for EPDM, Silicone and Natural Rubber shows higher than that of the
diesel. This may demonstrate higher disappearing of crosslinking for
Chloroprene Rubber (CR) after immersion into biodiesel.
elastomers, carbon dark and silica fillers can serve to enhance the hardness.
The expansion of curing specialists and quickening agents cause
cross-connecting between the polymer chains or spine. It is this system of
cross-connects that to a great extent decides these physical properties. Upon
exposure of various elastomers into biodiesel, these cross-connecting agents or
filler appear to respond with components of biodiesel and accordingly fall
apart the physical and mechanical properties.
Not at all like NBR
and CR; EPDM and Silicone does not demonstrate any critical auxiliary change
upon exposure to biodiesel. All representing functional groups remain intact
even after long immersion into biodiesel.
conclusions can be drawn from this investigation as
1. The weight and
volume for NBR, CR and Natural Rubber are expanded with increasing the
concentration of biodiesel while for EPDM and Silicone Rubber it diminishes
with biodiesel concentration.
2. After immersion
into biodiesel, elongation and hardness were significantly reduced for both
EPDM and silicone while extremely negligible changes were found for Natural
Rubber, though CR and NBR demonstrates unfavorable with these materials.
containing ester has more carboxylic gatherings when contrasted with those in
petrodiesel. Elastomers are appeared to be debased more by those carboxylic
polar groups of biodiesel.
obtained results from this work can assure consumer that the compatibility of
elastomers for biodiesel is NBR > CR > EPDM > Silicone > Natural