En route to intelligent hydrogels: Copolymers of N‐isopropylacrylamide containing adamantyl groups can be cross‐linked noncovalently with cyclodextrin dimers. This results in thermosensitive hydrogels with cloud points that are lower than those of the pure copolymers. Addition of monomeric methylated cyclodextrin results in an increase in the cloud points but has no significant influence on the viscosity of the copolymer solution.

Pseudopolyrotaxane 2 is synthesized from polyviologen (1) and cucurbituril (CB[6]) in water by simple stirring at room temperature. The degree of threading (number of CB[6] beads per repeat unit) can be precisely controlled from 0.1 to 1.0 by controlling the amount of CB[6] added. In 2, CB[6] beads are localized at the middle of the decamethylene units of the polymer through hydrophobic and charge − dipole interactions, to afford a well-defined microstructure in aqueous medium as found by NMR studies. The pseudopolyrotaxane has higher intrinsic viscosity, but a lower shape-dependent Huggins constant, than the parent polymer. This is attributed to a larger hydrodynamic radius and more expanded chain conformation of the pseudopolyrotaxane compared to those of the parent polymer. The decomposition temperature of 2 increases with increasing amount of CB[6] threaded on the polymer.

Eine nichtkovalente Vernetzung Adamantylgruppen tragender Copolymere von N‐Isopropylacrylamid gelingt mit Cyclodextrin‐Dimeren (siehe Bild). Hierdurch kommt es zur Bildung thermosensitiver Hydrogele, deren Trübungspunkte niedriger als die der unvernetzten Copolymere liegen. Bei Zugabe von monomerem methyliertem Cyclodextrin zu Lösungen der reinen Copolymere steigen die Trübungspunkte; dies hat jedoch kaum Einfluss auf die Viskosität der Polymerlösungen.

SummaryA new series of polymerizable methacrylated anthraquinone dyes has been synthesized by nucleophilic aromatic substitution reactions and subsequent methacrylation. Thereby, green 5,8-bis(4-(2-methacryloxyethyl)phenylamino)-1,4-dihydroxyanthraquinone (2), blue 1,4-bis(4-((2-methacryloxyethyl)oxy)phenylamino)anthraquinone (6) and red 1-((2-methacryloxy-1,1-dimethylethyl)amino)anthraquinone (12), as well as 1-((1,3-dimethacryloxy-2-methylpropan-2-yl)amino)anthraquinone (15) were obtained. By mixing of these brilliant dyes in different ratios and concentrations, a broad color spectrum can be generated. After methacrylation, the monomeric dyes can be covalently emplaced into several copolymers. Due to two polymerizable functionalities, they can act as cross-linking agents. Thus, diffusion out of the polymer can be avoided, which increases the physiological compatibility and makes the dyes promising compounds for medical applications, such as iris implants.

We report on the first examples of the free radical polymerization of a fluorinated 2‐vinylcyclopropane 1 and its copolymerization with an alkyl 2‐vinylcyclopropane 2 in aqueous solution via their host‐guest complexation with a random methylated β‐cyclodextrin (RAMEB) using a water‐soluble initiator (VA50). Upon polymerization, the dethreaded cyclodextrin remained in water solution, whereas the water‐insoluble polymer precipitated out and was isolated. The polymers prepared exhibited mesophase behavior over a wide range of temperature. Both Tg and Ti of the copolymers increased linearly with the amount of fluorinated co‐units.Complexation of fluorinated vinylcyclopropane 1 with RAMEB and polymerization in water solution.magnified imageComplexation of fluorinated vinylcyclopropane 1 with RAMEB and polymerization in water solution.