Optimization of Surface Treatments for Improving Adhesion of UHMWPE Nonwoven Composite with Dissimilar Materials

The ultra-high molecular weight polyethylene (UHMWPE) is one of the lightest weight polymeric material used for ballistic and blast protection. But the difficulty arises when the prepegs of UHMWPE feebly bond with other dissimilar material during hybrid composite fabrication. The effect may be due to its lower surface energy. Many applications including ballistic require higher bond strength of UHMWPE with other dissimilar materials for better interface formation. Therefore, the present study is focused on to identify the suitable surface treatment to maximize the adhesion by minimizing the contact angle for prepeg of UHMWPE (Dyneema HB50). Two different methods, i.e. plasma treatment and acid treatment along with their synergistic effect were studied using contact angle measurement techniques. The chromic acid was selected as chemical etchant and process parameters for plasma treatment were optimized for minimum contact angle measurement so that Dyneema HB50 may form stronger bonds with dissimilar materials during adhesion. This study was also validated by measuring adhesive shear strength of treated Dyneema HB50 composite with Kevlar composite as per ASTM D 5868. The attempt was also made for better understanding of interface through examining morphology using SEM and XPS for better understanding of interface through morphology. It was observed that wettability of plasma-treated Dyneema samples increased and the contact angle reduced significantly more than acid treated samples, which is also validated by the shear strength of Dyneema-Kevlar composite samples. The synergistic effect could not show better result than any of the solitary treatments.