Ngoài chất độn than đen với chức năng chính là gia cường cho cao su, nhiều loại chất độn khác cũng được phối trộn với cao su có các chức năng khác nhau như gia cường, làm giảm chi phí sản phẩm và giúp sản phẩm có những tính chất đặc biệt. Phần tài liệu sau đây sẽ trình bày tổng quan về phân loại và tính năng của các chất độn khác than đen này.

…

A wide variety of non-black fillers for rubber exist. Today, the principal non-black fillers are clays, precipitated silicas and calcium carbonates. Other major fillers include mica, talc, zinc oxide, magnesium carbonate, magnesium oxide, titanium oxide, barites and many others. Short fibres of aramid, carbon, glass, nylon or polyester, are also widely used in rubber compounds. It will be impossible to discuss all of these non-black fillers within a single chapter. Therefore, the discussion will describe some non-black fillers, and will also examine differences between reinforcing mechanisms of the non-black fillers and carbon black. Non-black fillers can be classified in three categories by their function in rubber. Non-black fillers of the first category are called reinforcing pigments. They include precipitated silica, fine particle size precipitated calcium carbonate, and perhaps hard clay with surface treatment. Note that they all have very fine particle size, less than 1 μm, especially to add high strength to synthetic rubbers. Non-black fillers of the second category are called diluents. In practice, they are used to reduce cost of the compound. Soft clay, ground calcium carbonate, talc and barytes fall into this category. They are all considered inert fillers and sometimes can be used at loadings as high as 200 phr, without significantly increasing the modulus of the compound. Usually this family of filler reduces compound die swell and provides sharp-edged extrudates and smooth calendering behaviour in the rubber manufacturing process. The third category of non-black filler consists of materials that add special traits to the compound, for example, colour, electrical conductivity, flame resistance, impermeability, or oil resistance characteristics. All of these traits depend on the particle size, structure, shape and surface chemistry of the filler when compounded into rubber.

…

Trích đăng từ sách Rubber Technologist’s Handbook, Sadhan K. De và Jim R. White, Smithers Rapra Technology, 2001, trang 155 – 157

Nguồn: www.books.google.com.vn

(vtp-vlab-caosuviet)