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Flow-mode static and dynamic laser light scattering (SLS/DLS) studies of polymers, including polystyrene, polyethylene, polypropylene and poly(dimethylsiloxane) (PDMS), in 1,2,4-trichlorobenzene (TCB) at 150 °C were performed on a high temperature gel permeation chromatography (GPC) coupled with a SLS/DLS detector. Both absolute molecular weight (M) and molecular sizes (radius of gyration, R g...
Approximately 30 years after their preparation, the nanoscale morphology of a series of ‘model’ segmented polyurethane elastomers has been further elucidated using the technique of tapping mode AFM. The materials investigated are based on 1,4-butanediol extended piperazine based hard segments and employ poly(tetramethylene oxide) soft segments. The chemistry of these polyurethanes was specifically...
A family of segmented low MW poly(ethylene glycol)-poly(epsilon-caprolactone) (PEG-PCL) oligomers was synthesized by reacting PCL-based macrodiisocyanates and diblocks comprising MPEG and PCL short segments. The oligomers have the following general structure: MPEG350-(CL) n -HDI-PCL530-HDI-(CL) n -MPEG350. The composition of the oligomers and their molecular weight was determined by...
In an effort to prepare a poly(vinylidene fluoride)–hexafluoropropene (PVdF–HFP) based polymer gel film electrolyte with higher mechanical strength and little volatility, a two component urethane system employing blocked multiisocyanate as a potential thermal crosslinking agent, and low molar mass poly(ethylene glycol) (PEG) as a hydroxy-functional coreactant was blended with the PVdF–HFP gel system,...
A novel fluorinated bis(ether amine) monomer, 2,3-bis(4-amino-2-trifluoromethylphenoxy)naphthalene, was prepared through the nucleophilic aromatic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 2,3-dihydroxynaphthalene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. A series of new fluorine-containing polyimides having inherent viscosities...
Near, mid and far infrared spectra have been recorded for methyl methacrylate–methacrylic acid copolymers and their sodium salts. Methyl methacrylate–methacrylic acid copolymers, with various methacrylic acid contents were prepared by free radical polymerization. The sodium salts of (methyl methacrylate–methacrylic acid) copolymers were prepared by reaction of methacrylic acid units with sodium hydroxide...
We synthesized the polyelectrolyte complex hydrogel consisting of chitosan, κ-carrageenan, and carboxymethyl cellulose sodium salt (NaCMC) and investigated the swelling properties of the gel varying with carrageenan/NaCMC compositions. In a lower composition of carrageenan, heterogeneous gels were obtained indicating strong electrostatic interactions among these polyelectrolytes. Oppositely, in a...
The stepwise insertion reaction of styrene (St) and p-tert-butoxystyrene (BOSt) into poly(alkoxyamine) macroinitiator was carried out to provide well-defined poly(St)-b-poly(BOSt) multiblock copolymers. Structural confirmation of the multiblock copolymers was accomplished by NMR and IR measurements. The model reaction also supported that the monomer insertion into the macroinitiator proceeded in accordance...
A series of poly(butylene succinate) ionomers (PBSi) containing 5-sodium sulfoisophthalate units were prepared by bulk polymerization of succinic acid and 1,4-butanediol in the presence of dimethyl 5-sulfoisophthalate sodium salt (DMSI) up to 5mol% of diacid monomer. Conspicuous variation of the storage modulus for PBSi was observed, depending on the content of DMSI. The increasing rate of cluster...
An extensive work was performed to analyze how and why electrical properties of carbon black filled rubber compounds change during thermal aging. Several compounds were prepared using different polymer matrices and a broad range of carbon black types. Electrical resistivity of cured and uncured samples was measured, under different conditions, during thermal aging at constant temperature. Other experimental...
Rheo-optical Fourier-transform infrared (FTIR) spectroscopy is based on the simultaneous acquisition of stress–strain data and FTIR spectra on-line to the mechanical treatment of polymers and is frequently applied for the characterization of transient structural changes during deformation and stress-relaxation. In the present communication, this technique has been employed in order to investigate...
In this study, the new polymer–silica hybrid materials were prepared based on the organo-soluble polyimides of 4,4′-hexafluoroisopropylidenediphthalic anhydride (6FDA) and four diamines. 3-Aminopropyl trimethoxysilane (APrTEOS) and γ-glycidyloxypropyltrimethoxysilanes (GOTMS) were used to increase the intrachain chemical bonding and interchain hydrogen bonding between the polyimide and silica moieties,...
The synthesis and characterisation of a new type of high melting and fast crystallising amide units that can be used for copolymerisation have been studied. These bisester tetra-amide or TxTxT-dimethyl segments (T is a terephthalic unit and x=(CH 2 ) n (n=2–8)) can be synthesised in a two-step reaction. These segments are based on two-and-a-half repeating units of nylon-x,T. The structure...
The Pd-PCy 3 (Cy=cyclohexyl) system effectively catalyzed hydrosilylation polymerization of dihydrosilanes with p- or m-diethynylbenzene to give silylene-divinylene polymers with Ph, Me, and/or vinyl substituents at the silicon atoms. The resulting polymers showed characteristic absorption and fluorescence spectra in ultraviolet to visible region. p-Phenylene polymers displayed λ max ...
Combined static and dynamic light scattering was used to characterise a variety of sodium poly(acrylate) samples in dilute aqueous solutions with added NaCl. An increase of the NaCl content resulted in a decrease of the solvent quality. On the basis of these findings, two solvent conditions were selected for a detailed investigation of the coil size as a function of the molar mass M w : aqueous...
Telechelic poly(2,6-dimethyl-1,4-phenylene ether) (PPE) segments are interesting starting materials, for example for copolymerisation. A good method to make partly bifunctional PPE-2OH is by redistribution or depolymerisation of high molecular weight commercial PPE with tetramethyl bisphenol A. The product has a bimodal molecular weight distribution because only ∼70–80% of high molecular weight starting...
X-ray photoelectron spectroscopy (XPS) applied to the study of fluorinated polymer surfaces presents several problems related both to peak assignment and to degradation. In this work, we analyse extensively the question of XPS peak assignments in this kind of surfaces. We conclude that in this kind of surfaces using binding energy differences between fluorine and carbon is better than using absolute...
The coil-to-globule and globule-to-coil transition of poly(N-isopropylacrylamide) in aqueous solution had been studied by heating and cooling the sample solution with conventional viscosity measurement. A single chain collapsed globule solution was prepared firstly by adding sodium n-dodecyl sulfate (SDS) into the polymer solution at room temperature, as the chain collapsed to compact globule at higher...
Anionic and radical polymerizations of N-methyl-N-allyl-2-(ethoxycarbonyl)allylamine (1) were undertaken to search the possibility for controlling the structure of the polymers therefrom. Completely cyclized polymers with a five-membered ring as a repeat cyclic unit were obtained by radical polymerizations. Anionic polymerizations by lithium compounds such as tert-butyl lithium and lithium 4-benzylpiperidide...
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