The Study On Sub-Cluster Statistics Theory About The Dynamic Mechanical Properties Of The Highly Reflective Solar Sails Thin Film Of Polyimide

In recent years, the solar sail turn into a new research of space propulsion. Surface-silvered polyimide (PI) film is the preferred material for preparation of a solar sail. So, preparation of Surface-silvered polyimide (PI) film has become a current research focus.Based on polyimide-based composite film of silver curve of the DMTA data, the sub-cluster parameters K, R1, R2 of the PMDA/ODA-based,PMDA-ODPA/ODA-based,BTDA/ODA-based and ODPA/ODA-based polyimide composite film of silver were obtained, by the calculation using JRG sub-cluster statistics theory in this paper. We obtain the following results:to the PMDA/ODA-based polyimide composite film of silver, with the chain segment distributed well, the strength of this polymer is decreased; but the reflectance is raised. So, we must look for a equilibrium point of segment distribution.To the BTDA/ODA-based polyimide composite film of silver, strength and modulus increase with the chain segment distributed well and the reflectance high. We must improve uniformity of sequence distribution. To the ODPA/ODA-based polyimide composite film of silver, chain segment distributed well lead to the low strength of polymer and poor mechanical properties and reflectivity. Therefore, we have to reduce the evenness. To the PMDA-ODPA/ODA-based film, random polymer has the low reflectivity,but in block copolymer reflectivity and performance are well. The relationship between R1R2/K and dynamic mechanical properties of thin-film was examined, which could serve as a theoretical guidance for future experiments in a certain degree.