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The nitroxide-mediated polymerisation (NMP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA) with a small amount of styrene (S) as a comonomer was performed in water at 90 °C using 2,2'-azobis [2-(2-imidazolin-2-yl)propane]dihydrochloride (VA-044) as initiator and N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide (SG1) as nitroxide. The reaction was well-controlled and exhibited...
We report the preparation of cross-linked poly(l-lysine) (PLL), polyethylene glycol-block-poly(l-lysine) (PEG-b-PLL), and poly(l-lysine)-block-polysarcosine (PLL-b-PSar) gel particles with size ranged between 100 and 250 nm by emulsion and their evaluation as carriers/encapsulants for protein encapsulation/delivery. Their size and solution property were depended upon polymer molecular weight, composition,...
The bulk physical aging behavior of cross-linked polystyrene (PS) is directly compared to that of its linear precursor polystyrene-co-vinylbenzocyclobutene (PS-VBCB) with 8.5 or 12.5 mol% VBCB content. The VBCB units incorporated into a linear PS precursor cross-link with one another upon annealing at 250 °C. Physical aging rates of bulk PS-VBCB films before and after cross-linking are characterized...
In this study, the lattice fluid (LF) and non-equilibrium lattice fluid (NELF) theories combined with the modified Fick's law and free volume theory were employed to develop mass transfer models for the prediction of gas sorption and permeation in glassy and rubbery membranes in a wide range of temperature and pressure. The finite element method using COMSOL multi-physics software was used to solve...
This contribution proposes the present day picture of dendrimers as a transition from a non-compact sphere to a dense space filling hyperbolic topology, which contradicts the existing perception of a dendrimer with a dense core and open periphery. The unusual maximum in the generation dependent intrinsic viscosity is analyzed within the framework of the optimized Rouse-Zimm theory with excluded volume...
The self-assembly of the amphiphilic lipid molecules in aqueous solution is investigated via dissipative particle dynamic simulation. Lipid bilayer and perforated bilayer membranes, together with the micelles and vesicles, which couple the spatial inhomogeneity and orientation ordering, are observed in equilibrium states and dynamics processes. For the equilibrium states, the phase diagrams are arranged...
The film quality is the core to produce long-life and efficient organic light emitting devices by ink-jetting printing technology which is deeply related to the ink droplet coalescence process, especially the coalescence bead morphology and thickness. However, the fluid flow from impacted drop to the previously deposited drops (drop to bead flow) usually leads to an asymmetry and heterogeneity of...
A PEG-based copolymer with a high PEG ratio was synthesized and the sol-gel transition temperature (Tgel) around the physiological temperature (25 °C–37 °C) was achieved. Specifically, we synthesized a triblock PEG copolymer of poly (d,l-lactide-co-glycolide)-b-poly (ethylene glycol)-b-poly (d,l-lactide-co-glycolide) (PLGA-PEG-PLGA) with different molecular weights and a high PEG/PLGA ratio of 0.80...
Coarse-grained molecular dynamics simulations of the formation of 3- and 6-functional polymer networks explicitly shows gelation via large dendritic clusters. The heterogeneous network structures are studied in detail; clusters have pendant structures and occupy significant volume fraction. Cluster fractal dimension and the Fisher exponent for cluster size are consistent with percolation theory and...
The nonlinear relaxation behavior of olefin multiblock copolymers subjected to step shear strains has been investigated. Compared to homogeneous polymer, a two-step relaxation behavior was identified in olefin multiblock copolymers, with the faster one for the chain relaxation and the slower one for the domain relaxation. It is found that the domain relaxation has stronger strain dependence than the...
One acetylenic monomer (APCB) containing carborane with extremely thermal and thermo-oxidative stability was synthesized and used as the thermal copolymerization component with acetylene-terminated imide monomer (m-EFDA) to improve the thermal and thermo-oxidative stability of the polyimide materials. The curing behavior of the blends of imide monomer and APCB was investigated by FT-IR and DSC. Rheometer...
Strain-induced crystallization (SIC) in unfilled and carbon black or silica filled Natural Rubber (NR) with and without silane is investigated. The method introduced in this paper is based on measurements of the surface temperature during tensile test, whereby SIC is quantified by dividing the produced heat into different contributions, namely the dissipative heat, entropy-related reversible heat...
A dianhydride monomer 2, 5-bis(3, 4-dicarboxyphenoxy)-4′-phenylethynyl biphenyl (PEPHQDA) containing a chain extendable phenylethynyl pendant group has been successfully synthesized via successive nucleophilic substitution, Sonogashira cross-coupling, hydrolysis and dehydration reactions. A flexible microporous polyimide network has been prepared based on the use of triamine (TAPOB), affording hyperbranched...
An inherent structural nanoheterogeneity in statistical hydrogels leads to a peculiarity in macroscopic tensile properties. Some types of statistical hydrogels with considerable degrees of non-uniform distribution of cross-link, which are formed via free radical copolymerization of mono- and bi-functional monomers, are unusually extensible: The elongation at break before and after equilibrium swelling...
In this study, we report three new metal-free molecularly engineered pendant chromophore bearing polymers, coded POTZP1, POTZP2 and POTZP3. Push-pull methacrylate polymer-sensitizers consisting of phenothiazine as donor and oxindole as π-conjugating linker and tetrazole as anchoring/acceptor, were designed and synthesized for dye-sensitized solar cells (DSSCs). Optical, electrochemical and photovoltaic...
The interdiffusion of the C8, the C9 and the C10 aldehyde molecules into a glassy uncrosslinked polymer film composed of four components is studied by using coarse-grained (CG) molecular dynamics simulations. Effects of the aldehyde molecule size, water and temperature on the interdiffusion processes are probed. It is found that (i) the interdiffusion generally follows the smaller-the faster rule...
Due to their chemical and morphological versatility, polyurethanes may be susceptible to fabrication conditions (curing procedure, moisture). Industry reports ‘maturation’ phenomena, i.e. unstable mechanical properties of PU elastomers and PU based adhesive joints right after fabrication. This paper elucidates the impact of fabrication conditions and possible causes of maturation. Chemical and physical...
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