Phenolic resin-based composites

Kumar N M, Reddy G V, Naidu S V, Rani T S and Subha M C S (2009), Mechanical properties of coir/glass fiber phenolic resin based composites , J Reinf Plast Compos, 28, 2605-2613. 

In contrast to expensive synthetic fibers, the use of natural fibers is a very cheap means of reinforcement, especially in countries where these natural products are readily available. Natural fibers, when compared to synthetic fibers, have a lower density and a lower tensile modulus. However, a combination of a sisal fiber with a resole type phenolic resin based on cashew nut shell liquid, a naturally occurring monomer, produces a very cost effective composite with a thermal stability greater than 200°C. The cashew nut shell liquid is a mixture of phenol, 3-(8 -pentadecenyl)phenol, 3-(8 -pentadecenyl)-5-(hydroxy)phenol, 3-(8 -pentadecenyl)-5-(hydroxy) -6-methylphenol, and2-(8-pentadecenyl-6-(hydroxy)benzoicacid [195]. 

Igarashi, A., Terasawa, T., Kanie, M., Yamanohe, T. and Komoto, T. (2005) A morphological study of the effect of carhon nanotuhe filler on trihology of phenol/formaldehyde resin-based composites. Polymer Journal, 37 (7), 522—528. 

At the present time, most of the positive photoresists used in the manufacture of microcircuits consist of a low molecular weight phenolic resin and a photoactive dissolution inhibitor. This composite system is not readily soluble in aqueous base but becomes so upon irradiation with ultraviolet light. When this resist is exposed, the dissolution inhibitor, a diazoketone, undergoes a Wolff rearrangement followed by reaction with ambient water to produce a substituted indene carboxylic acid. This photoinduced transformation of the photoactive compound from a hydrophobic molecule to a hydrophillic carboxylic acid allows the resin to be rapidly dissolved by the developer. (L2,3)... 

Most structural PMCs consist of a relatively soft matrix, such as a thermosetting plastic of polyester, phenolic, or epoxy, sometimes referred to as resin-matrix composites. Some typical polymers used as matrices in PMCs are listed in Table 1.28. The list of metals used in MMCs is much shorter. Aluminum, magnesium, titanium, and iron- and nickel-based alloys are the most common (see Table 1.29). These metals are typically utilized due to their combination of low density and good mechanical properties. Matrix materials for CMCs generally fall into fonr categories glass ceramics like lithium aluminosilicate oxide ceramics like aluminnm oxide (alnmina) and mullite nitride ceramics such as silicon nitride and carbide ceramics such as silicon carbide. 

Fiberboard -for food packaging [FOOD PACKAGING] (Vol 11) -medium-density [WOOD-BASED COMPOSITES AND LAMINATES] (Supplement) -phenolic adhesive [PHENOLIC RESINS] (Vol 18) -sampling standards for [SAMPLING] (Vol 21) -structural [WOOD-BASED COMPOSITES AND LAMINATES] (Supplement)... 

WOOD-BASED COMPOSITES AND LAMINATES] (Supplement) -phenolic adhesive [PHENOLIC RESINS] (Vol 18)... 

The newer open-cell foams, based on polyimides (qv), polybenzimidazoles, polypyrones, polyureas, polyphenylquinoxalines, and phenolic resins (qv), produce less smoke, are more fire resistant and can be used at higher temperatures. These materials are more expensive and used only for special applications including aircraft and marine vessels. Rigid poly (vinyl chloride) (PVC) foams are available in small quantities mainly for use in composite panels and piping applications (see Flame retardants Hrat-rrststantpot.ymf.rs). 

Figure 35. Mechanical properties of carbon/carbon epoxy-resin hybrid composites, compared with the properties of the composite skeletons before resin impregnation (61,62). The composite skeletons were prepared from Sigrafil HM 3 PAN-based fiber, rigidized with a phenolic resin, and densified by four cycles with coal-tar pitch plus sulfur the carbonization temperature was 1000°C. (a) Young s modulus.

A wood-based composite can be defined as a composite material mainly composed of wood elements. These wood elements are usually bonded together by a thermosetting adhesive (wood truss products could also be regarded as wood-based composites, but connected by metal connectors). The commonly used adhesives include urea-based adhesive (such as urea formaldehyde resin), phenolic-based adhesive (including phenol resorcinol adhesives), isocyanate-based adhesive, and adhesives from renewable resources (like soybean, lignin etc). The wood elements in wood composites can be in many different forms such as ... 

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