| 초록 |
Recently, the regulations on international fuel efficiency and greenhouse gas emissions have been strengthened. So, the automobile industry has been increasingly interested in lightweight materials, hollow glass microspheres (HGMs). High specific mechanical properties would be achieved if HGMs with less than the density of 0.5 g/cm2 are put together with glass fiber (GF) to meet industrial needs. However, the breakage of the HGMs occurred due to both extrusion and injection molding process and increase of the viscosity due to the high content of the inorganic fillers. Through aliphatic hyperbranched polyesters based on 2,2-bis(methylol)propionic acid, melt flow index doubled compared to the PA6/HGMs/GF composite, reduced the breakage of the HGMs. The breakage of the HGMs was observed by SEM and two methods of density measurement, resulting in surface clearness of the composite and an unexpected increment in tensile strength from 59 to 73 MPa and flexural modulus from 4032 to 4424 MPa. |
