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Detailed understanding of the monomersequence distribution incarbanionic copolymerization was achieved by direct online monitoringof copolymerizations in an NMR tube. Obtaining detailed knowledgeof the changing monomer concentration in stock during the reaction,this technique permits to determine the incorporation probabilityfor each monomer at every position of the polymer chain. An in situkinetic study of two different carbanionic copolymerizations has beencarried out. On the one hand, the copolymerization of the structurallysimilar, protected hydroxystyrene derivatives, p-(1-ethoxy ethoxy)styrene (pEES) and 4-tert-butoxystyrene (tBuOS), and on the other hand thecopolymerization of the chemically different monomers, styrene (S)and pEES, have been studied. Whereas in the firstcase a slight deviation from an ideal random copolymerization wasobserved, the latter copolymerization leads to gradient copolymers.Real-time 1H NMR spectroscopy gave detailed insight intothe reaction behavior at every stage of the copolymerization and leadsto precise understanding of the resulting gradient structures. [ABSTRACT FROM AUTHOR]

The synthesis of diblock as well as gradient copolymers of N,N-diethyl glycidyl amine (DEGA) with ethylene oxide (EO) via anionic ring-opening polymerization is presented. The polymers exhibit low polydispersities (≤1.13) and molecular weights in the range of 3300-10 200 g mol−1. In PEG- co-PDEGA copolymers, incorporation of 4%-29% DEGA results in tailorable cloud point temperatures in aqueous solution and melting points depending on DEGA content. mPEG- b-PDEGA block copolymers can be quaternized to generate cationic double-hydrophilic polyelectrolyte copolymers with polyether backbone. Furthermore, mPEG- b-PDEGA has been used as dual reducing and capping agent for gold nanoparticle synthesis. [ABSTRACT FROM AUTHOR]

Amine-functional poly(ethylene glycol)(PEG) copolymers have beenprepared that exhibit thermo- and pH- responsive behavior in aqueoussolution. Three novel tertiary di(n-alkyl)glycidylaminemonomers have been introduced for anionic ring-opening copolymerization(AROcP) with ethylene oxide (EO): N,N-di(n-butyl)glycidylamine (DButGA), N,N-di(n-hexyl)glycidylamine (DHexGA),and N,N-di(n-octyl)glycidylamine(DOctGA). Via controlled AROcP we synthesized well-defined (Mw/Mn= 1.05–1.14),water-soluble block- and gradient-type PEG copolymers, containingup to 25 mol % of the respective dialkylglycidylamine comonomer. Molecularweights ranged from 4900 to 12 000 g mol–1. Detailed in-situ 1H NMR kinetics and 13Ctriad analyses elucidate the microstructures of the copolymers andthe relative reactivity of the novel comonomers. Notably, the n-alkyl chain length had no significant influence on therelative reactivity of the glycidylamine comonomers. Calculated reactivityratios ranged from rEO= 1.84, rDButGA= 0.49 to rEO= 1.78, rDOctGA= 0.42, manifestingthe formation of gradient copolymers. Thermo- and pH-responsive propertiesof these copolymers are precisely tunable by the comonomer ratio,and cloud points in aqueous solution can be adjusted between 21 and93 °C. Electron paramagnetic resonance (EPR) spectroscopic studieswith TEMPO as a spin probe were conducted to elucidate host–guestinteractions of the copolymers. Unexpectedly, the n-alkyl chain length of the different glycidylamine comonomers onlyinfluences the inverse phase transition of the gradient copolymers,but not of the block copolymers on the nanoscale. Self-assembly ofthe block- and gradient-type copolymers in aqueous alkaline solutionby both static and dynamic light scattering has also been investigatedafter confirming the existence of pure unimers in methanol. [ABSTRACT FROM AUTHOR]