Bondability index

FIGURE 16.6 Bondability index of common and specialty elastomers.79... 

The first rule is to use the easiest-to-bond type of rubber that will provide the required service performance of the part. In general, there is a hierarchy among rubber types which ranks them according to their ability to be bonded with adhesives. This hierarchy is called the bondability index [4]. What causes differences in bondability is still a matter of debate. It has been attributed to differences in polarity, chemical reactivity, solubility and molecular symmetry between the different available classes of rubbers [4]. Regardless of the cause, the bondability of general purpose rubbers is ranked as follows ... 

Many times, the choice of rubber is dictated by the service requirements of the part. Even within classes of rubbers, there are different degrees of bondability based on the specific polymer chosen and depending on the rest of the ingredients in the formulation. Nevertheless, the bondability index shows the relative ease of bonding certain classes of rubbers. 

TF1V has a unique combination of properties that include relatively low processing temperatures, bondability (to itself and other substrates), high flexibility, excellent clarity, low refractive index, and efficient electron-beam cross-linking.91 It also exhibits properties associated with fluoroplastics, namely, very good chemical resistance, weatherability, low friction, and low flammability. Typical properties of the dry grades are summarized in Table 3.9 and those of THV in aqueous dispersion form in Table 3.10. 

Features Flexible transparent hydrophobic coprocessable with oletinic plastics, hydrocarbon elastomers processes at relatively low temps. exc. chem. resist. bondable to itself and other substrates Properties Pellets or agglomerate melt flow index 15 (265 C, 5 kg) sp.gr. 

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