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E. Hałasa

Synthesis of polyimides from poly(amic acids) and their esters

Polimery 2005, No 1, 20



Summary

Methods of synthesis and general characteristics of polyimides (PI) prepared with use of poly(amic acids) (PAmA), poly(amic acids' alkyl diesters) (PAmE) or oligoimides containing nonbornene groups (PMR-15) as prepolymers. Criterion of usefulness of these prepolymers to the further processing is hydrolytic stability increasing this way: PAmA < PAmE < PMR-15. Dependence of mechanical properties (elongation at break, tensile modulus, stress at break, tensile strength) on molecular weight of prepolymer has been also discussed. It has been found that optimal PI properties were reached when prepolymers of Mw in the range 30 000-80 000 were used to imidization. Additionally PI applications dependently on the oligomers used for their preparations were described. Special attention was paid to prepolymers showing the highest hydrolytic stability - PMR-15. Because of end unsaturated bonds they can undergo crosslinking, what give them character of hardening plastics. Mechanisms of these compounds' synthesis were presented.


Key words: poly(amic acids), poly(amic acids' alkyl diesters), oligoimides containing nonbornene groups, hydrolytic stability, synthesis, polyimides, mechanical properties


E. Hałasa

Synthesis of polyimides from poly(amic acids) and their esters