Block polymers from isocyanate-terminated intermediates. IV. Properties of cured butadiene–ε-caprolactam block polymers

✍ Scribed by William L. Hergenrother; Richard J. Ambrose

• Publisher: John Wiley and Sons
• Year: 1975
• Tongue: English
• Weight: 461 KB
• Volume: 19
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1975.070191209

✦ Synopsis

Abstract

Butadiene–ε‐caprolactam block polymers containing a high proporation of 1,2 units in the butadiene‐segments were synthesized and physical properties were measured on the cured copolymers. Flexural strength and impact resistance both increase regularly with increasing ε‐caprolactam content in peroxide cured copolymers. This behavior is explained by the higher values of flexural modulus and impact resistance for poly(ε‐caprolactam) compared with peroxide‐cured polybutadiene resins. Copolymers reinforced with silica showed higher heat distortion temperatures but lower impact resistance than corresponding unfilled samples. Arrhenius plots of flexural properties at various test temperatures were linear. Both flexural modulus and strength decreased regularly with increasing test temperature. Flexural properties of filled copolymers were relatively unaffected by heat aging up to 204°C for several weeks, however, dramatic decreases in these properties were noted in a matter of days when heat aging was done at 260–316°C. These results are explained by the rapid degradation of poly(ε‐caprolactam) above its melting point. Block polymers whose butadiene segments contained a high proportion of 1,4 units were also synthesized. These copolymers were elastomeric when cured with either sulfur or peroxide.