Scratch Resistant Polyimide Coatings for Aluminosilicate Glass Surfaces

摘要

Several polyimide resins were tested as possible scratch resistant coatings for aluminosilicate glass centrifuge tubes, Tubes with siloxane pretreatments provided the best adheion between the polyimide and glass surface. Resins synthesized with on alkoxysilane group incorporated into the polyimide chain also showed improved adhesion , but the results were not as significant as when the pretreatment was used. Elastic recovery and effective Young's modulus of the polyimide coatings were calculated from nano-scratching .The results inicate that polyimides with a lower modulus, and higher elastic recovery , protected the glass surface best, exhibiting compression of the coating layer. An example was ploy-4-4'-oxydiphenylene pyromellitimide (PMDA-ODA), wheres the coatings with a high effective Young's modulus and low elastic recovery ruptured.An example of a failed coating was poly-4,-4'-carbonyldiphenylene 3,3'4,4'-biphenylenetetracarboximide (BPDA-DAPB)which had low amount of elastic recovery , high effective Yong's modulus and a large amount of flaking during macroscratch testing