Stress–strain properties and thermal resistance of polyurethane–polyepoxide interpenetrating polymer networks

✍ Scribed by K. C. Frisch; D. Klempner; S. K. Mukherjee; H. L. Frisch

• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 435 KB
• Volume: 18
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1974.070180307

✦ Synopsis

Two-component interpenetrating polymer metworks (IPN) of the SIN type (simultaneous interpenetrating networks) were prepared from three different polyurethanes and two epoxies. The linear prepolymers were combined in solution, together with crosslinking agents and catalysts, films cast, and subsequently chain extended and crosslinked in situ. Two of the IPN's showed significant improvement in thermal resistance, as measured by thermogravimetric analysis (TGA). All of the IPN's showed maxima in tensile strength significantly higher than the tensile strengths of the component networks at 25% polyurethane and minima at 75y0 polyurethane. The minima were explained by an initial dilution of the strong polyurethane hydrogen bonds by the epoxies, and the maxima, by an increase in crosslink density due to interpenetration.