INVESTIGADORES
FAILLA Marcelo Daniel
congresos y reuniones científicas
Título:
Study of Thermal Behaviour of Propylene Copolymer/o-MMT Nanocomposites
Autor/es:
VERÓNICA RIECHERT; LIDIA M. QUINZANI; MARCELO D. FAILLA
Reunión:
Conferencia; 6th International Conference on Science and Technology of Composite Materials COMAT.; 2015
Resumen:
Polymer nanocomposites containing nanoclaysas filler are a new generation of materials. The incor­poration into the polymer bulk of small amounts of silicatesplatelets, with high aspect ratio, enhances mechanical, physical and barrierproperties, retaining the transparency and the relatively low density of thepolymer.In this work a commercial random propylene-ethylene-buteneter copolymer with 3wt% of ethylene and 8wt% of 1-butene (PEBC) was melt mixedwith different amounts of a commercial organophilic montmorillonite (o-MMT)using as compatibilizer the PEBC functionalized with maleic anhydride (PEBCg). ThePEBC was modified by grafting the anhydride employing reactive melt processing.Two PEBCg´s were synthesized: PEBCg1 with 0.44wt% of maleic anhydride andPEBCg2 with 0.57wt%.A set of composites of PEBC/PEBCg1/o-MMTwere prepared using three clay concentrations (2, 5 and 8wt%) and keeping thePEBCg1/clay ratio in 3:1. Another set of PNCs were generated using 5wt% ofo-MMT and PEBCg2/o-MMT ratios of 1:1, 2:1 and 3:1. Blends of PEBC/PEBCg2 withproportions of components equivalent to those of the composites were alsoelaborated.The results of X-ray diffraction and scanningelectronic microscopy show that intercalated/exfoliated composites wereobtained, with homogeneous distribution of clay platelets and tactoids in thepolymeric matrix. The thermal behaviour of the materials wasstudied by calorimetry and thermogravimetry. The crystallization temperature ofthe PEBC/PEBCg2 blends is higher than that of the PEBC, while the addition of claydecreases to some extent this temperature. This phenomenon indicates a slightnucleating effect of the grafted polymer, which is diminished somewhat when theclay is incorporated. This result was confirmed by comparing the value of the activationenergy of crystallization, which was estimated using an iso-conversionalmethod. The thermogravimetric results show that the addition of the clayincreases the degradation temperature of the PEBC by 40°C but accelerate thedecomposition process.