Effect of crosslink density and internetwork grafting on the transparency of polyurethane/polystyrene interpenetrating polymer networks

✍ Scribed by V. Nevissas; J. M. Widmaier; G. C. Meyer

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 426 KB
• Volume: 36
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1988.070360616

✦ Synopsis

Because of their incompatibility and the different refractive indices of the homopolymer components, polyurethane/polystyrene interpenetrating polymer networks are turbid by nature. Different parameters likely to enhance their transparency are examined: the crosslink density of each network and the level of internetwork grafting. The results prove that the latter factor is the most effective, as in some cases, very clear and transparent samples are obtained. Correspondingly, preliminary investigations of the dynamic mechanical properties show an inward shift of the glass transition temperatures for such systems. It is concluded that parameters able to cause a higher degree of phase dispersion can yield transparent materials.