Gradient copolymers by atom transfer radical copolymerization

Statistical copolymers of 2‐(trimethylsilyloxy)ethyl methacrylate and methyl methacrylate synthesized by ATRP

“…1 H NMR spectra of 10% (w/w) solutions in THF-d 4 or dimethyl sulfoxide-d 6 were measured at 330 K with a Bruker Avance DPX300 spectrometer at 300.13 and 75.45 MHz resonance frequencies, respectively. The nuclear magnetic resonance (NMR) spectra were collected in a quadrature mode.…”

“…As a result, all growing chains have approximately equal instantaneous composition, which depends only on the relative concentrations of monomers in the reaction and on their reactivity ratios. Copolymerization of two monomers by ATRP produces statistical copolymers having a gradient in chemical composition along the chain; 4 the steepness of the compositional gradient is governed by the difference in monomer reactivity ratios. Generally, there are two types of gradient copolymers that can be prepared by ATRP or by other controlled radical polymerization methods.…”

Calorimetric study of block-copolymers of poly(n-butyl acrylate) and gradient poly(n-butyl acrylate-co-methyl methacrylate)

“…These atypical interactions are expected to result in unique thermal properties for the gradient copolymers. Up to date, the most change in the properties of the block copolymers separation into macrophases of the chemically different, immiscible components is restricted in the block copolymer, actions however, only few and qualitative publications are available which report on thermal analysis of gradient copolymers [11,12]. In the present work we use conventional, quantitative DSC methods to study miscibility and phase separation based on heat capacity and glass transition temperatures for a series of diblock and triblock copolymers of poly(butyl acrylate) and gradient copolymers of butyl acrylate and methyl methacrylate with different compositions.…”

Sequence-controlled polymers via reversible-deactivation radical polymerization

“…However, when one monomer is gradually added into the polymerization of another monomer, there is a big difference in the resultant composition distribution between RDRP and free radical polymerization: a gradient sequence can be obtained in the former under the control of the addition speed, whereas a mixture of chains with various composition ratios was observed in the latter case (Figure 4a). 23 The intentional control of the existing comonomer concentration for the RDRP process without irreversible deactivation of the growing end allows a uniform sequence between resultant chains.…”