The Preparation And Research Of New Structure Of Polypropylene Nucleating Agent

The wide uses of polypropylene (PP) in different fields afford a new topic in the modification research and technological exploration to polypropylene. According to the characteristics of polypropylene, adding a nucleating agent is one of the effective means of modification to polypropylene. The advantages of this means are the easily understandable principle and the simply experimental manipulation. More importantly than all of that, the double effects-significant modification effects and high cost performance allow this modification method to be used in industry and engineering universally.Based on the screening of synthetic nucleating agent as the main research idea, and investigated the performance of the three series nucleating agents.Aluminum and titanium as the core atom, aromatic structure of carboxylic acid coordinated with it, is a series of high cost-performance ratio nucleating agent. We prepared aluminum nucleating agents and titanium nucleating agents by different synthesis methods and redefined their modification effects. Seeked to provide a more simple, cleaner research methods.The structurally similar Maleic hydrazide(KMH) and Phthalhydrazide (PHD) were obtained from Maleic anhydride, o-Phthalic anhydride and Hydrazine hydrate. At the same time, examined its nucleation effect.We synthesized three novel anthracene derivatives, the synthesis methods of this new series derivative have been made a preliminary exploration, and we also verified their possibility as the nucleating agents.In this paper, nucleating agents mentioned above were characterized by X-ray diffraction analysis(XRD), differential scanning calorimetry(DSC), Vicat softening temperature(VST) and polarized light microscopy (PLM). The thermogravimetry analysis(TGA) and mechanical properties of iPP were also tested.The results indicated that after changing the synthetic methods, we obtained titanium nucleating agents that combined the previous merits with the better thermal stability and heat resistance. The products of PP/T1 and PP/T2 present not only excellent nucleation effect but also smaller crystal size. In addition, the mechanical properties of them display substantial improvement by comparison with the blank sample. Especially, the tensile strength of PP/T1 and PP/T2 raised respectively by 6.94MPa and 6.69MPa.Aluminium nucleating agents promoted the crystallinity(Xc), the crystallization temperature(Tc) and the crystallization rate of PP effectively. Crystallization effect of A2 being particularly outstanding, the crystallization temperature of PP/A2 rised 17.82℃. With the comparison to the blank sample, the tensile strength of PP/A1 and PP/A2 increased by 8.3% and 19.3%, respectively.The KMH and the PHD were β-form nucleating agents. Namely, both of these nucleators can induce melted polypropylene to crystallize almost entirely into β crystal. The content of β crystal of PP/KMH is higher, which is up to 61%. From the pictures of PLM, we can conclude that the grain size is smaller. Moreover, the impact strength of both PP/KMH and PP/PHD enhanced strikingly, by 93.5% and 184.2% respectively. When the addition of KMH and PHD was 0.3wt%, the tensile strength of PP can respectively reach 39.52MPa and 39.85MPa. Besides, the more the addition of KMH or PHD was, the greater the flexural strength of PP was.Compared with pure PP, the results showed that the impact strength of PP/A is highest among PP/A, PP/B and PP/C, which increased by 140%. This good performance is owing to that A can induce crystal transformation of PP from a crystalline form to β crystalline form. However, the flexural strength and the tensile strength of PP/A, PP/B and PP/C all declined somewhat. Meanwhile, their crystallization temperature and crystallization rate improved in different degrees. The results of TGA indicated that the series of anthracene derivatives could be stably present under the processing temperature of polypropylene, while the VST results stated that the heat-resistance capacity not improved significantly. The mechanical properties of PP/A, PP/B and PP/C are roughly as the same as that of TMA-3.