Research On PC/PP Blends And Their Calcium Carbonate Composite Materials

Polycarbonate exhibits good physical and mechanical properties. It's mechanically stiff and tough, with good thermal stability and optical clarity. In addition, it has good heat resistance and dimensional stability. However, the biggest drawback of polycarbonate is its strong internal stress and notch sensitivity, that can easily form cracks under stress. What's more, its compatibility with other resins is not good. Polypropylene is a kind of widely used polymer,it has smaller density and lower cost, it shows good mechanical properties with a long elongation at break and good processing ability. Blending polypropylene with polycarbonate can not only improve the notched impact strength of polycarbonate, but also improve its processing ability and reduce the cost. PC/PP blends are studied in this work, the PP – GMA is prepared as a compatibilizer to improve the compatibility of them. Besides, the modified nano calcium carbonate is also used as an inorganic filler to improve their performance and further reduce the cost of materials at the same time.The main results and conclusion of this paper are as follows:(1) Lure the blending ratio of PC and PP to prepare different PC/PP blend, then use the universal mechanical testing machine and cantilever beam impact testing machine to evaluate the mechanical performances including tensile strength, elongation at break, bending strength and notched impact strength of the material, the melt index instrument was used to test the liquidity of the material while scanning electron microscopy was used to characterize the microstructure of the material. Results show that with the increase of the PP content in PC matrix, the elongation at break and notched impact strength of the material increases, the tensile strength and bending strength gradually reduce and the melt flow index increases with the increase of PP content. The poor compatibility of them was believed to be the reason to limit mechanical properties has a large effect on the performance of the material.(2) Adopt PP- GMA as a compatibilizer in the PC/PP blend to prepare samples with different ratio. Use Fourier infrared spectrum to characterize the graft copolymerization of compatilizer, the universal mechanical testing machine and cantilever beam impact testing machine was used to evaluate the mechanical performances including tensile strength, elongation at break, bending strength and notched impact strength of the material while the melt index instrument to test the liquidity of the material while scanning electron microscopy was used to characterize the microstructure of the material. We found that after adding the compatibilizer, the variation trend of mechanical properties for the material has almost remained unchanged, but its performance is superior to that without the compatilizer. A homogeneous microstructure of the material is presented and the liquidity is further improved.(3) Add nanometer calcium carbonate in the PC/PP blend, then use the universal mechanical testing machine and cantilever beam impact testing machine to evaluate the mechanical performances including tensile strength, elongation at break, bending strength and notched impact strength of the material, the melt index instrument was used test the liquidity of the material while scanning electron microscopy was used to characterize the microstructure of the material. Results show that the tensile strength of the material increases with the increase content of the nano calcium carbonate, the elongation at break, bending strength and notch impact strength of the material presents a trend of declining after rising with the increase of the content of calcium carbonate. By means of scanning electron microscope, microstructure of the material shows a homogeneous state since inorganic particles and polymer matrix combined closely. When the amount of nano calcium carbonate is large, the liquidity of PC/PP composites decreases.