Gel acrylonitrile–butadiene elastomer toughened polyoxymethylene blends

The polymer blends of polyoxymethylene (POM) and gel acrylonitrile–butadiene elastomer (GNBE) with phenol formaldehyde resin (PFR) as the compatibiliser were prepared, and the structure and properties were studied. The results show that GNBE is an excellent toughening agent for POM. The blend POM/GNBE (80/20) with 6 phr PFR attains a notched Charpy impact strength of 21·6 kJ m⁻², an elongation at break of 133% and a tensile strength of 33·8 MPa. PFR is incorporated into GNBE and the hydroxyl groups in PFR form intermolecular hydrogen bonds with POM. Dynamic mechanical analysis studies show that POM and GNBE are partially miscible and the miscibility of the blends is improved by PFR. The results from TEM show that the size of the dispersed phase of the ternary blends decreased with increasing PFR content in the blends. A rubber band of GNBE dispersed phase and a complex wrapped structure in POM were observed in the POM/GNBE and POM/GNBE/PFR blends.