Synthesis and characterization of new siloxane-modified addition polyimides

✍ Scribed by Paola Laurienzo; Mario Malinconico; Nicoletta Perenze; Anna Laura Segre

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 387 KB
• Volume: 195
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1994.021950905

✦ Synopsis

Abstract

A new series of polyimides was synthesized by addition polymerization of 4,4′‐(bismaleimido)‐diphenylmethane, 1,4‐piperazine and an amino‐terminated polydimethylsiloxane. The synthesis was carried out in m‐cresol solution following a two‐step procedure. Copolymers containing 15 and 20 wt.‐% of the polydimethylsiloxane elastomer were prepared, together with the unmodified base copolymer. Infrared spectroscopy, ^13^C and ^1^H NMR, thermal and thermogravimetric analyses were used to characterize the copolymers. The DSC curves of all the samples showed an exotherm in the temperature range 230–280°C, attributable to curing and addition reactions involving the chain‐end groups. Different glass transition temperatures (T~g~) were observed, depending on the elastomer content. Thermogravimetric analysis indicated that no significant changes occur in the thermal stability of rubber‐modified copolymers.