Processing and Properties of a Polymer/Composite Double-Layer Laminate

Abstract

Coupled polymer/composite parts were obtained for adapting a bladder-molding technique previously developed for the production of hollow components with continuous fiber-reinforced thermoplastic matrix composites. The internal layer (bladder side) is made up of an unreinforced thermoplastic polymer, linear low-density polyethylene (LLDPE), and the external one (mold side) is made up of a thermoplastic matrix composite based on isotactic polypropylene (PP) and E-glass fabric. The adhesion between the two layers is achieved by applying pressure (<1 bar) through a silicone bladder. The composite/polymer interface was characterized by the evaluation of the interfacial shear strength (IFSS) (between composite and unreinforced polymer), flexural stiffness, and short-beam strength analysis. The experimental mechanical properties were compared with model results, derived on the assumption that perfect adhesion exists between the two layers. A good agreement between the predicted and experimental mechanical properties was observed. As indicated by double notch shear tests used for the IFSS evaluation, good adhesion between LLDPE and PP matrix composite was achieved during processing. The results reported confirm the suitability of the method for a double-layer structure fabrication. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 32: E32–E43, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20267