2 research outputs found
Toughening of Immiscible rPS/SAN Blends by SEBS Elastomers: Properties and Morphology
In this research, an attempt was made to improve compatibility in a polymer
blend composed of incompatible constituents, namely, recycled polystyrene
(rPS) and polystyrene-co-acrylonitrile (SAN), through the addition
of a compatibilizer. The compatibilizing agent, styrene-ethylenebutadienestyrene
block copolymer (SEBS), was added to the polymer blend in ratios
of 5 and 10 wt%. For this purpose, blends of rPS and SAN at different ratios,
without and with varying concentrations of compatibilizer, were prepared
by melt blending using a co-rotating twin-screwextruder. Mechanical
properties including tensile and impact strength, rheological properties
(RPA), thermal behaviour (DSC) and morphological characteristics (SEM)
were evaluated. According to the results obtained by complex viscosity, the
blends behave as a pseudoplastic fluid. The results showed that the addition
of SEBS increased the Izod impact strength and the elongation at break and
decreased the tensile strength and tensile modulus. rPS/SAN blend modified
with SEBS had better mechanical properties than the rPS/SAN alloy.
SEM photographs revealed that the SEBS was not only distributed in the
SAN phase but also distributed in rPS phase in rPS/SAN/SEBS blend. Furthermore,
DSC analysis for blends of rPS/SAN gave a good indication of the
improvement on miscibility for most compositions. SEM micrographs of
tensile fracture surfaces indicated that the formation of the co-continuous
phase and the improvement of interface adhesion are the most important
reasons for the excellent tensile properties of the rPS/SAN/SEBS blends.
Within the range of analysed compositions, the morphologies investigated
by SEM are typical of immiscible blends.K.B. would like to thank Dr Maria del Pilar Posadas Bernal, Dr Patricia Sampe-
droTejedor and Grupo de Elastomeros for their help in hosting him as a doctoral
student to carry out the experimental part of his PhD thesis at the Elastomeros
laboratory, Instituto de Ciencia y Tecnologia de Polimeros (ICTP-CSIC) Madrid,
Spain. This research was funded by Spanish Ministry of Science and Innovation
(MINECO) through the research projects RTI2018-096636-J-100 and PID2020-
119047RB-100.Peer reviewe