PULTRUDED FIBER-REINFORCED PMMA PU IPN COMPOSITES - PROCESSABILITY AND MECHANICAL-PROPERTIES/

This paper presents a proprietary process developed to manufacture pol y(methyl methacrylate) (PMMA)/polyurethane (PU) interpenetrating polym er network (IPN) pultruded composites. The IPN prepolymer was prepared from blends of MMA prepolymer and blocked NCO-terminated PU prepolyme r. The processability, mechanical and dynamic mechanical properties of glass fibre-reinforced PMMA/PU IPN composites have been studied. From the investigation of the pot life of the resin, the reactivity of the resin and fibre wet-out, it was found that the PMMA/PU IPN shows exce llent processability for pultrusion. Results show that the tan delta o f the IPN composite shifts to a higher temperature with increasing PMM A content and that the dynamic shear storage modulus (G') increases wi th PMMA content. The flexural strength, flexural modulus and hardness of IPN composites increase with PMMA content. However, the impact stre ngth and swelling ratio of IPN composites decrease with increasing PMM A content. Copyright (C) 1996 Elsevier Science Limited.