Polymer Additives Plasticizers and Flame Retardants

The above mechanistic explanations assume that the plasticizer molecules are not permanently bound to the polymer chains. Since these interactions are relatively weak, there is likely a dynamic adsorption/desorption at various locations among neighboring polymer chains. Accordingly, the plasticizer structure may be fine-tuned to affect its solubility/miscibility with the polymer, as well as its interactions with 

There are two primary reactive modes for flame retardants either gas-phase or solid-state. Since a flame consists of a variety of gas-phase radicals and atoms (Eqs. 6 and 7), a gas-phase flame retardant is one that will scavenge the flame-propagating radicals such as OH and O. In particular, if the hydroxyl radical is suppressed, the exothermic formation of CO2 (Eq. 8) will be prevented thereby reducing the flame temperature. 

The hydrogen halide species behave as flame inhibitors by scavenging hydrogen, hydroxyl and oxygen radicals (Eqs. 11 and 12). 

IMPORTANT MATERIALS APPLICATIONS IV SELF-HEALING POLYMERS 

In general, high molecular weight polymers are typically formed from catalysts derived from early transition metals (Groups 4-6). For late transition metals, the p-hydride elimination mechanism is more preferred, leading to greater numbers of oligomers and dimers. 

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