Polyester Film (polyester + film)

Distribution by Scientific Domains

Selected Abstracts

A simple method for orienting silk and other flexible fibres in transmission electron microscopy specimens

J. E. Trancik
When microstructures are characterized by transmission electron microscopy (TEM), the interpretation of results is facilitated if the material can be sectioned in defined orientations. In the case of fibres, it is especially useful if transverse and longitudinal sections can be obtained reliably. Here we describe a procedure for orienting spider silk and other flexible fibres for TEM investigation. Prior to embedding in epoxy resin, the silk is wound around a notched support made from polyester film. No glue is required. After the silk and its supporting film have been embedded and the resin has been cured the film can be peeled away to reveal nearly perfectly orientated silk threads. Both transverse and longitudinal sections can then be cut with a microtome. The method can be extended to obtain sections at any intermediate orientation. [source]

Synthesis of crosslinkable fluorinated polyesters for optical waveguide devices

Xu Fei
Abstract A series of novel crosslinkable, highly fluorinated polyesters were synthesized by copolycondensation reactions of terephthaloyl chloride with 4, 4,-(hexafluoroisopropy-lidene)-diphenol and 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-octane-1,8-diol, followed by reaction with 2-hydroxyethyl methacrylate. The resulting polyesters with the molecular weights (Mn: 12,100,20,000 g mol,1) and polydispersities (1.49,2.25) were useful for the fabrication of polymer optical devices because of their good solubility in common organic solvent and the processable flexibility. The ratios of the components of the polyesters were characterized by FTIR and NMR. The polyesters had high glass transition temperature (Tg,: up to 170 °C) and good thermal stabilities (Td: up to 470 °C). The refractive index of the polyester film was tuned and controlled in the range of 1.447,1.576 at 1550 nm by monitoring the component fractions during the preparation procedures. Low-loss optical waveguides were fabricated from the resulting polyesters and the propagation loss of the channel waveguides was measured to be around 0.56 dB/cm at 1550 nm. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5923,5931, 2007 [source]

Interaction of Phytochemical-Quercetin with the Other Antioxidant, Ascorbic Acid and their Protective Effect in Tilapia after Ultraviolet Irradiation

Gustavo A. Rodriguez-Montes De Oca
Semi-purified, casein-gelatin-based diets were prepared and supplemented with quercetin (Q) and/ or ascorbic acid (AA): control diet C,Q,(100 mg/kg AA), diet C ,Q+ (100 mg/kg AA + quercetin 10 g/kg), diet C +Q, (1000 mg/kg AA), and diet C +Q+ (1000 mg/kg AA + quercetin 10 g/kg). These diets were fed to tilapia for 19 wk and then fish were divided into controls and ultraviolet (UV) treatments. Fish were exposed to UV radiation. Control groups were protected with a MYLAR® polyester film and plexiglass. At week 20, the same fish were re-exposed to UV radiation. Control groups of fish were protected by a double layer of MYLAR® and the UV groups were exposed with no protection. Before UV exposure, 24 h after, and 7 d after the second treatment, fish liver and skin were dissected for Q and AA analyses. The proportion of oxidized ascorbate was significantly increased in fish from treatments C ,Q, and C ,Q+ . Q concentrations in fish after exposures were negligible in skin, whereas liver concentrations were significantly different among control (34 ± 10 ,g/g) and UV-irradiated fish (11 ± 6 ,g/g), respectively. The interaction between these two dietary antioxidants may change after chronic UV irradiation. [source]

Influence of hydroxyvalerate composition of polyhydroxy butyrate valerate (PHBV) copolymer on bone cell viability and in vitro degradation

Hui Liu
Abstract The objective of this study was to elucidate the role of hydroxyvalerate (HV) composition in polyhydroxy butyrate valerate (PHBV) copolymer film on the degradation of copolymer and osteoblastic cell activity. Degradation was studied by monitoring time-dependent changes in mass and chemical composition of the macroporous films. The mass loss of PHBV film upon 19 weeks of exposure to pH 7.4 phosphate buffer medium was found to range from 2.8% to 9.2% with a strong dependence on the original composition of the copolyester film and morphology. Tapping mode atomic force microscopy (TMAFM) was used to examine the roughness change of polyester films due to exposure to buffer medium. Chemical analysis of the degraded film was carried out using NMR to aid in the interpretation of the mass loss and TMAFM data. The NMR results showed a significant decrease in the mol % of HV content in the degraded PHBV film. Additionally, we established that UMR-106 cell proliferation on macroporous PHBV matrix is minimally enhanced by the HV content of PHBV copolymer. Information provided by this study can be used in the selection of appropriate PHBV copolymer for clinical use where the biopolymer needs to remain physically intact and chemically unchanged during the intended period of biomedical application. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Structural materials underpinning functional materials: teaching old dogs new tricks

William A MacDonald
Abstract ,Structural' polymers are finding new applications underpinning new technology developments based on functional polymers. This paper discusses the use of polyester films as base substrates for flexible electronic applications based on conjugated polymers and low-temperature hydrogenated amorphous silica processing, and discusses the challenges involved in successfully developing substrates ,fit for purpose'. Copyright © 2008 Society of Chemical Industry [source]