SYNTHESIS AND PROPERTIES OF SULFUR-HETEROCYCLIC-BRIDGEDPOLYIMIDES WITH HIGH REFRACTIVE INDEX
含硫杂环桥联的高折射率聚酰亚胺的合成与性能

A series of modified polyimides(PIs)exhibiting refractive indices higher than 1.74 were developed by the introduction of sulfur-containing moieties.First,two sulfur-heterocyclic-bridged diamines,2,5-bis(4-aminophenylenesulfanyl)thiophene(APST)and 2,5-bis(4-aminophenylenesulfanyl)-1,3,4-thiadiazole(BATT)were synthesized.The two diamines were polymerized with a sulfur-containing dianhydride 4,4'-p-thiobis(phenylenesulfanyl)] diphthalic anhydride(3SDEA)respectively via a two-step polymerization procedure to a...