Polypropylene Impregnation Improvement into Glass Fiber Woven Roving by In-Situ Polymerization

ETCHEVERRY, MARIANA; FERREIRA, MARÍA LUJÁN; CAPIATI, NUMA JOSÉ; BARBOSA, SILVIA ELENA

San Sebastián, España

Conferencia; V International Conference on Science and Technology of Composite Materials COMAT´09; 2009

Universidad del País Vasco

The adhesion between matrix and fibers is an essential factor in the final performance of thermoplastic-based polymer composite materials. The interfacial adhesion of the polypropylene (PP) and glass fibers (GF) can be highly improved by chemical anchoring between PP and GF. The use of thermoplastics in high performance composites, is not large because polymer high viscosity that impedes the impregnation in mats or woven fibers. In this sense, direct polymerization also enhances the infiltration because the polymer is formed in-situ from a gas. In this work, a methodology for direct polymerization of PP onto GF is proposed. The reaction route includes an initial contact with methylaluminoxane (MAO) and hydroxy-a-olefin to generate the anchorage points on the fiber surface, followed by a propylene polymerization catalyzed by EtInd2ZrCl2 (metallocene)/MAO. As a result of this reaction, PP chains grow by copolymerization of propylene with the olefin anchored to the GF surface. This procedure was carried out either on continuous strand or on woven roving. The PP/GF adhesion, as well as, the PP impregnation was characterized by Scanning Electron Microscopy (SEM) with X-ray Disperse Energy Microanalysis on line (SEM/EDX) on cryogenic fracture surfaces. All properties were so improved, fiber surface change their character from hydrophilic to hydrophobic, then surface adhesion was duplicated, and resin infiltration is so enhanced.