Visualization and design of the functional group distribution during statistical copolymerization

Even though functional copolymers with a low percentage of functional comonomer units (up to 20 mol%) are widely used, for instance for the development of polymer therapeutics and hydrogels, insights in the functional group distribution over the actual chains are lacking and the average composition is conventionally used to describe the functionalization degree. Here we report the visualization of the monomer distribution over the different polymer chains by a synergetic combination of experimental and theoretical analysis aiming at the construction of functionality-chain length distributions (FUNC-CLDs). A successful design of the chemical structure of the comonomer pair, the initial functional comonomer amount (13 mol%), and the temperature (100 °C) is performed to tune the FUNC-CLD of copoly(2-oxazoline)s toward high functionalization degree for both low (100) and high (400) target degrees of polymerization. The proposed research strategy is generic and extendable to a broad range of copolymerization chemistries, including reversible deactivation radical polymerization.

Facile synthesis of well-controlled poly(glycidyl methacrylate) and its block copolymers via SARA ATRP at room temperature

The detailed synthesis of poly(glycidyl methacrylate) (PGMA) by atom transfer radical polymerization (ATRP) using a catalytic system of Fe(0)/Cu(ii)Br₂ at room temperature is reported.

Zero valent metal/RAFT agent mediated CRP of functional monomers at room temperature: a promising catalyst system for CRP

A facile approach to synthesize GMA polymers using Fe(0)/RAFT agent mediated control radical polymerization.

Copper mediated controlled radical copolymerization of styrene and 2-ethylhexyl acrylate and determination of their reactivity ratios

Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA) and styrene using copper bromide (CuBr) as catalyst in combination with N,N,N′,N″,N″- pentamethyldiethylenetriamine (PMDETA) as ligand and 1-phenylethyl bromide (PEBr) as initiator. Linear kinetic plot and linear increase in molecular weights vs. conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using ¹H NMR studies. The reactivity ratio of styrene and EHA (r₁ and r₂) were determined using the Finemann–Ross (FR), inverted Finemann–Ross (IFR), and Kelen–Tudos (KT) methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis.

Biomimetic surface modification of honeycomb films via a "grafting from" approach

Hydrophobic isoporous membranes were fabricated using the "breath figure" method from polystyrene stars synthesized via ATRP. The living polymer chain ends at the surface of the films were then used, without further modification, in a "grafting-from" approach to grow surface-linked polyglycidyl methacrylate chains under conditions that maintained the regular honeycomb structure. This versatile functional surface was then used as a platform to build a small library of surfaces using a variety of simple chemistries: (i) the acid hydrolysis of the epoxide to form bis-alcohol groups and (ii) utilizing the "click-like" epoxide-amine reaction to functionalize the surface with a model biomolecule-(biotinamido)pentylamine. The successful modifications were confirmed by a combination of spectroscopic and biological means. Changes in the growth characteristics of nonmotile Psychrobacter sp. strain, SW5, on the honeycomb films, provided further evidence confirming changes in the hydrophobicity of the surface upon grafting.