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Available Poly (available + poly)

Distribution by Scientific Domains

Polymers and Materials Science	80%

Selected Abstracts

Evaluation of performance of polyurethanes based on hydroxy alkylated cardanol formaldehyde resins under aging conditions,

ADVANCES IN POLYMER TECHNOLOGY, Issue 2 2004
K. Sathiyalekshmi
Abstract Rigid polyurethanes were synthesized using hydroxy alkylated cardanol formaldehyde and hydroxy alkylated dimerized-cardanol formaldehyde resins and dicyclo hexyl methane diisocyanate. The studies on the aging (hydrolytic stability, absorption of water/toluene, chemical resistance, dimensional stability, and thermal stability) of these polyurethanes reveal appreciable stability. The performance of these polyurethanes was compared with elastoplastic polyurethanes synthesized with the addition of commercially available poly(ethylene glycol). The rigid polyurethanes are distinctly stable than elastoplastic polyurethanes under various aging conditions. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 91,102, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20005 [source]

Fluorescent, molecularly imprinted thin-layer films based on a common polymer,

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007
Piotr Cywinski
Abstract Fluorescent, molecularly imprinted polymer thin films, with cyclic guanosine 3,,5,-monophosphate (cGMP) as a template and 1,2-diphenyl-6-vinyl-1H -pyrazole-[3,4- b]-quinoline as a fluorescent receptor, were prepared according to a method based on commercially available poly (methyl methacrylate). This method of preparation predicts photoinduced crosslinking in the mixture of polymer chains and involved components. The advantages of this method are the relative simplicity of its preparation and the fact that a common polymer can be used. The spin-coated thin-layer films of imprinted and nonimprinted polymers were studied with the use of fluorescence microscopy with a scanning range of 80 × 80 ,m. A strong fluorescence quenching effect was observed when a cGMP-imprinted film was incubated in aqueous solutions of cGMP, but a comparatively small effect was observed for a nonimprinted polymer and when an imprinted film was incubated with cyclic adenosine 3,,5,-monophosphate (cAMP). The separation factor by the imprinted polymer was determined to be 2.55 for cGMP against cAMP. The obtained polymeric sensor appeared to be stable during subsequent measurements after rewashing and readsorption. The homogeneity of the surface of the polymer film, dependent on the method of film preparation, was also studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 229,235, 2007 [source]

Cell-type specific evaluation of biocompatibility of commercially available polyurethanes

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2009
Karla Lehle
Abstract The biocompatibility of different commercially available poly(ether)urethane (PUR), medically used as main component for pump chambers of implantable ventricular assist devices (VAD), was evaluated. We investigated the influence of the PUR manufacturing process in an in vitro cytotoxicity screening assay. Human saphenous vein endothelial cells (HSVEC) and a mouse fibroblast cell line (L929) were cultivated with different PUR specimens. Tissue-cultured polystyrole (TCP) was used as a reference. The cytotoxic effect was evaluated by morphology (phase contrast microscopy), cell viability (mitochondrial acitvity), cell growth kinetics, and proliferation (incorporation of 3H-methyl-thymidine) tests. Fibronectin-coating guaranteed the adhesion of both cell types onto the reference material. Sterilization procedure of test materials did not affect adhesion properties. L929 completely covered the surfaces of Tecothane®, Carbothane®, and Mecora specimens, whereas HSVEC formed an imperfect monolayer onto the PUR. The mitochondrial activity was reduced in all cell types attached to PUR. In addition, proliferation of cells was not observed when using these materials. Commercially available PUR provided an unfavorable support for colonization of patient-derived HSVEC, which demanded a surface modification. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source]

Multistimuli responsive micelles based on well-defined amphiphilic comb poly(ether amine) (acPEA)

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2010
Chunfeng Di
Abstract A series of well-defined amphiphilic comb poly (ether amine)s (acPEAs) were successfully synthesized through nucleophilic addition/ring-opening reaction of commercial available poly(propylene glycol) (PPO) diglycidyl ether and Jeffamine L100, followed by esterification of hydroxyl groups in backbone by alkyl carboxylic acid with different chain length. acPEAs are comprised of hydrophilic short PEO chains and hydrophobic alkyl chains as comb chains, which are grafted on PPO backbone alternately to form well-defined structure. With the very low critical micelle concentration (CMC) of around 3.0 × 10,3 g/L, the obtained acPEAs can self-assemble into stable nanomicelles, whose aggregation is responsive to temperature, pH, and ionic strength with tunable cloud point (CP). The CP of acPEAs' aqueous solution increases with the decrease of the length of graft alkyl chains, the decrease of pH value, and the decrease of ionic strength. A transition behavior in the responsive aggregation of micelles formed by acPEA8 and acPEA10 in aqueous solution, especially at low pH value (<7.0), was observed, which was also revealed by DLS results. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3468,3475, 2010 [source]

Facile Access to an Efficient Solid-Supported Click Catalyst System Based on Poly(ethyleneimine)

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 1 2009
Lies Bonami
Abstract A novel heterogeneous copper(I) catalyst system, which is based on readily available poly(ethyleneimine), has been used as a recyclable catalyst for Cu(I) catalyzed "click" 1,3 dipolar cycloaddition reactions of azides and alkynes in organic media. Branched poly(ethyleneimine) was first methylated and then cross-linked with 1,9-dibromononane. Subsequently, after the immobilization of Cu(I)Br, this system was applied for heterogeneous copper catalyzed click chemistry of a few model reagents and polymeric compounds. [source]