Study On The Preparation And Interface Mechanism Of Wollastonite/Polypropylene

Wollastonite is a sort of important inorganic natural mineral. In recent years, the study on enhancement of intensity and toughness of high polymer filled with wollastonite is a heat-researched problem in material science. This paper mainly focused on the study on the preparation of and interface mechanism of wollastonite/polypropylene, a foreland problem in material science. Basing on a lot of experiments, application of various related theories and modern test and analysis means, I have systematically researched the methods and technology of smashing, surface modification of wollastonite and the preparation of wollastonite/ polypropylene. These studies have shown significant results: To protect wollastonite's crystal structure, we can forge and then cool it before fining; Adopting mechanochemical modification by jet mill, we can make wollasonite to fine and modification at the same time; In order to understand thoroughly the major results achieved in enhancement of mechanical capabilities of the polypropylene filled with the modified wollastonite, this paper has researched deeply the interface mechanism through combining experiments and measure means with theory analysis, and tried to give a further explanation and demonstration about improving of the macroscopic mechanics performances of composite material and to offer a theoretical basis for improving material's mechanical properties. Theses studies are new and show some innovation in related material science field.Achieved results as follows:1. In the process of wollastonite fining, we can forge and then cool it to protect its crystal structure which is short acicular fiber. Mechanochemical modification by jet mill is super to speedily mixed modification by stirring mix.2. As to wollastonite, the modification effect using stearic acid is better than that using aluminate ester and silica alkane. The optimum content of stearic acid used to modify wollastonite is 2% of wollastonite weight.3. The mechanical performances of wollastonite/polypropylene have indicated:(1) Wollastonite processed by mechanochemical modification can obviously raise mechanics performances of wollastonite/ polypropylene composite material. Compared with pure polypropylene, the tensile strength is 8.1% higher, the winding strength is 3.6% higher, the breach pounding strength is 86.4% higher and the breaching elongation ratio is 13.1% higher.(2) Considering the effect of wollastonite particle size on performances of composite material, we can find out that, with particle size smaller and smaller, the performances rise at first and then fall.(3) Studying the effect of wollastonite content on performances of composite material, we can find out that the optimum content of wollastonite is 30%, with the content continues to rise, the performances fall accordingly.(4) Compared with other fillers, the performances of wollastonite filling composite system are super to that of calcium carbonate and talcum filling systems, and are near to that of asbestos and glass fiber filling systems.4. The interfacial soaking experiment of wollastonite/ polypropylene composite material has further manifested that the cohesive strength of the interface between modified wollastonite 2 by stearic acid and polypropylene is higher than that of the interface between wollastonite and polypropylene, the interface between modified wollastonite 1 by stearic acid and polypropylene, the interface between modified wollastonite 3 by stearic acid and polypropylene, the interface between modified wollastonite by aluminate ester and polypropylene, the interface between non-modified wollastonite and polypropylene.5. By means of scanning electronic microscope, I have done some observation and researches on the scattering property of wollastonite in polypropylene and the cohesive property between wollastonite and polypropylene. The results have manifested that the scattering property of modified wollastonite 2 by stearic aci...