✦ LIBER ✦

TSC study of secondary dielectric relaxations in a polyepoxy matrix composite

✍ Scribed by M. Fois; A. Lamure; P. Guuinic; C. Lacabanne

Publisher: John Wiley and Sons
Year: 1997
Tongue: English
Weight: 160 KB
Volume: 66
Category: Article
ISSN: 0021-8995
DOI: 10.1002/(sici)1097-4628(19971003)66:1<135::aid-app16>3.0.co;2-0

No coin nor oath required. For personal study only.

✦ Synopsis

Two thermal analysis techniques-Differential Scanning Calorimetry and Thermostimulated Current-have been used to characterize a mica/glass fiber-reinforced composite; the matrix is a novolac epoxy resin. The glass transition temperature of the composite as determined by DSC is 80ЊC. Below the glass transition temperature, two complex relaxation modes g and b, respectively situated at 090 and 040ЊC, have been observed. The analysis of the fine structure shows that they are constituted of elementary processes characterized by relaxation times following compensation laws. Because the compensation temperature corresponding to the g mode is located in the vicinity of the glass transition, it has been assigned to cooperative movements precursors of the glass transition. The mobile units might be the phenyl rings in the bisphenol A. Considering its dependence upon water content, the b mode has been related to the molecular mobility of bound water.

📜 SIMILAR VOLUMES

TSC study of the dielectric relaxations

TSC study of the dielectric relaxations of human-bone collagen

✍ M. Fois; A. Lamure; M. J. Fauran; C. Lacabanne 📂 Article 📅 2000 🏛 John Wiley and Sons 🌐 English ⚖ 147 KB 👁 1 views

Differential scanning calorimetry (DSC) and thermally stimulated current (TSC) were used to characterize human-bone collagen. DSC glass-transition and denaturation temperatures of the collagen in a dehydrated state were 90 and 215 °C, respectively. By TSC, the main relaxation mode, labeled ␣ and loc

Combined dielectric spectroscopy and the

Combined dielectric spectroscopy and thermally stimulated currents studies of the secondary relaxation process in amorphous poly(ethylene terephthalate)

✍ J. Menegotto; P. Demont; A. Bernes; C. Lacabanne 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 208 KB 👁 2 views

The dielectric secondary ␤ relaxation process of poly(ethylene terephthalate) has been investigated by dielectric spectroscopy (DS) and thermally stimulated currents (TSC). To analyze the broad and asymmetric DS spectra, without previous assumptions on the shape and the number of overlapped loss com

A.C. dielectric and TSC studies of const

A.C. dielectric and TSC studies of constrained amorphous motions in flexible polymers including poly(oxymethylene) and miscible blends

✍ Bryan B. Sauer; Peter Avakian; Edmund A. Flexman; Mimi Keating; Benjamin S. Hsia 📂 Article 📅 1997 🏛 John Wiley and Sons 🌐 English ⚖ 319 KB 👁 1 views

Poly(OxyMethylene) (POM) and its miscible blends were studied by multifrequency A.C. dielectric and thermally stimulated currents (TSC). The blends contained small amounts of either poly(vinyl phenol), which is a high glass transition (T g ) diluent, or a styrene-co-hydroxy styrene oligomeric low T

Study of Dielectric Relaxation Processes

Study of Dielectric Relaxation Processes in Poly(p-phenylene sulfide) Using a Thermally Stimulated Discharge Current Technique

✍ Jitendra K. Quamara; Nata Singh; Azad Singh 📂 Article 📅 2001 🏛 John Wiley and Sons 🌐 English ⚖ 119 KB 👁 2 views

Chain-extended bismaleimides. II. A stud

Chain-extended bismaleimides. II. A study of chain-extended bismaleimides as matrix elements in carbon fiber composites

✍ Zekeriya Yerlikaya; N. Kutay Erinç; Zeki Öktem; Erdal Bayramli 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 406 KB 👁 1 views

A series of chain-extended bismaleimide resins as matrix elements in carbon fibers were cured and characterized in terms of their thermal and thermomechanical properties. The cured resins were stable up to 430°C and EDABMI/MDA has the highest Tg value and the lowest loss modulus value. T o understan

A Quantitative Study of in vitro Hepatic

A Quantitative Study of in vitro Hepatic Metabolism of Tacrolimus (FK506) Using Secondary Ion and Matrix-assisted Laser Desorption/Ionization Mass Spectrometry

✍ Arkady I. Gusev; David C. Muddiman; Andrew Proctor; Andrew G. Sharkey; Prasad N. 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 438 KB 👁 1 views

The identification and simultaneous quantification of Tacrolimus and its hepatic metabolites in baboons has been achieved using matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry and static secondary-ion mass spectrometry (TOF-SIMS). Little fragmentation, high