Star-shaped hybrid polymers as insulators for organic field effect transistors

Abstract

Synthesis of star-shaped polystyrene (PS) and poly (methyl metachrylate) (PMMA) containing a polyhedral oligomeric silsesquioxane (POSS) core are fabricated by combination of atom transfer radical polymerization (ATRP) and copper (I) catalyzed azide-alkyne cycloaddition (CuAAC) click reaction techniques. The synthetic route proceeds in two steps; firstly, clickable alkyne-end functionalized polymeric arms and a POSS-(N-3)(8) core are prepared independently by arm-first approach using ATRP and nucleophilic substitution reaction of octa-(3-chloropropyl) silsesquioxane POSS-(Cl)(8) with sodium azide. Finally, the CuAAC click reactions between inorganic-organic hybrid core POSS-(N-3)(8) and alkyne functionalized PMMA and PS arms provide the targeted star-shaped polymers. Their chemical structures and molecular characteristics are clearly confirmed by FT-IR, H-1-NMR, and GPC analyses. The obtained polymers are utilized as insulators for organic field effect transistors (OFETs) using perylene as an active n-type organic semiconductor. Compared with linear PMMA and PMMA-POSS, the POSS-(PMMA)(8) exhibited better output and transfer characteristics for the OFET device.