Study Of The Composite Particle Of Wollastonite Coated By Nano-CaCO₃ And Application Of It In PP

Wollastonite is an important inorganic product of chemical industry, which has been widely used in many industries, such us rubber, plastics, printing, paint and so on. As a whole, wollastonite can made matrix assume strength, thermal stability, wear resistance and small contraction. Because wollastonite assumes bad tenacity and bad impact resistance, it can not be used in many field. To improve this condition, we designed the particle structure of CaCO3-coated wollastonite . In this hierarchy, when the scale of CaCO3 and wollastonite runs to some degree, the toughness of wollastonite will be improved vastly. In the same time, because of nano-CaCO3 coated wollastonite, wollastonite's specific surface area is improved vastly and wollastonite assume much new physics and chemistry performance.In this paper, the crystallization process of nano-CaCO3 was analysed and the process includes chemical reaction stage and nucleation growth stage. In the paper ,the crystallization process was tracked by pH and conductometer. The conclusions was drawn out that under the common condition, the chemical reaction stage was controlled by the absorption of CO2 , which can be determined by pH-time curve, and that the conductivity-time curve can be used to distinguish the nucleation from growth and to judge the end of the carbonization.By the research of influencing factor of coating process, a conclusions was drawn out tha these factors such as temperature, Ca(OH)2 density , CO2 outflow, agitation strength, admixture, had an obvious influce to coating process. Macroscopical physical property of coated material was studied by whiteness machine and specific surface area machine; surface aspect of coated material was figured by optical microscope, SEM, X-Ray Fluorescence, XPS ,IP.PP/wollastonite composite material with different interfacial speciality was produced by the control of surface aspect and the application of couple technique. And we discussed the mechanics influence of CaCO3-coated wollastonite to PP . Coating effect was evaluated through the macroscopical mechanics speciality, and the mechanics speciality of PP/wollastonite composite material was further improved successfully.