An isotactic polypropene (i-PP) prepared with a metallocene catalyst system and two random copolymers of propene and ethene with 2.8 and 5.7 wt % ethene, respectively (PP-co-E-2.8, PP-co-E-5.7), were isothermally crystallized during simultaneous small- and wide-angle X-ray scattering (SAXS, WAXS) in synchrotron measurements. Identical measurements were carried out after adding 0.3 wt % N,N‘-dicyclohexyl-2,6-naphthalene dicarboxamide, a β nucleating agent (β-NA). All samples form the γ-modification to a certain extent. WAXS data show that the α-modification is predominant in i-PP, PP-co-E-2.8, and PP-co-E-5.7 isothermally crystallized without β-NA at temperatures below 125 °C. Adding β-NA leads to significant amounts of the β-modification at all crystallization temperatures in all three samples. Thus, the three modifications can be tailored by the crystallization regime of the nucleated samples. The simultaneous occurrence of the three modifications has also implications on the SAXS data. The formation of the γ-modification in addition to the α-modification does not lead to a one-dimensional correlation function K(z) with two distinct long periods or lamella thicknesses. In contrast, the formation of the β-modification results in a long period which can be distinguished from that of the other modifications after generating K(z).

Poly­(ethylene oxide) (PEO) is a polymer of great interest due to its prevalence in biomedical, pharmaceutical, and ion conductive systems. In this study, the crystallization behaviors of a PEO with 22 monomer units (PEO22) and a PEO having the same degree of polymerization but with an additional 1,4-disubstituted 1,2,3-triazole ring in central position of the chain (PEO11-TR-PEO11) are investigated. PEO11-TR-PEO11 shows one type of lamella crystal after cooling to T = 0 °C, but structural changes during heating below their final melting are detected by WAXS, DSC, POM, and solid-state NMR spectroscopy. The lamella thickness increases, but simultaneously the helix–helix distance decreases and an additional Bragg reflection appears at 2θ = 22.1°. A model is proposed which explains these structural changes by incorporation of the TR ring into the crystals which are additionally stabilized by attractive C–H···π interactions of the TR rings. Additionally, two different types of extended chain lamella crystals are found in PEO22 by SAXS which are discussed in the context of fractionation caused by the molar mass distribution obtained from MALDI-ToF data.

A series of amphiphilic diblock copolymers and triphilic triblock copolymer analogues of the architectures BA, CAB, and CBA have been synthesized and characterized with respect to their aggregation behavior in water. The A, B, and C components of the block copolymers are formed by hydrophilic poly(glycerol monomethacrylate) (PGMA), lipophilic poly(propylene oxide) (PPO), and a fluorophilic perfluoroalkyl segment, respectively. Their critical micelle concentrations in water are determined from surface tension measurements. The aggregation behavior of the copolymers, as investigated by DLS, SANS, AFM, and TEM, is found to be governed by the strong immiscibility between the lipophilic PPO blocks and the fluorophilic perfluorocarbon segments as well as the blocks sequence. It is found that the BA and CBA copolymers form clear micellar solutions in contrast to the CAB copolymer solutions which exhibit phase-separation above the LCST of the PPO block.

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Amphiphilic di‐ and triblock copolymers containing poly(ethylene oxide) (PEO) as the hydrophilic block and poly(perfluorohexylethyl methacrylate) (PFMA) as the hydrophobic block were synthesized by atom‐transfer radical polymerization using hydroxy‐terminated PEO as the macroinitiator. The copolymers were characterized by size exclusion chromatography and 1H NMR spectroscopy. Self‐association in aqueous solution has been investigated using surface tension measurements, dynamic light scattering (DLS), and transmission electron microscopy (TEM). From surface tension measurements in water, a characteristic concentration (c*) can be detected, which is interpreted as the critical micelle concentration (cmc). The cmc decreases with an increase in fluoro content in the triblock copolymer up to 11 wt.‐% PFMA (solubility limit). DLS studies have been carried out for different samples above the cmc, showing small aggregates (micelles) and single chains for diblock copolymer solutions. In the case of triblock copolymers large clusters were the dominant aggregates in addition to the micelles and single chains. The effect of temperature and concentration on the micelle and cluster formation has been investigated by DLS. Micelle size was found to be resistant to any change by temperature, however, a slight but significant increase in apparent hydrodynamic radius was observed with an increase in concentration, while both temperature and concentration affected the formation of large clusters, especially in concentrated solutions. TEM has been carried out to visualize the morphology of the aggregates after transferring the solution to carbon film. The initial concentration for the preparation of TEM samples was found to have a strong influence on the morphology of the aggregates. By adding colloidal gold particles to the solutions, the typical covering by the polymer was observed by TEM.Decay‐rate distributions for PEO10F5 (4.0 g · L−1); obtained from the time correlation functions.magnified imageDecay‐rate distributions for PEO10F5 (4.0 g · L−1); obtained from the time correlation functions.

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The tremendous influence of hydrophilic block length tuning on the aggregation behavior of novel water-soluble triphilic (i.e., hydrophilic, lipophilic, and fluorophilic) R,ω-perfluoroalkyl end-capped symmetric ABA triblock copolymers is demonstrated. The hydrophilic A and lipophilic B blocks are comprised of poly(glycerol monomethacrylate) (PGMA) and poly(propylene oxide) (PPO), respectively. The fluorophilic component consists of two "clicked" perfluoroalkyl segments (C 9 F 19 ) at the ends of the block copolymers. Two of the different block copolymers synthesized, namely F 9 -PGMA 24 -PPO 27 -PGMA 24 -F 9 (PB1) and F 9 -PGMA 42 -PPO 27 -PGMA 42 -F 9 (PB2), differ only in the degree of polymerization of the hydrophilic PGMA blocks. Their critical micelle concentrations in water are determined from surface tension measurements. The aggregation behavior in aqueous medium studied by 19 F NMR spectroscopy reveals that the fluorocarbon component forms part of the micelle corona of PB1, while in PB2 it aggregates to form part of the core. Furthermore, the aggregation behavior studied in aqueous medium by temperaturedependent 1 H NMR spectroscopy and DLS measurements showed that PB1 forms only spherical micelles with hydrodynamic radius, R h , of ∼18 nm in solution at all temperatures while PB2 forms mainly aggregate of micelles with R h of 40 nm at 25 °C. The aggregates disintegrate into compact single "flowerlike" micelles with R h of ∼17 nm at high temperatures. AFM and TEM investigations of the structures formed on solid supports after solvent evaporation also confirm the aggregation behavior of the two block copolymers. The marked difference in the aggregation behavior is a result of the inability of the shorter PGMA blocks of PB1 to loop during micellization and is explained based on random coil statistics.

Di- and triblock copolymers of tert-butyl methacrylate (tBMA) and 2-(N-methylperfluorobutanesulfonamido)ethyl methacrylate (FMA) were synthesized by sequential anionic polymerization. These polymers were characterized by size-exclusion chromatography and 1H and 19F NMR spectroscopy. The microphase separation of bulk samples was studied by atomic force microscopy and small-angle X-ray scattering. Thermal annealing of the block copolymers at 200 °C yielded inter- and intramolecular anhydrides due to the splitting of the ester having tert-butyl groups connected with isobutene formation. This conversion was followed by time-resolved Fourier transform infrared (FT-IR) spectroscopy. The anhydrides can be transformed into the sodium salt of methacrylic acid units in 1 N NaOH under reflux. The thermal ester splitting of the tBMA block at 200 °C did not influence the FMA block. The obtained block copolymers were soluble in water when the FMA content was less than 10 mol %. The behavior of these solutions was studied by various experimental methods. The critical micelle concentration was obtained by surface tension measurements. The micelle dimensions were determined by dynamic light scattering. The size and inner structure of the micelles were investigated by small-angle X-ray scattering and could also be observed by transmission electron microscopy after transfer of the diluted solutions onto carbon films. Typical polyelectrolyte effects were observed by viscosity measurements for PtBMA only. For block copolymers the aggregation behavior is dominating even at very low concentrations.