Surface Modification And Application Of Ground Calcium Carbonate In The Polymers

Ground calcium carbonate(GCC)is one kind of ordinary non-metallic mineral materials.It is widely applied to many industrial areas such as rubber,plastics,coating and so on.Because it has the nature of large specific surface area and high surface energy,it is easy to become agglomerate among particles.When GCC is filled in organic basic body directly or with high quantity,it is difficult to disperse uniformly which results in descent of some properties of composites because of their poor interfacial interaction;and it will affect the performance and quality of present coating when GCC is applied directly to coating.In order to enlarge the application field of GCC,the surface of GCC must be modified to adjust its polarity,descend surface energy and reinforce its compatibility with organic basic body.The dispersibility of GCC into organic basic body and the properties of composites would be improved.This paper reviewed the technologies and trends of surface modification of ultra-fine inorganic powder,Focused on the surface modification principle, modification methods,types of modifier and the application of heavy calcium carbonate in the relevant field.Ground calcium carbonate applied to polyethylene and oil coating was modified respectively with the grafted product of polyethylene wax with maleic anhydride (PEW-MA)and the copolymer of i-octyl acrylate and acrylic acid,the modifiers were synthesized by myself.The technological conditions were optimized and the modification mechanism of ground calcium carbonate was also investigated.The modified effect of GCC was proved by FTIR,TEM,viscosity dispersed in the organic solvent,oil absorption number,wetting contact angle and so on.Ground calcium carbonate applied to water-based coating was modified with the deposition of titanium dioxide and barium sulfate into ground calcium carbonate based on the principle of Liquid Phase Deposition,which was designed by myself. TEM results showed that the experiment was successful,we gained the composite pigment of titanium dioxide,barium sulfate and ground calcium carbonate.In addition, the water-based coating with the composite pigment to replace some titanium dioxide showed good prospects.