Multiblock terephthalate copolymer as impact modifier for poly(propylene)/poly(butylene terephthalate) blends

The melt polycondensation method was investigated for the synthesis of a multiblock copolymer. The copolymer consisted of hard segments of poly(butylene terephthalate) (PBT) and soft segments of dimerised fatty acid. This multiblock copolymer was characterised by 1H and 13C NMR and FTIR spectroscopies and differential scanning calorimetry. The 1H NMR method was used for estimating quantitatively the amount of the hard/soft segments. The polymer morphology was characterised using light microscopy and transmission electron microscopy. The investigated polymer was used in a small amount as an additive to poly(propylene)/PBT blends in order to evaluate its influence on the morphology and impact properties of these blends.