Effect of Epoxy-Functionalised Core-Shell Particles on Properties of Poly(Butylenes Terephthalate) (PBT)

Abstract

Glycidyl methacrylate (GMA) functional core-shell impact modifiers of butyl acrylate as a core and methyl methacrylate as a shell (gACR) have been prepared by a multi-step seeded emulsion polymerisation. FTIR spectroscopy results show that GMA had been grafted onto ACR and the GMA content in gACR was measured by titration of the epoxy groups. DMA was used to characterise the mechanical properties of the PBT/gACR blends. DSC results showed that the melting point of PBT shifted to lower temperature with an increase in GMA content. Scanning electron microscopy (SEM) images showed that the dispersion of gACR in PBT was uniform. The optimum recipes for gACR toughened PBT had a GMA content of 3% (wt) in gACR resins. The gACR particle size was about 350 nm and the gACR content was 20% (wt) in PBT resins. The notched impact strength of PBT/gACR blends exceeded 440 J/m. It was confirmed that functional core-shell impact modifiers are efficient in toughening PBT.