THE ADHESION PROPERTIES OF AN OZONE MODIFIED THERMOPLASTIC OLEFIN ELASTOMER

The adhesion properties of a thermoplastic olefin elastomer (TPO) afte r ozone exposure are studied with attenuated total reflection infrared spectroscopy (ATR), the lap shear test, and contact angle measurement . The ozone treatment is applied after the TPO is dip-coated with acry lic acid (AA) that is mixed with benzophenone, benzoyl peroxide (BPO), and azobisisobutyronitrile initiators. ATR spectra confirm the presen ce of grafted AA on TPO, the amount of which depends on the ozone expo sure lime and the type of initiator applied. The total surface energy, the polar component, and lap shear strength (LSS) of the grafted TPO increase with increasing ozone exposure time and also vary with the in itiator. All AA-grafted TPOs have much greater LSS than the TPO withou t AA. The greatest LSS is obtained from the specimen grafted with AA a nd BPO. In addition, the small differences in surface energies and fai lure strains associated with the great changes in LSS obtained from va rious specimens implies that the nature of the grafted layer has a sig nificant effect on the adhesion strength.