Figure 15.
Synthesized PUR samples
THE 3
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INTERNATIONAL SCIENTIFIC CONFERENCES OF STUDENTS AND YOUNG RESEARCHERS
dedicated to the 99
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395
In this present study, to obtain PET-based polyols, the glycolysis
process is selected as the most desirable and commercially applied, and the
green method (green reagent, mild condition) and PET-based polyols are
derived from various ratios of PET to glycol as 1/4, 1/5.5, 1/8 and 1/12, using
2 wt% zinc acetate as a catalyst in a closed system at
180 ± 5°𝐶
to
investigate the glycol effect on properties. Moreover, it was achieved to solve
the problems associated with PET-based polyols such as solidification and
high viscosity (which make obstacles to the processing of PUP foams) by the
direct physical mixing of castor oil and glycerol with PET-based polyol. As a
result, obtained polyols were dissolved in the bio-oil mixture, and the
viscosity of the final polyol mixture was significantly reduced. So by this
innovative approach, castor oil was used as polyol without applying any
pretreatment for inserting OH group into the structure because the insertion
of OH group on each of the castor oil ricinoleic chains was compensated by
using 10% glycerol and optimized content (Table 1) of polyol mixture (which
is giving desired PUR properties low fragility, higher dimensional stability and
rigidity) was obtained in Sample 9 shown in Figure 1.
Table 4.
Formulation for PUR synthesis
PUR synthesis was conducted by the free rising method in a thick paper
cup by adding the required TDI amount into the polyol mixture and mixing it
for 40-70 seconds. The properties of the appropriate PUR at determined
formulation were measured and shown that mechanical properties of foams
increased with increasing PET content in polyol so that compression strength
of PUR foam was enhanced by 3.5 times, and tensile strength and elongation
of pressed PUR samples increased by 20% and 23%, respectively, shown in
Figure 2 and 3.
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