Properties Of PB-1/LLDPE Blends Compatibilized By PB-LLDPE

Iso-polybutene-1 (PB-1) has good properties such as thermal creep esistance, environmental stress crack resistance, grinding resistance and superior processibility, therefore, it is honored as the "golden plastic". In this paper, PB-1 was blended with linear low density polyethylene (LLDPE) to improve the performance of PB-1 and reduce it’s costs. The PB-1/LLDPE blends were made, and its overall performance was investigated. Considering the incompatibility of PB-1 and LLDPE, PB-1/PB-LLDPE/LLDPE blends were prepared by melting blending PB-1 and LLDPE with the ratio of 80/20 through extruder, using PB-LLDPE as compatibilizer which synthesised by melting grafting and crosslinking polymerization of PB and LLDPE. The morphology, the crystallization, mechanical properties and the melt rheological behavior as well as the thermal deformation property of the blends were studied via scanning electron microscope (SEM), polarized optical microscopy (POM), differential scanning calorimetry (DSC), Wide angel X-Ray Diffract meter (WXRD), mechanical testing machines, vicat softening point tester and capillary rheometer, respectively.The results showed that:PB-1 and LLDPE phases in the blends had some interaction. After adding the LLDPE, the PB-1 formed small crystal and the crystal of two components became perfect, the toughness of the blends was increased obviously, the tensile strength of the blends was close to the values obtained by the linear addition method.When the PB-1/LLDPE blends were made after seven days, the two components retained their diffraction peaks respectively without new crystal. PB-1 only existed in crystal form II when it made after five hours, but 24 hours later it had crystal form Ⅱ and Ⅰ, 120 hours later the crystal transition was substantially completed. The vicat softening point of PB-1/LLDPE blends could be reduced with the addition of LLDPE.When preparation temperature of the compatibilizer PB-LLDPE was 150 ℃, mixing time was 4.5 min, BPO content was 1.5wt%, the ratio of PB-1 and LLDPE in the compatibilizer was 70:30, PB-LLDPE exhibited obvious compatibilization efficiency to PB-1/LLDPE blends The adding of PB-LLDPE in PB-1/LLDPE blends enhanced the compatibility between the two components, reduced the particle size of LLDPE and the spherulites size of the two components, which improved the mechanical properties of the blends...