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‐(N3)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‐(N3)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, 1H‐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.

Aliphatic Polyester/polyhedral Oligomeric Silsesquioxanes Hybrid Networks via Copper‐free 1,3‐dipolar Cycloaddition Click Reaction

“…On the other hand, the octakis-azido POSS was successfully prepared by ring-opening reaction of octakis-glycidyl-POSS with sodium azide according to the literature. [42][43][44][45] The appearance of asymmetric stretching band of azide at 2080 cm −1 as well as disappearance of asymmetric stretching band of glycidyl at 910 cm −1 confirmed the successful transformation of glycidyl groups of POSS to azide functionalities (Fig. 1).…”

“…The FTIR and 13 C‐NMR spectroscopies were utilized to enlighten the structures of the PCA while showing signals at around 1710 and 2120 cm −1 in FTIR spectrum, and 151.6 and 74.5 ppm in 13 C‐NMR spectrum assignable to the CO and CC groups, respectively. On the other hand, the octakis‐azido POSS was successfully prepared by ring‐opening reaction of octakis‐glycidyl‐POSS with sodium azide according to the literature . The appearance of asymmetric stretching band of azide at 2080 cm −1 as well as disappearance of asymmetric stretching band of glycidyl at 910 cm −1 confirmed the successful transformation of glycidyl groups of POSS to azide functionalities (Fig.…”

“…Octakis‐glycidyl‐POSS (EP0409, Hybrid Plastic), and octaisobutyl POSS (MS0825, Hybrid Plastic), 98.0%, Aldrich), 2‐propanol (%98, Acros), acetic acid (%99, Glacidal, Merck), and sodium azide (NaN 3 , 99%, Merck) were used as received. Octakis azido‐POSS (POSS‐N 3 as viscous liquid) was prepared according to the literature . The poly(1,4‐cyclohexanedimethylene acetylene dicarboxylate) (PCA) was synthesized according to our published procedure .…”

“…Octakis azido-POSS (POSS-N 3 as viscous liquid) was prepared according to the literature. [42][43][44][45] The poly(1,4-cyclohexanedimethylene acetylene dicarboxylate) (PCA) was synthesized according to our published procedure. 36 Tetrahydrofuran (THF, %99, Merck) was used without any purification.…”

Halloysite Containing Thermoset Nanocomposites via Free Radical Photocrosslinking Polymerization

“…Polymer nanocomposites can be prepared using various nanoparticles including 1D nanoclays [16] and graphene, [17] 2D carbon, [18] boron nitride [19] or halloysite nanotubes, [20][21][22] and 3D colloidal silica, [23] metal, [24] and POSS nanoparticles. [25][26][27][28][29][30] Numerous investigations have focused on carbon nanotubes (CNTs) and boron nitride nanotubes; both of these materials are technologically demanding to produce in bulk, making them expensive. The halloysite (HNT) is a natural tubular nanostructure composed of silica and alumina similar to kaolinite clay and resembles that of multiwalled CNTs.…”