Study on Morphology, Thermal and Rheological Properties of Polypropylene/Poly(trimethylene terephthalate) Polyblend Fibers

In the present work, a systematic study of the variables affecting the production of polypropylene (PP)/poly(trimethylene terephthalate) (PTT) blend fibers such as the PTT and PP-g-MA compatibleizer ratios and take-up speed in the melt-spinning process was done. Modeling of the melt-spinning process was carried out by using a statistical approach based on response surface methodology (RSM) to achieve a mathematical model. The formation of the fibrillar structures through different steps of fiber formation was confirmed by scanning electron microscopy (SEM). The lowest mean diameter of nano-fibrils was achieved to be 63 nm, for the hot-drawn fibers consisting of 10 wt.% of PTT. The synergetic effect of the presence of PTT dispersed phase on the mechanical properties of PP fibers as a matrix was verified by observing a positive deviation from the blends linear law for the samples with 10 wt.% of PTT. The rheological evaluations suggested the formation of a fibril structure in the blends. The X-ray diffraction spectroscopy and DSC results showed that the presence of PTT significantly influenced the crystallinity of PP. Moreover, results indicated that the average crystal size of the PP matrix phase was affected by the presence of the PTT dispersed phase, which also confirmed its nucleating effect in the blend.