Antistatic behavior

Their relatively high solubility in polymer matrices have led to the use of perchlorate salts as dopants in polymers in order to obtain antistatic behavior. As dopants in polyvinylchloride (PVC) and other chlorine-containing polymers, they improve heat stability and fire retardation characteristics. 

A wide variety of special durable surface treatments have been used on manufactured fibers. These include treatments for imparting such characteristics as soil resistance, antistatic behavior, and wearer comfort through moisture wicking and transport. Fiber finishes also have been used successfully in promoting adhesion between two materials, as, for example, between polyester tire cord and rubber, and between glass fiber and polyester resin. 

The most frequently used properties are well standardized nationally and internationally. Previously, slightly differing standard methods were used for rubbers and plastics, but there has been a trend for them to be combined, with provision made to account for the softer materials. Mostly the methods are a subset from the methods for materials in general, but there are particular procedures for conducting rubbers. For less common properties, general methods are used, and for antistatic behavior there is an increasing number of product tests being introduced. Test procedures are considered in detail in Chapter 25. 

Synthetic fibers do not contain natural impurities although there are added impurities such as sizing materials and oil stains. Therefore, their pretreatment process is simpler than other natural fibers. However, synthetic fibers such as polyester and acrylic have poor wettability, dyeability, and antistatic behavior. After plasma treatment, the fiber surface gets physically altered, and hydrophilic functional groups are introduced to the fiber surface, which improves the wettability of the fiber significantly. In recent years, many researchers have studied ways to modify polyester textile materials, and good results have been obtained (Morent et al., 2008). 

Surface Conductivity. Determining the surface conductivity of the plastic sample is a popular, simple measurement that is often assumed to correlate with antistatic behavior. Practical proof would be more reassuring. 

In using this new approach, conventional corona treatment is combined with injection in a reactive medium of microcapsules in aerosol form. Chemical nanotreatment or coating occurs when the aerosol condenses on the substrate at low temperature, resulting in a durable effect (most likely due to the formation of covalent bonds). An improved antistatic behavior is also obtained on textile substrates. Application is possible on both natural and synthetic fibers, as well as on thermosensitive hydrophobic substrates such as polypropylene and polyethylene. 

Like poly(pyrrole)s, poly(aniline)s show excellent antistatic behavior and have a high shielding efficiency for electromagnetic interference and are useful as anticorrosive... 

During processing, the influence of the spin finishes is mainly observed on the frictional and antistatic behavior. The ability of a spin finish to spread quickly and evenly over the surface of a textile filament or fiber... 

Polyethylene Acrylic acid Hydrophilidly, wettability, antistatic behavior... 

Stabilizers With ionic antistats, it is necessary to avoid reactions with heavy metals that form insoluble salts, such as the use of sulfates with barium or of phosphates with lead. Oxidizing anions such as nitrates should not be used with organophosphitcs or divalent sulfur secondary antioxidants (e.g., DLTDP). As with choice of resin and plasticizer, product and process considerations determine stabilizer selection, and antistatic behavior is usually secondary. 

The use of low-temperature plasticizers in such products enhances antistatic behavior, as does the high level of ESO and addition of EBS. Surface resistivity is lower than with use of more polar plasticizers. The choice of organophosphite for such compounds should reflect plasticizer selection, that is, be of comparable polarity. In FDA-sanctioned compounds, phosphite choice is unfortunately narrow. 

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