Reinforcing agents, additive coloring

Use Accelerator activator, pigment and reinforcing agent in rubber, ointments, pigment and mold-growth inhibitor in paints, UV absorber in plastics, ceramics, floor tile, glass, zinc salts, feed additive, dietary supplement, seed treatment, cosmetics, photoconductor in office copying machines and in color... 

The monomers of both artificial and natural rubber must be polymerized into a three-dimensional network to obtain the finished product. Different processes are used, although they are all quite similar. The process of polymerization (called vulcanization) involves the reaction between rubber isomers and sulfur to produce a polymer with enhanced elasticity and reduced plasticity (Table 4). The reaction between the monomers and sulfur is enhanced by the addition of accelerators and activators. Other chemicals that can be added to both natural and synthetic rubber include retardants, anti-oxidants, curing agents, reinforcers, fillers, ultraviolet inhibitors, softeners/extenders, stabilizers, blowing agents and colorants. Readers are referred to Rubber World Magazine s Blue Book (1997), which extensively surveys the various additives to both natural and synthetic rubbers. Those additives... 

There are thousands of plastic product formulations that are produced in a variety of shapes and sizes, such as solid shapes, films and sheets, foams, molded forms, synthetic fibers, pellets, and powders. They are classified into 30 major groups of plastics and polymers. In addition, most finished products contain additives such as colorants, reinforcing agents, fillers, stabilizers, and lubricants. These additives vary the chemical nature of the product still more. 

Subsequently, innumerable efforts, both formal and informal, have been directed to the further improvement of a more technical definition. Part of the difficulty encountered lies in the manner in which elastomers find their way to use as end items. While additives, such as stabilizers, coloring agents, and reinforcing agents, are utilized in various combinations with polymeric materials formed into fibers and various plastics, many of these polymer forms have significant value in essentially unmodified form. Polystyrene and polymethyl methacrylate is examples of thermoplastics of this type, and nylons (polyamides) and rayons (cellulosics) are examples of fibers. In contrast, rubber polymers rarely find use as end items without substantial modification. 

There are thousands of chemical species used as additives, namely antioxidants, metal deactivators, flame retardants, colorants, plasticizers, impact modifiers, lubricants, fungicides, bio-stabilizers, nucleating agents, antistatic agents, crosslinkers, etc. In addition, there are contaminants left after polymerization, compounding or foaming processes. Ideally, the additives should be miscible with the polymer they are supposed to reinforce, protect or color. However, thermodynamics requires that the low molecular... 

The metal fillers act as a reinforcing material that results in added strength and stiffness (126). They color the plastic gray for nickel, 2inc, stainless steel, and aluminum, and brown for copper. Metal additives are more expensive than carbon black or surface-active agents, but they get extensive use in EMI shielding appHcations. 

Reinforced plastics may also include fillers (qv), which are inexpensive materials such as calcium carbonate used to displace resin and reduce cost curing agents (catalysts), promoters, inhibitors, and accelerators, which affect thermosetting resin cure colorants release agents (qv) to facilitate removal from the mold and other additives which can impart a wide variety of properties to the finished part, such as fire resistance, electrical conductivity, static dissipation, and ultraviolet resistance. 

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