Efeito de polibutenos nas propriedades físicas e mecânicas do polipropileno.

Abstract

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.