Sifat-sifat adunan Poli(Vinil Klorida) kitar semula / getah Akrilonitril Butadiena dan adunan Poli(Vinil Klorida) baru / Poli(Vinil Klorida) kitar semula / Getah Akrilonitril Butadiena
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Date
2005
Authors
Supri
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Recycled poly(vinyl chloride)/acrylonitrile butadiene rubber ( PVCr/NBR) blends
and virgin poly(vinyl chloride)/recycled poly(vinyl chloride)/acrylonitrile butadiene rubber
(PVCv/PVCr/NBR) thermoplastic elastomers blends were studied. The blends were
melt mixed using a Haake Rheomix Polydrive R600/610. The processing conditions of
temperature at 1500C, rotation speed at 50 rpm and mixing time at 9 minutes and 11
minutes for dynamic vulcanization system were investigated. The results indicated that
at a similar blend composition, dynamically vulcanized PVCr/NBR blends have higher
tensile strength, stress at 100% elongation (M100), stabilization torque, mechanical
energy, swelling resistance and thermal stability but lower ageing resistance and glass
transition temperature, Tg than virgin poly(vinyl chloride)/acrylonitrile butadiene rubber
(PVCv/NBR) and PVCr/NBR blends. The effect of partial replacement of PVCv with
PVCr in PVCv/PVCr/NBR blends improved the stabilization torque, mechanical
energy, and ageing resistance with increasing PVCr content of the blends. Partial
replacement of PVCv with PVCr also increased tensile strength, stress at 100%
elongation, oil and toluene resistance and glass transition temperature compared to
PVCv/PVCr/NBR blends (0/60/40). Properties of dynamically vulcanized virgin
poly(vinyl chloride)/recycled poly (vinyl chloride)/ acrylonitrile butadiene rubber
(PVCv/PVCr/NBR) with different sulphur concentration were investigated. Results
show that tensile strength, stress at 100% elongation, stabilization torque, mechanical energy, swelling resistance in toluene and oil, and thermal stability, all increased with
increasing sulphur concentration, but elongation at break exhibited the opposite trend.
Dynamically vulcanized PVCv/PVCr/NBR also showed poor ageing resistance at 700C
for 168 hours. Scanning electron microscopy (SEM) examination of the tensile fracture
surfaces of PVCv/PVCr/NBR blends indicated that a higher energy is needed to cause
catastrophic failure as the sulphur concentration increased. The presence of various
compatibilizers such as maleic anhydride (MAH), acrylic acid (AAc) and maleic acid
(MAc) in PVCr/NBR blends have increased stabilization torque, mechanical energy,
tensile strength, stress at 100% elongation and glass transition temperature but
lowered the elongation at break (Eb), ageing resistance and thermal stability compared
to PVCr/NBR blends without compatibilizers. The scanning electron microscopy (SEM)
study of tensile fracture surfaces of the blends indicated that the presence of various
compatibilizers increased interfacial interaction between PVCr and NBR phases is
better interaction with many tear lines. However, at a similar blend composition, the
effects of various compatibilizer and dynamic vulcanization of PVCr/NBR blends
showed mechanical properties (tensile strength, stress at 100% elongation and
elongation at break), swelling resistance and thermal stability that were superior to
PVCr/NBR blends only subjected to the addition of compatibilizers. SEM examination
of the tensile fracture surfaces showed that crosslinked blends could be strained
higher than blends without crosslink. The addition of maleic anhydride (MAH) to
PVCr/NBR blends improved the tensile strength, swelling resistance and thermal
stability better than the addition of acrylic acid (AAc) and maleic acid (MAc). However,
at a similar blend ratio, the presence of maleic acid (MAc) increased the stress at
100% elongation and elongation at break of blends. Results from FTIR studies
revealed that interaction adhesion in PVCr/NBR blends with the addition of
compatibilizer. This is a direct evidence of the nature of specific intermolecular
interaction between PVCr with NBR phases. Scanning electron microscopy (SEM)
examination of the tensile fracture surfaces of blends indicates that interaction adhesion between PVCr-MAH-NBR improved compatibility with many tear lines and
more homogeneous blends than PVCr/NBR + MAc and PVCr/NBR + AAc blends.
Rheological studies involving the Haake Rheometer were used to evaluate the effect
of compounding parameter on the rheological properties of the blends. Rheological
properties of blends where PVCv was partially replaced by PVCr in the
PVCv/PVCr/NBR blends showed that the apparent viscosity, torque, activation energy
and shear stress increased with increasing the PVCr content of the blends. In
dynamically vulcanized PVCv/PVCr/NBR blends, the shear stress, torque and apparent
viscosity are found to increase with increasing sulphur concentration. Effect of dynamic
vulcanization of blends exhibited pseudoplastic and strong non-Newtonian flow. The
presence of maleic anhydride and maleic acid in PVCr/NBR (50/50) blends increase
apparent viscosity and decrease activation energy, Ea more than PVCr/NBR + AAc
blends. At a similar shear rate, dynamically vulcanized PVCr/NBR + MAH and
PVCr/NBR + MAc blends showed higher the Ea than dynamically vulcanized
PVCr/NBR + AAc. For rheological properties were found that increase in cross-link
density impeded flow although this effects is absent at higher shear rate and shear
stress. As typical polymeric liquids, the PVCr/NBR melts are pseudoplastic in nature
(n<1) and they also show non-Newtonian behaviour.
Description
Ph.D
Keywords
Materials and Mineral Resources Engineering , Rubber blends