Twenty semicrystalline polyimides based on well-known aromatic dianhydrides and aliphatic ct,(o-diamines have been synthesized and characterized. Poly(BTDA-DAB) synthesized in a two-step process from 3,Y,4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and 1,4-diaminobutane (DAB) exhibits a rather exclusive balance between thermal/mechanical properties and processability. In the series of ct, co-diamines and BTDA the glass transition temperature (Tg) increases linearly with the decrease in CH 2 units, while the melting temperature (Tin) shows the well-known odd-even effect. For the as-synthesized poly(BTDADAB) Tg and T,, are 175 and 277°C, respectively. After melt processing a sharp decrease in crystallinity is observed with X-ray and d.s.c., however annealing of injection moulded test bars results in a higher crystallinity. The semicrystalline poly(BTDA-DAB) exhibits interesting mechanical properties, e.g. a G' modulus of 1.7 kN mm- 2 and an Izod impact of 3.4 kJ m- 2.
Посилання на статтю:
Synthesis and properties of a, w -diarninoalkane based polyimides / Cor Koning*, Liliane Teuwen, E. W. Meijer and Joost Moonen // Polymer. – 1994. – Vol 35. – P. 4889-4895.