Semifluorinated PMMA Block Copolymers: Synthesis, Nanostructure, and Thin Film Properties

Abstract

Diblock copolymers (BCP) with poly(methyl methacrylate) and poly(1H,1H,2H,2H-perfluorodecyl methacrylate) (PsfMA) blocks prepared by anionic polymerization in tetrahydrofuran at −78 °C and atom transfer radical polymerization (ATRP) at 60 °C, respectively, with stepwise varied composition over a wide range in the phase diagram are compared with respect to synthesis limits, phase separation behavior in bulk, and properties of thin films. Both methods yield BCPs with low dispersity (1.1-1.2) at molar masses below 100 kg mol −1 . Higher semifluorinated contents can be achieved by ATRP in 1,3-bis(trifluoromethyl)benzene which ensured solubility of PsfMA. BCPs obtained by anionic polymerization show a more distinct phase separation, that is, more regular nanostructures. Additionally, self-organization of the semifluorinated side chains occurs generating smectic layers which alters in turn the BCP morphology especially in thin films as compared to non-semifluorinated BCP. All BCPs show amphiphilic behavior and form micelles in organic solvents which can be used to deposit nanoparticles. periodic structures is the low dispersity − D of both blocks in the BCP which can mostly be achieved by employing controlled polymerization conditions. Although more and more methods of controlled polymerizations appear, such as light-controlled polymerization of methacrylates to BCP in a one-pot procedure, [7] visible-light polymerization from hyperbranched poly(methyl methacrylate) macroinitiators catalyzed by Mn 2 (CO) 10 , [8] combination of polymerization and click chemistry, and many others, and taking the variety of BCP syntheses results reported into account, standard techniques for BCP synthesis as anionic polymerization and atom transfer radical polymerization (ATRP) still appear to be the most successful with regards to achieving low dispersity and high control over the structure and molar mass.In this study, we want to compare diblock copolymers with a poly(methyl methacrylate) (PMMA) and a

An in-depth analysis approach enabling precision single chain nanoparticle design

“…Highly PFB decorated precursors are less soluble because of the highly polar C-F bonds, which can alter the overall polarizability and solubility of highly fluorinated polymers. [66][67][68] Excess of the base triethylamine (TEA) served not only to further solubilize the precursor, but also mitigated competitive behavior between the hydroxy endgroup of the precursor and the thiol-groups of the external crosslinker. 53, [69][70][71] Attempts to increase the reaction rate by a stronger base were not successful.…”

“…Such an observation is somewhat expected due to the highly polar C-F bonds decreasing the overall polarizability of multi-fluorinated organic molecules, thus, influencing the refractive index increment dn/dc. [66][67][68] In contrast, sulphur belongs to the group of highly polarizable main group elements and the C-S bond has low polarity. 74 Therefore, the refractive index of the SCNPs is significantly increased due to incorporation of the dithiol-crosslinker.…”

An In-Depth Analysis Approach Enabling Precision Single Chain Nanoparticle Design

“…Highly PFB decorated precursors are less soluble because of the highly polar C-F bonds, which can alter the overall polarizability and solubility of highly fluorinated polymers. [66][67][68] Excess of the base triethylamine (TEA) served not only to further solubilize the precursor, but also mitigated competitive behavior between the hydroxy endgroup of the precursor and the thiol-groups of the external crosslinker. 53,[69][70][71] Attempts to increase the reaction rate by a stronger base were not successful.…”

ATRP of Methyl Acrylate by Continuous Feeding of Activators Giving Polymers with Predictable End-Group Fidelity

“…The retention of polymer end-groups is a critical tool for successful chain extension, post polymerization reactions, and controlling material properties [10,11,12,13,14]. For example, in the synthesis of block copolymers, the lower chain end-group fidelity of the macroinitiators resulted in less regular self-assembled nano-structures [15]. Since the end-group fidelity varies greatly depending on the reaction conditions, the batch-to-batch difference may also hinder industrial applications.…”