The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Highly oriented β-PVDF thin layer was produced by shearing the supercooled PVDF melt at 160 oC with a knife blade. The oriented β-PVDF crystals were found to be effective inducing the transcrystallization of the non-sheared PVDF melt at 160 oC and leading to the formation of a transcrystalline α-PVDF layer. Annealing of the transcrystalline α-PVDF, the well-known α-to-γ' phase transition takes place...
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,...
Advanced epoxy resins containing naphthalene and flame retardant moiety [tetrabromobisphenol-A (TBBA) or cyclicphosphineoxidediol] in the backbone were synthesized. T g s of epoxy resins containing naphthalene structure are higher than that of the diglycidyl ether of bisphenol-A (DGEBA), and a T g of 237 o C was obtained when the tetrafunctional naphthalene-containing epoxy...
Water insoluble poly(ε-caprolactone) (PCL) was micronized into narrowly distributed stable nanoparticles. The biodegradation of such PCL nanoparticles in the presence of the enzyme, Lipase PS, was monitored by using laser light scattering because the scattering intensity is directly related to the particle concentration. The PCL and enzyme concentration dependence of the biodegradation rate supports...
The relations among the morphological parameters of binary polymer blends with the morphology of well-dispersed particles are quantitatively studied to correct the error from the simple cubic (sc) lattice assumption made in previous works. A new morphological parameter, the particle spatial distribution parameter ξ, is defined. A new equation for correlating the spatial distribution with other morphological...
Optical thin films of three rod-like polymers, a rigid-rod polymer poly(p-phenylene benzobisthiazole) (PBZT), a diadamantane-substituted PBZT (DMT-PBZT) and a bicyclo[2.2.2]octane-substituted PBZT (BCO-PBZT), at different thicknesses were prepared with the solid-state coagulation process. In contrast to PBZT, DMT-PBZT and BCO-PBZT do not have a π-conjugated backbone because of their aliphatic DMT...
The relationships among morphological parameters of binary polymer blends have been studied. A new equation for correlating morphological parameters: particle size (d), particle size distribution (σ), particle volume fraction (φ), and matrix ligament thickness (T(d, σ, φ)) is derived. The equation is generally applicable to the binary polymer blends with the log-normal distribution of particle size...
The sol—gel process was used to prepare a class of composites in which a high-temperature polymer, poly(phenylene terephthalamide), was reinforced with varying amounts of in-situ generated titania. The polymer was synthesized by reacting a mixture of p- and m-phenylene diamines with terephthaloyl chloride in dimethylacetamide, using stoichiometry yielding chains with carbonyl chloride end groups....
A novel coagulation processing scheme has been developed to fabricate optical quality polymer thin films for non-linear optical applications. In this process, termed solid state coagulation, an optically isotropic polymer solution is rapidly frozen into a solid mixture to preserve the molecular dispersion of the polymer in the solvent. It is then coagulated at a cryogenic temperature in a proper...
A number of homo- and copolymer benzobisazole rigid-rod polymers have been synthesized, containing labile methyl pendants and benzocyclobutene groups for thermally induced crosslinking studies. Polycondensations of tetraamino, diaminodihydroxy and diaminodithio monomers with methyl, dimethyl and benzocyclobutene terephthalic acid derivatives in polyphosphoric acid (PPA) provided high molecular weight...
The morphology and mechanical behaviour of high protein content engineering soy plastics are investigated. These engineering soy plastics can possess significantly higher Young's moduli (4.4 GPa) than those of petrochemical engineering plastics, if the moisture content in the soy plastics is kept low (<5% by weight). The low moisture soy plastic is found to be tougher than diglycidyl ether of...
A simple alkyl lithium initiator (sBuLi) complexed with LiCl (10 molar equiv.) has been used to initiate the anionic polymerization of various methacrylic monomers, i.e. methyl methacrylate (MMA), tert-butyl methacrylate (tBuMA), glycidyl methacrylate (GMA), and dimethyl amino ethyl methacrylate (DMAEMA) in tetrahydrofuran at -78°C. Only the homopolymerization of tBuMA proceeds in a living manner,...
Large voids of about 100 μm are often found in rigid-rod polymer thin films coagulated from isotropic solutions. To understand the mechanism of this void formation so as to improve the optical quality of coagulated rigid-rod polymer thin films, surface and internal structures of various coagulated poly(p-phenylene benzobisthiazole) solutions were investigated on freeze-dried films by high resolution...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.