João Emidio da S. Neto.; SILVA NETO, J.E.; SILVA NETO, João Emídio da.; http://lattes.cnpq.br/5378979151011506; SILVA NETO, João Emídio da.
Abstract:
In this work, several PP/PBAT blends containing PP-g-MA (0 and 5%w/w) as an
additive as well as three types of lubricants (stearates) (0 and 0.5%w/w) were
prepared by twin-screw extrusion under a single processing condition. The samples
obtained were characterized by torque rheometry, melt flow index (MFI), infrared
spectroscopy (FTIR), mechanical properties (tensile and impact), heat deflection
temperature (HDT), x-ray diffraction (XRD), scanning electron microscopy (SEM),
differential scanning calorimetry (DSC), thermogravimetric analysis (TG), thermal
degradation and biodegradation. The results of torque rheometry suggest
degradation during processing. Melt flow index increased with stearate incorporation.
Mechanical properties and HDT values of PP decreased with the addition of both
PBAT and additives to polypropylene. XRD data showed that the degree of
crystallinity of the blends increased with the addition of the compatibilizer (PP-g-MA)
and of the stearates, while that of DSC indicated that the degree of crystallinity of the
blends decreased with PBAT addition and increased with the incorporation of
additives. SEM images showed that the particle size of the biodegradable polymer
diminished upon addition of the stearates use in the PP/PBAT blends. TG data
showed a reduction in the thermal stability of the systems containing PBAT and
stearates. All samples, particularly those containing stearates, strongly thermally
degraded. The blends investigated biodegrade, provided that the material is pre-
degraded before burial. The rate of degradation is higher in systems with stearates,
which was attributed to the pro-oxidant action of these substances. The incorporation
of the PP into PBAT and stearates is a less harmful alternative to the environment
when compared with neat polypropylene since, under ideal conditions, it is easily
degraded after disposal.