Bicomponent nanophase-separated poly(2-hydroxyethyl methacrylate)-linked-polyisobutylene (PHEMA-l-PIB) amphiphilic conetworks were synthesized by radical copolymerization of methacrylate−telechelic polyisobutylene (MA−PIB−MA) and different amounts of 2-(trimethylsilyloxy)ethyl methacrylate (SEMA) followed by quantitative hydrolysis of the trimethylsilyl protecting groups. The PIB content of the resulting conetworks, determined by elemental analysis and solid-state 1H NMR under fast magic-angle spinning (MAS), varied between 17 and 63% w/w. Phase separation and morphology of these conetworks were investigated by DSC, small-angle X-ray scattering (SAXS), and for the first time by 1H spin diffusion solid-state NMR. Two T g values were observed by DSC in all samples. The observed T g values were close to the literature values of both homopolymers (110 °C for PHEMA and −67 °C for PIB), indicating a strong phase-separated morphology in these conetworks. Parameters were optimized for the 1H spin diffusion NMR experiments, and the measurements were carried out with six filtering cycles and a 10 μs delay between pulses at 90 °C. The NMR and SAXS measurements prove strong phase-separated morphology. The sizes of the hydrophilic (PHEMA) and hydrophobic (PIB) nanodomains were determined to be in the 5−15 nm range. The spin diffusion experiments also indicate strongly separated phases without a detectable interface with mixed components. The long period of our system seems to depend weakly on the volume fraction whereas the morphology of the nanophases depends on the volume fraction.

The effect of annealing PVDF at temperatures above T g and below T m was investigated by differential scanning calorimetry (DSC), thermostimulated current spectroscopy (TSC) and solidstate NMR. This study evidences a progressive structural evolution, taking place during such annealing. Its characteristics (kinetics and its temperature dependence, lack of reversibility at lower temperature over extended periods of time, double organization corresponding to double annealing with unmodified kinetics) point to a mechanism of secondary crystallization as described by Marand et al. In addition to the formation of extra crystalline (hence rigid) material, this phenomenon is believed to generate increasing conformational constraints in the residual amorphous material. Accordingly, a progressive reduction of the molecular mobility was demonstrated by NMR during annealing.

SUMMARY: A collection of high resolution solid-state 13 C NMR spectra was recorded in a standard way employing cross polarization (CP), magic angle spinning (MAS), and high power proton decoupling. The collection will be useful for reference purposes in case of unknown or partly unknown samples such as polymer blends, block copolymers, or polymeric latexes. The collection is available via internet at

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Articles you may be interested inNuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-estersulfonate ionomers J. Chem. Phys. 136, 014510 (2012); 10.1063/1.3669449 Molecular structure-dynamics relationships in glassy poly(isophthalamide)s as revealed by wide angle x-ray scattering, dielectric loss spectroscopy, and molecular modelling Nuclear magnetic resonance investigations into long range chain fluctuations in molten poly(ethylene-oxide) Dynamics of poly(oxyethylene) melts: Comparison of 13C nuclear magnetic resonance spin-lattice relaxation and dielectric relaxation as determined from simulations and experimentsThe complex dynamics in supramolecular structures of poly͑p-phenylenes͒ with short ethylene oxide ͑EO͒ side chains ͑known as ''hairy rods''͒ have been studied by combining temperature and pressure dependent dielectric spectroscopy ͑DS͒ with different nuclear magnetic resonance ͑NMR͒ techniques. The system forms a periodic lattice of layers of the main chains separated by layers of the amorphous EO chains. Since the dipole moment is located on the EO side chain, DS is probing mainly the side-chain motions and only indirectly the backbone dynamics. On the other hand, the different NMR techniques are also sensitive to the backbone mobility and provide the molecular origin of the dynamic processes. Two dielectrically active processes exist, a ''fast'' ␤ ͑which differs from the usual Johari-Goldstein ␤ process found in homopolymers and low molecular weight glass-forming liquids͒ and a ''slow'' ␣ process with the latter carrying most of the intensity. Comparison of the NMR and dielectric results identifies the outer EO units as solely responsible for the dielectric ␤ process whereas both the short EO segments and the unfreezing of the internal backbone dynamics including bending motions contribute to the ␣ process. The unfreezing of the backbone dynamics does not lead to the dissolution of the structure that only happens at even higher temperatures. Hairy rod molecules thus can serve as model systems which provide the means of studying the effect of confinement on the dynamics. In this respect, the effect of confinement is mainly on the temperature dependence of the ␣-process relaxation times.

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