Abstract
Biodiesel
is subject to degradation processes like oil and grease. The oxidative
degradation products of vegetable oil esters in biodiesel particularly lead to
enhanced sedimentation in blended fuels.
The
polarity of biodiesel increases its solvency and facilitates permeation and
extraction. Solvation, swelling and/or extraction lead to changes in the
physical properties and chemical changes of polymeric materials. It also
accelerates the degradation (hydrolysis and oxidation) of these materials with
the loss of additives and stabilizers.
The
objective of this research was to determine the resistance of frequently used
polymeric materials such as ACM, EPDM, FKM, FVMQ, CR, CSM, IIR, HNBR, NBR, PA,
PE; POM, PUR, PVC and VMQ in biodiesel and heating oil with 10 %/20 % biodiesel
(B10/B20) at 40°C and 70°C. Mass, tensile strength and breaking elongation of
the test specimens were determined before and after the exposure for 84 days in
the biodiesel heating oil blends. The visual examination of some elastomer test
specimens clearly showed the great volume increase until break or partial
dissolution. Shore hardness A and D were determined before and after exposure
of the test specimens in the biofuels for 42 days.
The
elastomers CR, CSM, EPDM, IIR, NBR and VMQ were generally not resistant to
biodiesel and B10 at 40°C and 70°C. FKM, ACM, HNBR, PA, PE, POM, PVC and PUR
showed high compatibility in B10/B20 at 40°C. A lower compatibility was
determined for ACM in biodiesel. ACM and HNBR were not resistant in B20 at
70°C.