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Quasi-carbon/phenolic Composites (phenolic + composite)

Distribution by Scientific Domains

Polymers and Materials Science	100%

Selected Abstracts

Influence of carbon nanotube dispersion on the mechanical properties of phenolic resin composites

POLYMER COMPOSITES, Issue 2 2010
R.B. Mathur
Despite the much touted mechanical properties of carbon nanotubes, composites reinforced with nanotubes have failed to achieve mechanical properties which rival those present in conventional fiber reinforced polymer composites. This article describes an attempt to bridge this gap. Multi-walled carbon nanotubes (MWCNT) were synthesized using a chemical vapor deposition method and were dispersed in phenolic resin by both the wet and dry dispersion techniques before molding into composite bars (50 × 5 × 3 mm3). Although no improvement in the mechanical properties of the MWCNT/phenolic composites was observed over the neat resin value when wet mixing dispersion was employed, an improvement of nearly 158% (160 MPa as compared with 62 MPa for neat resin) was achieved in 5 vol% MWCNT containing phenolic resin prepared by the dry mixing. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers [source]

Effect of quasi-carbonization processing parameters on the mechanical properties of quasi-carbon/phenolic composites

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Donghwan Cho
Abstract In this work, quasi-carbon fabrics were produced by quasi-carbonization processes conducted at and below 1200°C. Stabilized polyacrylonitrile (PAN) fabrics and quasi-carbon fabrics were used as reinforcements of phenolic composites with a 50 wt %/50 wt % ratio of the fabric to the phenolic resin. The effect of the quasi-carbonization process on the flexural properties, interfacial strength, and dynamic mechanical properties of quasi-carbon/phenolic composites was investigated in terms of the flexural strength and modulus, interlaminar shear strength, and storage modulus. The results were also compared with those of a stabilized PAN fabric/phenolic composite. The flexural, interlaminar, and dynamic mechanical results were quite consistent with one another. On the basis of all the results, the quasi-static and dynamic mechanical properties of quasi-carbon/phenolic composites increased with the applied external tension and heat-treatment temperature increasing and with the heating rate decreasing for the quasi-carbonization process. This study shows that control of the processing parameters strongly influences not only the mechanical properties of quasi-carbon/phenolic composites but also the interlaminar shear strength between the fibers and the matrix resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Unmodified and Modified Surface Sisal Fibers as Reinforcement of Phenolic and Lignophenolic Matrices Composites: Thermal Analyses of Fibers and Composites

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 4 2006
Jane Maria Faulstich de Paiva
Abstract Summary: The study and development of polymeric composite materials, especially using lignocellulosic fibers, have received increasing attention. This is interesting from the environmental and economical viewpoints as lignocellulosic fibers are obtained from renewable resources. This work aims to contribute to reduce the dependency on materials from nonrenewable sources, by utilizing natural fibers (sisal) as reinforcing agents and lignin (a polyphenolic macromolecule obtained from lignocellulosic materials) to partially substitute phenol in a phenol-formaldehyde resin. Besides, it was intended to evaluate how modifications applied on sisal fibers influence their properties and those of the composites reinforced with them, mainly thermal properties. Sisal fibers were modified by either (i) mercerization (NaOH 10%), (ii) esterification (succinic anhydride), or (iii) ionized air treatment (discharge current of 5 mA). Composites were made by mould compression, of various sisal fibers in combination with either phenol-formaldehyde or lignin-phenol-formaldehyde resins. Sisal fibers and composites were characterized by thermogravimetry (TG) and DSC to establish their thermal stability. Scanning electron microscopy (SEM) was used to investigate the morphology of unmodified and modified surface sisal fibers as well as the fractured composites surface. Dynamic mechanical thermoanalysis (DMTA) was used to examine the influence of temperature on the composite mechanical properties. The results obtained for sisal fiber-reinforced phenolic and lignophenolic composites showed that the use of lignin as a partial substitute of phenol in phenolic resins in applications different from the traditional ones, as for instance in other than adhesives is feasible. Micrograph of the impact fracture surface of phenolic composite reinforced with mercerized sisal fiber (500 X). [source]