Naslov
Effect of EPDM on mechanical properties, crystallisation behaviour and viscoelastic properties of PP/HDPE blends

Autori
Vranješ, Nina ; Rek, Vesna

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Polychar 15 : 15th World Forum on Advanced Materials : Abstracts / Lucas, Elizabete F. - Rio de Janeiro : In-Folio-Producao Editorial, 2007

Skup
Polychar 15 : 15th World Forum on Advanced Materials

Mjesto i datum
Armação de Búzios, Brazil, 16.04.2007. - 20.04.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Mechanical properties; crystallisation behaviour; viscoelastic properties; PP/HDPE blends; EPDM

Sažetak
Polypropylene (PP) and polyethylene (PE) are widely used plastics in the world. The blending of them resulted by variation of properties compared to neat homopolymers. Unfortunately, PP and PE are highly immiscible resulting in a blend with poor adhesion among its phases, coarse morphology and consequently poor mechanical properties. The compatibility between phases of a blend can be improved by addition of compatibilizers, which results in a finer and more stable morphology, better adhesion between the phases of the blends and consequently better properties of the final product.1 Effect of ethylene-propylene-diene (EPDM) terpolymer as compatibilizer on mechanical properties, crystallisation behaviour and dynamical mechanical properties of isotactic polypropylene (iPP) and high density polyethylene (HDPE) blends were investigated. The samples of neat homopolymers and their blends were prepared by extrusion in twin screw extruder and injection molded. Mechanical properties of investigated systems were determined by Instron 1185. Tensile strength at break, elongation at break and yield stress were measured according to ISO 527 standards. Izod impact strength was measured according to ISO 180 standard. Crystallisation behaviour was determined by Differential Scanning Calorimeter, DSC, DSC 2910, TA Instruments, according to ASTM D-3418-82 standard. Dynamic Mechanical Analyzer 987, DMA, Ta Instruments were used to determined the storage modulus, E', loss modulus, E'', and loss modulus, tan δ . Tensile strength at break decreased by the addition of HDPE to the iPP phase. The EPDM content also decreased the tensile strength at break and it was much more expressed in 80/20 iPP/HDPE composition. Elongation at break decreased with the addition of HDPE to the PP phase. The improvement of elongation at break was achieved by the addition of EPDM to iPP/HDPE blends, especially in iPP/HDPE 80/20 blend. Yield stress decreased by the addition of HDPE as well as by the EPDM content. The binary iPP/HDPE blends had low impact strength value, due to their incompatibility, while the addition of EPDM increased it. The effect on impact strength is much more expressed in iPP/HDPE 80/20 blend. Melting temperature of iPP phase in iPP/HDPE blends did not significantly change by the HDPE and EPDM content. Melting temperature of HDPE phase in iPP/HDPE blends slightly decreased by the addition of iPP and EPDM content. Degree of crystallinity of iPP phase in iPP/HDPE blends decreased by the addition of HDPE phase, while for HDPE phase increased with lower amount of iPP. The addition of EPDM increased the crystallinity of iPP, while for HDPE showed increasing in iPP/HDPE 40/60 blend and for iPP/HDPE 80/20 blend decreasing. Dynamical mechanical analysis showed glass transitions of iPP and HDPE phase, as well as the relaxation transitions of their crystalline phase. By addition of EPDM glass transition of HDPE and iPP phase in iPP/HDPE blends decreased. Storage modulus was decreased with higher HDPE content.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

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