One‐Step Method for Synthesis of PDMS‐Based Macroazoinitiators and Block Copolymers from the Initiators

Abstract

Summary: This paper presents a facile one‐step method for the synthesis of macroazoinitiator (MAI) by direct polycondensation of hydroxyalkyl‐terminated polydimethylsiloxane (PDMS) with 4,4′‐azobis‐4‐cyanopentanoic acid (ACPA) under mild conditions. The PDMS‐based MAI was characterized by FTIR, 1H NMR, GPC, and UV spectroscopy, and further used as an initiator for polymerization of methyl methacrylate (MMA) to obtain PMMA‐co‐PDMS block copolymer. TEM observation and DSC analysis demonstrated that the PMMA‐co‐PDMS block copolymer had a microphase‐separated structure.Schematic representation for syntheses of macroazoinitiators (MAI) by the direct polycondensation and corresponding block copolymers.imageSchematic representation for syntheses of macroazoinitiators (MAI) by the direct polycondensation and corresponding block copolymers.

Brush-like poly(ethylene glycol) grafting on SiO2nanoparticles within-situpolymerization

“…N,N′‐dicyclohexylcarbodiimide (DCC) was purchased from Sinopharm Group Chemical Reagent Co., Ltd. and used as received. 4‐(Dimethylamino) pyridinium‐p‐toluenesulfonate (DPTS) was synthesized with 4‐(dimethylamino) pyridine and p‐toluenesulfonic acid . Toluene was dried with 3A molecular sieves before use.…”

Synthesis and properties of triblock copolymers containing PDMS via AGET ATRP

“…Figure 2 showed the FT-IR spectra of difunctional PDMS containing methyl methacrylate end groups (trace a), Br-PDMSBr (trace b), and poly(MMA-b-DMS-b-MMA) (trace c). Trace a and trace b were very similar, they both exhibited the characteristic peaks at 1260 cm -1 (Si-CH 3 ), 1000-1100 cm -1 (Si-O-Si asymmetric stretching vibration), and 800 cm -1 (Si-O asymmetric stretching vibration) from PDMS [22]. Comparing trace a with trace b, unambiguous disappearance of the characteristic peak of C=C at 1635 cm -1 (trace a) and the appearance of the characteristic peak of C-Br at 568 cm -1 (trace b) were observed, this indicated the completion of the direct addition reaction and the successful preparation of the macroinitiator.…”

Icephobicity of polydimethylsiloxane-b-poly(fluorinated acrylate)

“…As seen from Fig. 5, all of the block copolymers demonstrated distinct microphase separation, but the morphologies were different from each other, and strongly dependent upon the PDMS content [15]. The domain sizes caused by the microphase separation on surfaces of PF1, PF2, PF3 and PF4 were 90-200 nm, 50-150 nm, 20-90 nm and 40-65 nm, respectively, decreasing with the reduced PDMS content in the block copolymers.…”