NASCIMENTO, U. A.; NASCIMENTO, Uédson Alexandre do.
Resumo:
This study investigated the effect of plasticizer polybutene (PIB) of
molecular weights ranging from 480 to 1.600g/mol in polypropylene
homopolymer (film grade). Compositions of 0, 3, 5 and 7% of PIB10 (480g/moJ),
PIB30 (1.250g/mol) and PIB120 (1.600g/mol) were prepared in internal mixer,
which were also obtained the curves of torque versus time for the mixtures.
Were made samples for the laboratory tests of tensile strength, Shore D
hardness, differential scanning calorimetry (DSC), scanning electron
microscopy (SEM), infrared with Fourier transform (FTIR), X-ray diffraction
(XRD) and rate of flow (Ml). The results of mechanical tests showed the effect
of plasticizer*s PIB, compared with the pure PP, with a drop in tensile strength,
elastic modulus and Shore D hardness. The DSC thermograms showed the
displacement of melting peak (Tm) to lower temperatures and crystallization
(Tc) to higher temperatures, giving a further indication of the effect of
plasticizerJs PIB on the PP. The analysis of XRD showed a drop in the degree of
crystallinity of PP/PIB blends. The micrographs obtained by SEM did not reveal
the occurrence of the phase separation, confirming the miscibility of mixtures
used. The Ml analysis confirm the effect of internal lubricant's of PIB, by
increasing the rate of flow of mixtures and promoting overlubrification effect in
higher concentrations. By FTIR were not identified thermoxidative degradation
from the process of mixing.
