Mechanical properties and permeability of polypropylene and poly(ethylene terephthalate) mixtures

Preparing copolyester–titanium dioxide nanocomposites with low melting point via in situ hydrolysis, catalysis and esterification process

Copolyester (CP)-titanium dioxide (TiO2) (CPT) nanocomposites with low melting point were synthesized by esterification of terephthalic acid, isophthalic acid, ethylene glycol and 1,4-butanediol monomers in the presence of tetrabutyl orthotitanate (TBOT). TBOT hydrolysis caused the TiO2 nanoparticles to act as catalysts for polymerization. Transmission electron micrographs showed that the TiO2 nanoparticles with the content ranging from 0.2 wt% to 0.4 wt% were well dispersed in the copolyester matrix. The thermal properties of the nanocomposites were assessed by differential scanning calorimetry. The melting point of CPT nanocomposite with 1.2 wt% TiO2 was 201.9°C, significantly lower than that of pure polyethylene terephthalate (above 260°C). Therefore, the obtained CPT nanocomposites with low melting point are potentially better for industrial applications than the commercial product.

Enhancing the dyeability of polypropylene fibers by melt blending with polyethylene terephthalate

Attempts were made to modify polypropylene fibers by melt blending with polyethylene terephthalate in order to enhance the dyeability of the resultant fiber. Five blends of polypropylene/polyethylene terephthalate/compatibilizer were prepared and subsequently spun into fibers. Three disperse dyes were used to dye such modified fibers at boiling and 130 °C. The dyeing performance of the blend fibers, as well as the morphological, chemical, thermal, and mechanical properties, of the corresponding blends was characterized by means of spectrophotometry, polarized optical microscopy, scanning electron microscopy (SEM), FT-IR spectroscopy, differential scanning calorimetry (DSC), and tensile testing.