Isothermal Crystallization and Crystallization Morphology of Non-cross-linking Linear Low-density Polyethylene-grafted-acrylic acid

摘要

Non-cross-linking linear low-density polyethylene-grafted-acrylic acid (LLDPE-g-AA) was prepared by melting reactive extrusion in our laboratory. The thermal behavior of LLDPE-g-AA was investiated by using differential scanning calorimetry (DSC). Compared with neat linear low-density polethylene (LLDPE), melting temperature (Tm) of LLDPE-g-AA increased a little, the crystallization temperature (Tc) increased about 4 deg C, and the melting enthalpy (#DELTA#Hm) decreased with increase of acrylic acid content. Isothermal crystallization kinetics of LLDPE and LLDPE-g-AA samples was carried out using DSC. The overall crystallization rate of LLDPE was smaller than that of grafted samples. It showed that the grafted acrylic acid monomer onto LLDPE acted as a nucleating agent. Morphologies of LLDPE-g-AA and LLDPE were examined using SEM. Spherocrystal diameters of LLDPE-g-AA sampels were lower than that of LLDPE.