Syntheses Of Polyether-containing Titanate And Research Of Its Toughening Polyolefin

In this paper, a new titanate coupling agent, the isopropyl tris- (polyether-isooctylpyrophosphato) titanate was prepared by reaction of polyether and isooctanol withP2O5 and the reaction of the middle produce with isopropyl titanate. The effects of themixture ratio, reaction temperature and molecular weight of polyether on the first stepreaction were investigated. The results show that the percent conversion increaseswith the increase of the isooctanol content in mixture and the reaction temperature.the suitable temperature of the reaction is 60℃~90℃. The reaction is more easilytaken place when the molecular of the polyether is decreased and the activity of thefunctional group of the polyether is increased. The coupling agent on the mechanical properties of HDPE/CaCO3,PP/POE/CaCO3 and PVC/CPE/CaCO3 blends were investigated by means of SEMand mechanical properties measurement. The results show that the impact strengthand flexural modulus of HDPE/CaCO3, and PP/POE/CaCO3 blends were obviouslyenhanced and the impact strength of PVC/CPE/CaCO3 blends was also obviouslyimproved by using the CaCO3 particles, which were surface-treated with the couplingagent. The effects of the cooling shrinkage stress and the melt flow orientation in thePP/POE/CaCO3 blends injection molding process on the Charpy notched impactstrength of testing bar were investigated. The results show that cooling shrinkagestress coming from the blends molding process can cause cracking of the interfaciallayer of 10 mm thick testing bar, and lead to obviously decrease of the impact strengthof the blends. The melt flow orientation coming from the blends injection moldingprocess can lead to obviously increase of the impact strength of the 4 mm thick testingbar. The studying on the crystallization kinetics of PP/POE/CaCO3 blends shows thatthe cooling shrinkage stress can accelerate crystallization of the matrix, and obviously iincrease the crystallization enthalpy ΔHC, the crystallization growth index n and therate constant of crystallization growth k. When the CaCO3 content is 30%, ΔHC andn reach to maximum. The accelerating crystallization action has a best condition,when cooling rate a is 5℃/min, the amplitude of ΔHC and n reach to maximum. The TEM photomicrographs indicated that the PP/POE/CaCO3 blends have ahigher interfacial adhesion and good compatibility, the interfacial stress coming fromthe blends molding process results in the strain induced crystallization in the dispersedelastics particles.