Surface modified CaCO3 by palmitic acid as nucleating agents for polypropylene film: mechanical, thermal and physical properties

摘要

Composite films of polypropylene (PP) and modified calcium carbonate (CaCO3) were prepared in a twin screw extruder with particle content varying from 0.5, 1.0, and 1.5 phr. The CaCO3 surface was modified by palmitic acid (PA) at 1, 3, and 5 %wt. The modified CaCO3 surface was characterized by FTIR and XRD to indicate that the modifier is combined on the CaCO3 surface. The results showed that optimum of PA attached to that CaCO3 surface was 5 %wt. The influence of modified CaCO3 with and without PA of PP film on the mechanical (tensile strength, Young's modulus and elongation at break), barrier (OP), thermal (DMTA, DSC), physical (XRD, SEM and OM) properties were studied. The results observed that incorporation of modified CaCO3 0.5 phr into PP film showed more dispersion than PP with CaCO3. Furthermore, the addition modified CaCO3 increased tensile strength, Young's modulus, oxygen permeability and melting point from 22.10 MPa, 984.21 MPa, 3.22x10~(-17) m.m~3/s.m~2.Pa, and 156.16 °C (neat PP) to 28.38 MPa, 1222.88 MPa, 3.43x10~(-17) m.m~3/s.m~2.Pa, and 160.37 °C (PP/0.5 modified CaCO3), respectively. The finding on PP/modified CaCO3 composite films has potential for microwaveable packaging.