Study On Properties Of Polymer/Anhydrite Composites

The study of the anhydrite which had been used as the polymer filler was few in china and fremdness. The author discovered that, the anhydrite is a kind of outstanding polymer fillers from the massive experimental data.There are four big contents in this paper.(1) The anhydrite was modified by the stearic acid, the aluminium coupling agent and the titanate coupling agent A and B. The modifiers were used solely or together. The results showed that the titanate coupling agent A was the best modifier when the dosage was 1.5% of the anhydrite and all the modifiers were combined to the surface of anhydrite through the chemical bond besides the physical cladding. The modification mechanisms were studied in the paper.(2) The anhydrite was used in PVC. The results showed that the anhydrite was possible to apply in the PVC shapes after the reasonable modification.(3) The mechanical performance, the rheological behavior and the crystal characteristic of PP and PP/anhydrite composites were studied. The results showed that the anhydrite could toughen and reinforce PP. The anhydrite modified by the aluminium coupling agent had the better effect than that of modified by the stearic acid and the borate ester coupling agent, which could increase the tensile strength of PP composites greatly.The PP/anhydrite composites were the typical pseudo-plastic fluid. The anhydrite caused the size of PP spherulite diminish and caused the quantity increase.But the crystallographic form did not changed, and the modifiers did not change the PP spherulite size and the crystallographic form, too.(4) The non-isothermal crystallization kinetics and crystallization behavior of PP and PP/anhydrite composites were investigated by means of DSC.The results showed that the anhydrite could be used as the heterogeneous nucleating agent. The anhydrite caused the nucleation fashion and growth fashion of polypropylene spherulite chang. The modifiers did not change the heterogeneous nucleation of PP. The anhydrite increased the rate of crystallization. In the similar rate of cooling and the same anhydrite packing quantity, the anhydrite modified by modifier could increase the crystallization rate of PP , which was faster than that of unmodified, but the different modifiers had the different influences.