ABSTRACT
Natural rubber is the ingredient common to all self-seal adhesives. It is this raw material, generally utilized in the latex form, which confers or facilitates the ability to cohere.
Natural latex consists of long chain, high molecular weight molecules, the ends of which are thought to contain an extra double bond protected with a weak hydrogen-bonded protein molecule. It is believed that when such molecules are positioned in intimate contact and mechanical or thermal energy is introduced, the following reaction takes place. First, the weakly hydrogen-bonded protein molecule breaks from the long chain and second, stored elastic energy from within the molecule is released, causing molecular vibration. The subsequent entanglement of the chains and joining at the now-available bonding sites produces a molecular inseparable condition referred to as a cohesive seal (Figure 50.1, Figure 50.2, and Figure 50.3).
