Effect of Interlayer on Impact Resistance of Acrylic/Polycarbonate Laminates,

摘要

Acrylic/polycarbonate laminates for aircraft windshield applications fabricated using transparent flexible polyurethane adhesive interlayers have demonstrated ballistic resistance up to forty-five percent greater than polycarbonate,currently considered the best commercially available transparent impact-resistant material. Optical and transmission electron microscopy show that the translucent and opaque materials have spherulitic structures which are few in numbers at low 'hard'segment concentration and densely packed at high concentration. So long as the materials showed no spherulitic structure,no real variation in ballistic performance was found with increasing 'hard'segment. The mode of failure of these laminates was ductile contrary to thermally bonded laminates or laminates using a brittle adhesive,thereby eliminating the spallation problem inherent in the use of monolithic acrylic windshields. Thus,as long as spherulitic formation can be prevented,the ballistic resistance of polyurethane interlayered plastic laminates is superior to all other transparent plastic systems (polymethyl methocrylate).