Synthesis and solution properties of poly(vinyl ether)s with long alkyl chain, biphenyl, and cholesteryl pendants

Precise synthesis of amphiphilic diblock copolymers consisting of various ionic liquid-type segments and their influence on physical gelation behavior in water

Appropriately designed amphiphilic diblock vinyl ether (VE) copolymers consisting of an ionic liquid-type segment and a hydrophobic segment were demonstrated to undergo physical gelation in water at extremely low concentrations. The precursor diblock copolymers were synthesized by the living cationic polymerization of 2-chloroethyl VE with a hydrophobic VE through an appropriately designed initiating system such as optimized temperature and catalyst. A relatively high temperature such as 20 °C was important for controlled polymerization of octadecyl VE. Ionic liquid moieties with imidazolium salt structures were subsequently introduced into the side chains of the diblock copolymers via chemical modifications of the 2-chloroethyl groups. The physical gelation behavior of the obtained diblock copolymers was examined in water, with a particular focus on the influence of the hydrophobic VEs, the hydrophilicity of the counteranions and the substituents on the ionic liquid-type segments, and the length of each segment. Based on this systematic investigation, physical gelation at concentrations as low as 0.2 wt% was achieved with diblock copolymers with a suitable balance of these factors.

Amphiphilic diblock copolymers of hydrophobic and imidazolium salt-containing vinyl ethers were synthesized via living cationic polymerization. The influence of hydrophobic and the ionic-liquid moieties on physical gelation in water was examined.

Poly(mono/diethylene glycol n-tetradecyl ether vinyl ether)s with Various Molecular Weights as Phase Change Materials

At present, research on the relationship of comb-like polymer phase change material structures and their heat storage performance is scarce. Therefore, this relationship from both micro and macro perspectives will be studied in this paper. In order to achieve a high phase change enthalpy, ethylene glycol segments were introduced between the vinyl and the alkyl side chains. A series of poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers) (PC₁₄E_nVEs) (n = 1, 2) with various molecular weights were polymerized by living cationic polymerization. The results of PC₁₄E₁VE and PC₁₄E₂VE showed that the minimum number of carbon atoms required for side-chain crystallization were 7.7 and 7.2, which were lower than that reported in the literature. The phase change enthalpy 89 J/g (for poly(mono ethylene glycol n-tetradecyl ether vinyl ethers)) and 86 J/g (for poly(hexadecyl acrylate)) were approximately equal. With the increase of molecular weight, the melting temperature, the melting enthalpy, and the initial thermal decomposition temperature of PC₁₄E₁VE changed from 27.0 to 28.0 °C, from 95 to 89 J/g, and from 264 to 287 °C, respectively. When the number average molar mass of PC₁₄E_nVEs exceeded 20,000, the enthalpy values remained basically unchanged. The introduction of the ethylene glycol chain was conducive to the crystallization of alkyl side chains.

Thermoresponsivity of polymer solution derived from a self-attractive urea unit and a self-repulsive lipophilic ion unit

Proper design of a self-attractive unit and a self-repulsive ion unit on a polymer chain successfully generated thermoresponsivity in non-aqueous solvents.

Thermoresponsive functional polymers based on 2,6-diaminopyridine motif with tunable UCST behaviour in water/alcohol mixtures

Two thermoresponsive polyacrylamides based on the 2,6-diaminopyridine motif were synthesized and their UCST-type reversible thermoresponsive behaviour was studied in water/alcohol mixtures.

Surface segregation of a branched polymer with hydrophilic poly[2-(2-ethoxy)ethoxyethyl vinyl ether] side chains

A branched polymer with hydrophilic side chains was designed and prepared for anti-biofouling surface construction through its preferential segregation.

Triblock and pentablock terpolymers by sequential base-assisted living cationic copolymerization of functionalized vinyl ethers

A series of novel, well-defined triblock and pentablock terpolymers of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiEGVE) were synthesized by sequential base-assisted living cationic polymerization.