Effects of flaming on polypropylene long glass fiber composites for automotive bonding applications with polyurethane

Flaming treatments have been used for many years in the automotive industry to improve chemical affinity of polymers such as polypropylene with coatings. This study focuses on adhesion a specific bonded assembly: methane-flamed long glass fiber (PPGFL) substrate two-component polyurethane (PU) adhesive. The effects flaming treatment, specifically equivalence ratio R and exposure time t, are evaluated. surface morphological modifications PPGFL caused by treatment linked mechanical properties assembly. Goniometer X-ray photoelectron spectroscopy analyses reveal that atomic percentage grafted oxygen were at maximum slightly reducing mode: = 1.06 t 25 ms. In addition, force microscopy observations show nodular structures formed under these conditions, confirming greater oxidation. These results consistent characterizations compared those obtained after aging. Based previous results, model is proposed. model, well known reaction mechanisms adhesive, allows us highlight particular group plays an essential role PPGFL/PU system.