Additives reinforcing agents

The main analytical or characterization concerns here are not those of natural products or additives, reinforcing agents, or residuals in synthetic... 

The use of inorganic additives as extenders in thermoplastic polymers is a long established practice. In recent years, the role of such additives has changed from that of cost-reducing fillers to property enhancing reinforcing agents. This conversion has come about as a result of the comp tibilization of the additive with the thermoplastic polymer, by interaction at the polymer-filler interface. 

Throughout the text we will relate polymer structure to the properties of the polymer. Polymer properties are related not only to the chemical nature of the polymer, but also to such factors as extent and distribution of crystallinity, distribution of polymer chain lengths, and nature and amount of additives, such as fillers, reinforcing agents, and plasticizers, to mention a few. These factors influence essentially all the polymeric properties to some extent including hardness, flammability, weatherability, chemical stability, biological response, comfort, flex life, moisture retention, appearance, dyeability, softening point, and electrical properties. 

Carbon black is widely used as a reinforcing agent for most synthetic elastomers. It is especially important for synthetic elastomers such as SBR, nitrile rubber (NBR), and BR that do not crystallize at high strains. Thus, non-carbon-filled SBR has a tensile strength of about 2 MPa and with addition of carbon black this increases to about 20 MPa. 

Uses of Fillers, Reinforcing Agents, and Chemical Additives... 

What we are trying to emphasize here is that plastics of themselves are quite functional materials but they can sometimes be made more so through the addition of fillers, reinforcing agents, and chemical additives. Perhaps the most important contribution of fillers is the reduction in cost which they impart. The more expensive reinforcing agents, on the other hand, are used because of the desirable properties they impart to the plastic and such reinforced... 

Since the impact strength characteristics of PVC are insufficient in numerous applications, various solutions have been proposed. All involve blending PVC with an additional resin, but in most cases this causes the disappearance of properties as essential as transparence. For a long time, Pechiney-Saint Gobain has carried out research to produce an addition polymer satisfactory as a reinforcing agent but equally transparent in mixtures with PVC and which does not introduce defects normally encountered with this type of addition (e.g., a white stain on... 

Commercial polymeric materials usually contain a number of additives. Plasticizers, fillers, reinforcing agents, impact modifiers, and crosslinking agents are just a few of the many important types. 

Epoxy resins are not ideal adhesives in their natural form so they are mixed with materials to improve and enhance their properties and, thereby, make them more useful in a variety of applications. This process is called compounding or formulating. Compounding is the combining of a base epoxy resin with curing agents, modifiers, additives, reinforcement, fillers, and other polymers to make the base polymer perform better, cost less, and process more easily. 

---