The Application Of Nano-CaCO₃ In ABS Engineering Plastics

ABS resin is one kind of thermoplastic plastics with comprehensive mechanical properties. The application range of the ABS resin is limited because of its poor weather resistance, low flame resistance, transparency and its high cost. Nano-CaCO3 particles have been employed to improve properties and lower cost of polymer products effectively as functional filler. Incorporation of nano-CaCO3 particles is a industrial promising approach. In order to lower the cost, the effect of CaCO3 on the notched impact strength, flame-retardant and flow properties of ABS composites were studied according to the general grade requirement of GB 10009-88.(1) ABS/CaCO3 composites filled with high content of nano-CaCO3 was prepared using SBS and EVA as toughened modifier by melt extrusion method. The results indicated that the notched impact strength of ABS/CaCO3 composites fell to 80 J/m when the content of nano-CaCO3 was about 19.2 w%, and the tensile strength and flexural strength was decreased slightly. The toughening effect of SBS on ABS/CaCO3 composites was better than that of EVA. When the content of toughened modifier was low, SBS was are superior to EVA counterparts in improving processing flow properties.(2) Then, the effect of HIPS on mechanical properties of ABS/CaCO3 composites was also studied in order to lower the cost. Furthermore, the mechanical properties of nano-CaCO3/HIPS/ABS composites were studied using three processing technologies including direct blending extrusion, masterbatch and twice extruding method. It was found that mechanical properties of nano-CaCO3/HIPS/ABS composites prepared by masterbatch method were better than those of direct blending extrusion and twice extruding method. Besides, nano-CaCO3 were dispersed in ABS matrix relative uniformly by masterbatch method.(3) ABS/PVC composites can be prepared by blending and modification. The effect of toughened modifier content and kinds (EVA, CPE and SBS) on notched impact strength, tensile strength and limiting oxygen index (LOI) of PVC/ABS composites were studied. Furthermore, the mechanical properties, melt mass-flow rate (MFR) and LOI of nano-CaCO3/CPE/PVC/ABS composites were investigated. The results indicated that the LOI reached to 28.0 when the ratio of PVC/ABS was 70/30, while the notched impact strength of PVC/ABS reduced to 70 J/m which reduced by 60% compared to the pure ABS. Besides, mechanical properties and flame-resistant effect of PVC/ABS composites modified by CPE were superior to those of EVA and SBS. The notched impact strength of nano-CaCO3/CPE/PVC/ABS composites reached a maximum when the content of nano-CaCO3 was about 5.0 w%, and the tensile strength and flexural strength was decreased slightly with the increase of nano-CaCO3 content. The LOI of nano-CaCO3/CPE/PVC/ABS was decreased with the increase of nano-CaCO3, and yet, MFR of nano-CaCO3/CPE/PVC/ABS composites was improved when nano-CaCO3 content was within a certain range.(4) ABS/PMMA composites filled with different content of PMMA was prepared by melt extrusion method. ABS/PMMA composites was modified using SBS, EVA and nano-CaCO3 as toughened modifier. The results indicated that the gloss, hardness, tensile strength and of ABS/PMMA composites were improved obviously, but the notched impact strength and MFR of ABS/PMMA composites was decreased with the increase of PMMA. With the increase of nano-CaCO3 content in ABS/PMMA/nano-CaCO3 composites, the notched impact strength increased before decreasing, and the notched impact strength reached the maximum as 140 J/m with 5.6 w% nano-CaCO3 content.. And the toughening effect of SBS on ABS/PMMA composites was better than that of EVA.