Novel side chain polypseudorotaxanes with cucurbit[7]uril (CB[7]) threaded onto the side chains are synthesized from a water-soluble polymer and CB[7] in water by simple stirring at room temperature. CB[7] beads could move from the hexyl groups to the benzyl and a part of viologen units in the side chains of polymer when the molar ratio of CB[7] to the monomer reaches from 1 to 2 as shown by ¹H NMR studies, and it is considered that the hydrophobic and charge-dipole interactions of CB[7] are the driving forces. The sizes of the polypseudorotaxanes with different molar ratio of CB[7] to 4VBVHeP in aqueous solution increase with increasing the molar ratio of CB[7] to 4VBVHeP as found by DLS and resonance light scattering, while the typical cyclic voltammograms and UV–vis data indicate that CB[7] are not threaded in the viologen units of P4VBVHeP, and the oxidation reduction characteristic of the polymer is remarkably affected by the addition of CB[7]. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

A novel method for preparing complex beads composed of hydrolyzed polyacrylamide (HPAM) and chitosan, based on the electrostatic attraction between COO⁻ of HPAM and Al³⁺ and between COO⁻ and NH₃⁺ of chitosan, was established. In the two-stage crosslinking process, first Al³⁺ was used as a crosslinking agent for the crosslinking of HPAM molecules, which were used as the skeleton structure of the gel beads. In the second stage, chitosan diffused into the skeleton structure. The gel beads were characterized with scanning electron microscopy, inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. There was a chitosan component in the gel beads, and these gel beads had porous and rough surfaces. The swelling properties of the HPAM–chitosan gel beads were measured in water, in acidic, neutral, and alkaline buffers, and in different saline solutions. The swelling ratio was as high as 3675 g/g in water and 170 g/g in a 0.15 mol/L NaCl solution. The beads showed pH sensitivity in buffers of different pH values and salt sensitivity in different saline solutions. The order of the equilibrium absorbency of the gel beads in different saline solutions was Na⁺ > K⁺ > Mg²⁺ > Ca²⁺ > Al³⁺. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

A novel side-chain polypseudorotaxanes P4VBVBu/CB[7] was synthesized from poly-N-n-butyl-N′-(4-vinylbenzyl)-4,4′-bipyridinium bromide chloride (P4VBVBu) and cucurbit [7]uril (CB[7]) in water by simple stirring at room temperature. CB[7] beads are localized on viologen units in side chains of polypseudorotaxanes as shown by ¹H NMR, IR, XRD, and UV–vis studies, and it is considered that the hydrophobic and charge-dipole interactions are the driving forces. TGA data show that thermal stability of the polypseudorotaxanes increases with the adding of CB[7] threaded. DLS data show that P4VBVBu and CB[7] could form polypseudorotaxanes, and the average hydrodynamic radius of the polypseudorotaxanes increases with increasing the concentration of CB[7]. The typical cyclic voltammograms indicate that the oxidation reduction characteristic of P4VBVBu is remarkably affected by the addition of CB[7] because of the formation of polypseudorotaxanes and the shielding effects of CB[7] threaded on the viologen units of polypseudorotaxanes. With the increase of the concentration of KBr or K₂SO₄, the formation of the polypseudorotaxanes was inhibited due to the shielding effects of both Br⁻ or SO to viologen ion and K⁺ to CB[7] by UV–vis. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2135–2142, 2010

Amphiphilic thermo-responsive multiblock polycarbonates consisting of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) were facilely synthesized using triphosgene as coupling agent. The structures and molecular characteristics of the polycarbonates were confirmed by ¹H-NMR, FT-IR and Gel permeation chromatography (GPC). The crystallization behavior and thermal properties of the polycarbonates were studied using X-ray diffraction (XRD), Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Surface tension measurements confirmed that the critical micelles concentration of polymeric micelles were concentration ranges, which varied from about 2–70 mg/L to 5–40 mg/L with increasing PEO/PPO composition ratio from 0.8 to 1. Dynamic light scattering (DLS) experiments showed bimodal size distributions, the aggregates size increased with increasing the concentration of the polycarbonates aqueous solutions. The size of the aggregates acquired from TEM was smaller than that from DLS owing to the fact that TEM gave size of the aggregates in dry state rather than the hydrodynamic diameter. The degradation process revealed that the degradation rate of the aggregates could be accelerated with an increase in temperature. Moreover, the more the polycarbonate was hydrophilic, the faster was its degradation. Rheological measurements suggested that these multiblock polycarbonates were thermo-responsive and by regulating the PEO/PPO composition ratio they could form a gel at 37°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The novel copolymers of acrylamide (AM) with complex pseudorotaxane monomer (BAMACB) of butyl ammonium methacrylate (BAMA) and cucurbit[6]uril (CB[6]) were prepared via free-radical polymerization in aqueous solution. The copolymers containing pseudorotaxane (PAM/BAMACB) were characterized by ¹H-NMR, FTIR, elemental analysis, TGA, and DSC. The glass transition temperature (T_g) of the copolymer PAM/BAMACB are higher than that of the copolymer of acrylamide and butyl ammonium methacrylate (PAM/BAMA) because of the enhanced rigidity and the bulky steric hindrance of BAMACB side chain in PAM/BAMACB. The molecular weights of copolymer PAM/BAMACB were obtained via static light scattering. The hydrodynamic radii of coils or aggregates were investigated by dynamic light scattering. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5999–6008, 2008