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Novel hydrogel polymers were prepared by the crosslinking reaction between polyethylene glycol monophosphate ester (PEGP) and isosorbide diglycidyl ether (IDE). The crosslinking reaction involved no solvents and occurred at room temperature without catalyst. Curing kinetics was studied by differential scanning calorimetry (DSC) and chemorheometry. Because the three-dimensional network structure of...
Controlling crystal phase transition from modification II to I in isotactic Poly-1-butene (iPB-1) using CO 2 is presented in this article. The intrinsic kinetics of CO 2 -induced phase transition from modification II to I in iPB-1 at 40 °C and different CO 2 pressures were detected using in situ high-pressure Fourier transform infrared spectroscopy (FTIR) and correlated by...
Polystyrene (PS) foams with isotropy cell morphology and oriented cell morphology were prepared to investigate the relationship between the cell morphologies and the mechanical properties (tensile and impact properties). For the isotropy cell morphologies, the tensile strength, tensile modulus and impact strength of PS foams all increase with the increase of relative density. When the relative density...
With varying the molecular weight, copolymer chemical structure and concentration, the probe diffusion behavior of single-walled carbon nanotubes (SWCNTs) in N, N-dimethylacetamide (DMAc) solutions of polyacrylonitrile (PAN) was studied by dynamic light scattering (DLS) technique. In combination with the systematic viscosity property investigation for PAN/DMAc system, the probe diffusion results provided...
In this work, we found a new method to obtain isotactic poly-1-butene (iPB-1) with form I′ through direct melt-crystallization using high-pressure CO 2 . The non-isothermal melt-crystallization behaviors of iPB-1 under atmospheric N 2 and 0.5–10MPa CO 2 at cooling rates ranging from 0.25 to 5°C/min were carefully studied using high-pressure differential scanning calorimeter...
In-situ high-pressure FTIR was used to investigate the polymorphous phase transition of isotactic poly-1-butene (iPB-1) with form III upon annealing at temperatures ranging from 75 to 100 °C and CO 2 pressures ranging from 2 to 12 MPa. It was shown that the phase transition of form III changed from form III to II not through form III to I′ with increasing temperature and application of CO...
Vesicles are membrane-enclosed capsules that can store or transport substances. Their structures and the corresponding structural transitions are important to fulfill specific functions. Using dissipative particle dynamics method, we study the complex structure transitions of vesicles that are spontaneously formed by A 6 (B 2 ) 3 type comb-like block copolymers. In the simulations,...
Novel supramolecular system of amphiphilic hyperbranched polymer with hyperbranched poly(β-cyclodextrin) core was designed and synthesized to accomplish a so-called selective encapsulation, where two types of guest molecules can be encapsulated into two types of molecular cavities from β-cyclodextrin (β-CD) and topography structure of hyperbranched polymer, respectively. The double molecular recognition...
The solid-solid crystalline transformation of isotactic polybutene-1 (iPB-1) from tetragonal form II to hexagonal form I could be accelerated by supercritical carbon dioxide (scCO 2 ). In this study, in-situ Fourier transform infrared spectroscopy (FTIR) and two dimensional correlation spectroscopy (2DIR) is used to observe and investigate the crystallization behaviour of iPB in scCO 2...
Dissipative particle dynamics simulation is performed to study the sensitive influence of the molecular architecture and/or segment sequence on the morphology diversity of the multicompartment micelles. The multicompartment micelle morphologies formed by ABC triblock copolymers with various molecular architectures, such as the linear, the pentalinear, the cyclic, the star-like, the tetra-arm, and...
Geometries, ionization potentials (IPs), electron affinities (EAs) and optical properties of two series of π-conjugated oligomers (2,6-(4,4-bis(2-ethylthexyl)-4H-cyclopenta-[def]-phenanthrene)) n CPPn (2,6-(4,4-bis(2-ethylthexyl)-8,9-dihydro-4H-cyclopenta-[def]-phenanthrene)) n HCPPn (n=1–4) were studied theoretically. The ground and the excited state geometries were optimized by B3LYP...
Structural, electronic, and optical properties of a series of π-conjugated chain type oligomers composed of the bipyridyl, ethynyl and thiophenyl fragments are studied by advanced quantum chemical methods. The properties of the P-oligomers (P1–P4, with 1–4 repeating units, respectively) and the corresponding DP-oligomers (DP2–DP4, with 2–4 repeating units, respectively, but without the terminal thiophenyl...
A series of fluorinated diblock copolymers, consisting of styrene (St)–acrylonitrile (AN) copolymer [poly(St-co-AN)] and poly-2-[(perfluorononenyl)oxy]ethyl methacrylate, with various compositions as well as with different molecular weights were synthesized by atom transfer radical polymerization and characterized. Dispersion polymerization of acrylonitrile in supercritical carbon dioxide (scCO ...
Single wall carbon nanotubes (SWNT) act as a compatabilizer for polyacrylonitrile (PAN)/styrene–acrylonitrile (SAN) copolymer blends. Carbonization of PAN/SAN/SWNT blend films results in pore widths in the range of 1–200nm, while carbonized PAN/SAN blend films resulted in pores with typical width of 1–10μm. Electrochemical supercapacitor behavior of the carbonized PAN/SAN/SWNT films was characterized...
Cross-linking polymerization of acrylic acid in supercritical carbon dioxide (scCO 2 ) was studied in a batch reactor at 50°C and 207bar with either triallyl pentaerythritol ether or tetraallyl pentaerythritol ether as the cross-linker and with 2,2′-azobis(2,4-dimethyl-valeronitrile) as the free radical initiator. All polymers were white, dry, fine powders. Scanning electron microscopy showed...
SWNT were dispersed in PMMA in eight different solvents with varying three dimensional solubility parameters. Results show that for achieving good dispersion, the polar component (δ p ) of the solubility parameter is most important, while the other components, namely dispersive and hydrogen bonding (δ d and δ h ), or the total solubility parameter (δ t ) do not appear...
Single wall carbon nanotubes (SWNT), polyvinyl alcohol (PVA), dimethyl sulfoxide (DMSO) and water, homogeneous dispersion has been prepared by stirring and sonication. This dispersion was extruded into fiber via gel spinning. The modulus of the PVA/SWNT (3wt%) composite fiber was 40% higher than that of the control PVA gel spun fiber. Fiber structure and properties have been studied. The PVA orientation...
Crystallization behavior of melt-blended polypropylene (PP)/single wall carbon nanotube (SWNT) composites has been studied using optical microscopy and differential scanning calorimetry. Polypropylene containing 0.8wt% SWNT exhibits faster crystallization rate as compared to pure polypropylene. PP/SWNT fibers have been spun using typical polypropylene melt spinning conditions. The PP crystallite orientation...
The optical properties of poly(phenylenevinylene) (PPV)/TiO 2 nanocomposites, prepared from mixtures of PPV precursor and titanium butoxide ethanol solution in a sol-gel process, are investigated by UV-VIS, FT-IR, PL spectroscopy and TEM. The TEM images showed that the TiO 2 nano-aggregates took the form of a sphere and finally ellipsoid with an alignment, as the content of TiO ...
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