Preparation And Properties Of PP/POP/Wollastonite Composites

Since 1960 s, polypropylene(PP) has been widely known due to its good processability, mechanical properties and low cost. However, its poor impact strength limits the further applications.Addition of thermoplastics,elastomers and rubber can be considered as economical and effective methods to extend its industrial applications.In this paper, polyolefin plastomer(POP) was used as an impact modifier for PP. The effects of components of POP on structure, non-isothermal crystallization and themal-mechanical properties of PP/POP composites were discussed. The PP/POP composites were prepared by a twin screw extruder and injection molding,and analyzed by DSC, SEM and mechanical testing. The results indicated that:As POP content is 10wt%, the notched impact strength of the PP/POP composites is increased to 22.5 k J?m-2 compare with that of 9.6 k J?m-2 of pure PP. But, the tensile strengths of the composites were slightly decreases by adding of POP, the rigidity of PP yet retain well.The impact behaviors of PP/POP and PP/POE were compared. The results showed that the toughening effect of the content of POP on PP is less than POE. As POP content is 10wt%, it was found that the obvious eutectic structure was found to be formed between PP and POP, causing high interfacial adhesion, and then the impact strengths of composite were improved. Compared with PP/POE(90/10), the average impact strength of the PP/POP(90/10) composites increase by 42%,respectively.In addition, PP/POP/wollastonite composites were prepared with wollastonite as reinforcing agent. The effects of wollastonite on the properties of PP/POP blends were studied. The results showed that: the thermal stability of PP/POP/wollastonite composites was improved by adding wollastonite; and wollastonite acted asβ-modification nucleating agent of polypropylene; when wollastonite was 5wt%, the contents of β-PP reached maximum, the PP/POP/ wollastonite composites had the optimal mechanical properties. The better comprehensive properties were obtained for the PP composites with 5wt% wollastonite, 10wt% POP.