Kevlar<sup>TM</sup> Fiber-Reinforced Polybenzoxazine Alloys for Ballistic Impact Application
A light weight ballistic composites from KevlarTM-reinforcing fiber having polybenzoxazine (BA)/urethane prepolymer (PU) alloys as a matrix were investigated in this work. The effect of alloy compositions on the ballistic composite properties was determined. The results revealed that the enhancement in the glass transition temperature (Tg) of the KevlarTM-reinforced BA/PU composites compared to that of the KevlarTM-reinforced polybenzoxazine composite was observed. The increase of the elastomeric PU content in the BA/PU alloy resulted in samples with tougher characteristics. The storage modulus of the KevlarTM-reinforced BA/PU composites increased with increasing the mass fraction of polybenzoxazine. A ballistic impact test was also performed on the KevlarTM-reinforced BA/PU composites using a 9 mm handgun. It was found that the optimal contents of PU in the BA/PU alloys should be approximately 20wt%. The extent of the delaminated area and interfacial fracture were observed to change with the varied compositions of the matrix alloys. The appropriate thickness of KevlarTM-reinforced 80/20 BA/PU composite panel was 30 plies and 50 plies to resist the penetration from the ballistic impact equivalent to levels II-A and III-A of NIJ standard. The arrangement of composite panels with the higher stiffness panel at the front side also showed the best efficiency of ballistic penetration resistance.
Authors who publish with Engineering Journal agree to transfer all copyright rights in and to the above work to the Engineering Journal (EJ)'s Editorial Board so that EJ's Editorial Board shall have the right to publish the work for nonprofit use in any media or form. In return, authors retain: (1) all proprietary rights other than copyright; (2) re-use of all or part of the above paper in their other work; (3) right to reproduce or authorize others to reproduce the above paper for authors' personal use or for company use if the source and EJ's copyright notice is indicated, and if the reproduction is not made for the purpose of sale.