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Segmented polyurethanes (SPUs) have been designed with controlled hard to soft segment ratios. The confinement effect of the SPU blocks is induced by phase separation of the SPU segments and has been harnessed to selectively control crystallization. Hard segment (HS) concentrations greater than 50wt.% allowed for the study of morphological changes and mechanical properties associated with confinement...
The use of diblock copolymers as chemical templates for the self-assembly of patterned and periodic materials has been the focus of extensive research in recent years. In this current work we show how a “one-pot” solution synthesis, which is based solely on the differences in the chemical reactivity of the two blocks towards metallic moiety, can be extended to create 1-, 2- and 3-dimensional ordered...
Multi-walled carbon nanotube (MWCNT)/polyimide composite films were fabricated through electrophoretic deposition (EPD) of MWCNT-polyamic acid colloidal suspension which was derived from carboxylated-MWCNTs and poly(pyromellitic dianhydride-co-4,4′-oxydianiline) (PMDA-ODA). Under electric field, both negatively charged MWCNTs and PMDA-ODA colloid particles migrate onto a positively charged anode simultaneously,...
The phase behavior of the blends of poly(ethylene terephthalate) (PET) and poly(Resorcinol Phthalate-block-Carbonate) (RPC) and the blends of PET and poly(Bisphenol-A Carbonate) (PC) was investigated by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). Blends of high molecular weight PET and RPC copolymer with 20 mol% resorcinol...
A facile template-free approach to fabricate poly(3-hexylthiophene) (P3HT) into highly aligned microwire film on a large scale via the evaporation of P3HT/Anisole whisker solution has been developed. The microwires in the film typically have the height of 0.8–1.4μm, width of 2–4μm and length of 50–1000μm. X-ray Diffraction and Selected-Area Electron Diffraction results suggest that each microwire...
Here, we studied the mechanical properties of polyacrylic acid-co-polyacrylamide (pAAc/pAAm) and polyacrylate-co-polyacrylamide (pNaAc/pAAm)-based hydrogels as a function of composition and total polymer content. While both polyacrylate and polyacrylic acid are weakly-charged polyelectrolytes with carboxylate side groups, they exhibit different behavior as copolymers with polyacrylamide. In swelling...
We report the first use of photo-initiated miniemulsion polymerization for the synthesis of well defined poly(methyl methacrylate) (PMMA) latexes. Furthermore, the application of photo-initiation is employed to the incorporation of decanethiol-capped gold nanoparticles (AuNPs). The procedure provides a low temperature polymerization for an oil-in-water miniemulsion with temperatures not exceeding...
Honeycomb-patterned films can be facilely prepared by the breath figure method. However, it is still ambiguous how the polymer structure affects the morphologies of the films. In this work, poly(styrene-co-2-(2-,3-,4-,6-tetra-O-acetyl-β-d-glucosyloxy) ethyl methacrylate) (PS-co-AcGEMA) with well-defined linear and/or comb-like structures were synthesized by atom transfer radical polymerization (ATRP)...
Cationic nanogels of Pegylated poly(N,N′-Dimethylaminoethyl methacrylate) (PEG-PDAEMA) have been synthesized in aqueous solution by a one-step surfactant-free reversible addition-fragmentation transfer (RAFT) process. A Pegylated amphiphilic macroRAFT agent (mPEG 550 -TTC) with a hydrophobic dodecyl chain was utilized to stabilize the micelles and control the polymerization and crosslinking...
Optically active, polycarbodiimides 3(a, b & c) with pyridine pendant groups were synthesized using [(R) – 2,2′- binaphthoxy] (di-isopropoxy) titanium(IV) catalyst. The polymers were characterized by 1 H and 13 C NMR, and IR. Thermal stability of these polymers (up to 162 °C by TGA), allows thermally demanding chemical transformations on their side chains without decomposition...
We investigated slip and unstable flow phenomena of polystyrene melts in capillaries from the view of the effects of temperature and molecular weight by using three polystyrene samples with different molecular weights (M w = 192,000, M w = 258,000, and M w = 321,000). The slip velocities are estimated by the Mooney method and the modified Mooney method. We found that the...
The effects of crystallinity, water absorption, hydrolytic degradation, and tacticity on the solid structure and chain mobility of poly(lactide)s were investigated by solid-state 13 C NMR spectroscopy. The following results were obtained from the line shapes of the carbonyl and methine carbons in 13 C NMR spectra and their spin-lattice relaxation behavior. The crystallized poly(l-lactide)...
Langmuir–Blodgett (LB) films of three novel azobenzene-substituted diacetylene monomers (DA1, DA2 and DA3) were fabricated and their optical and chiroptical properties were investigated in detail by ultraviolet–visible (UV–vis) spectra and circular dichroism (CD) spectra. Achiral DA1 molecules could form chiral LB films through overcrowded packing of the azobenzene moiety, while achiral DA2 and DA3...
Exfoliated layered-silicate in the polystyrene (PS) block copolymer with different molecular weights was employed as a model material to investigate the PS nanocomposite microcellular foams expanded by supercritical carbon dioxide. Using a well-controlled foaming procedure, we investigated the influence of molecular weight of PS, dispersion and loading of layered-silicate and pressure drop rate of...
Generating patterns of cells on surfaces is of great significance not only for fundamental studies in biomedical science but also for the creation of functional customized tissue or organs in regenerative medicine. In this paper, arbitrary, complex stem cell patterns were created using piezoelectric inkjet printing of biocompatible polymers. After a systematic study with different inkjet process variables,...
New functional terpolymers of citraconic anhydride (CA), styrene (S) and vinylphosphonic acid (VPA) were synthesized at different compositions by complex-radical ternary polymerization. Studied ternary acceptor-donor-acceptor system was described as a binary copolymerization of two monomer complexes of CA…S (1) and VPA…S (2). The monomer reactivity ratios of these complexes were determined by ...
Copper-catalyzed alkyne-azide “click chemistry” is applied in the preparation of tadpole-shaped (“monochelic”) POSS-end functional hybrid polymers by combining with ATRP and RAFT polymerization. Alkyne-functionalized ATRP initiator and RAFT agent were respectively synthesized and applied in the preparation of alkyne-terminal poly(methyl methacrylate) and polystyrene. The tadpole-shaped POSS-containing...
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