Phenolic-type matrices

Fibers such as sisal (Megiatto Jr. et al., 2009 Ramires et al., 2010a, 2010b), sugarcane bagasse (Hoareau et al., 2006 Trindade et al., 2004), coconut (Barbosa et al., 2010) and curaua (Trindade et al., 2005) have been used as reinforcements of phenolic-type matrices. 

Duolite A-7 2.2 1.12 Phenolic type resin. High porosity and hydrophilic matrix. pH range is 0 to 6. 

From this result on MRS, we expected that a combination of phenolic-resin-based resist and aqueous alkaline developer would lead to etching-type dissolution and non-swelling resist patterns. In this paper, we report on a new non-swelling negative electron beam resist consisting of an epoxy novolac, azide compound and phenolic resin matrix (EAP) and discuss the radiation chemistry of this resist. 

Thermoset composites are made up of thermoset resin-like polyester epoxy and phenol-formaldehyde resin composites with varying fiber volume fractions and fiber length were prepared by following one of the techniques. Among polyester epoxy and phenol-formaldehyde composites, a phenolic-type resin performed as a better matrix than epoxy and polyester resins with respect to tensile and flexural properties due to the high interfacial bonding in phenolic composites [58,59,100]. 

Tannins are considered polyphenols due to the large number of phenolic rings in their structures (Mosiewicki et al., 2007 Moubarik et al., 2009). These natural products can be found in certain plant tissues, such as bark, fruit and wood, and can be removed from these sourees by extraction with water. Tannins are classified in two groups hydrolyzable tannins and condensed tannins (Mueller-Harvey, 2001). The condensed tannins are flavonoids with complex structures (Fig. 2.5). The phenolic groups present in tannin enable this macromolecule to participate in the same reactions as phenol (Tondi and Pizzi, 2009). Condensed tannins are more suitable than the hydrolyzable type for use in the manufacture of a phenolic-type polymeric matrix due to the presence of phenolic rings with a greater number of free positions where the electrophilic attack can occur (Barbosa et al., 2010). The high reactivity of... 

The phenolic-type resins should remain an excellent option for therraoset-matrix composites, with these materials maintaining a prominent position in the area of composites based on their favorable cost/performance characteristics. 

Carbon Composites. Cermet friction materials tend to be heavy, thus making the brake system less energy-efficient. Compared with cermets, carbon (or graphite) is a thermally stable material of low density and reasonably high specific heat. A combination of these properties makes carbon attractive as a brake material and several companies are manufacturing carbon fiber—reinforced carbon-matrix composites, which are used primarily for aircraft brakes and race cars (16). Carbon composites usually consist of three types of carbon carbon in the fibrous form (see Carbon FIBERS), carbon resulting from the controlled pyrolysis of the resin (usually phenolic-based), and carbon from chemical vapor deposition (CVD) filling the pores (16). 

Another type of interaction is represented by hydrophobic interactions between the matrix and some of the components in the hydrolysate. When these interactions occur, the removal of a compound is dependent on the matrix polymer, rather than on the type of the functional groups. The results indicate that styrene- and phenol-based matrices (here represented by Dowex 1x4, Dowex 2x8, IRA 92, and Duolite A7) have an excellent ability to trap phenols, whereas acrylic-based matrices (representedby IRA 67and IRA 458) have poorer ability. Nevertheless, the concentration of phenolic compounds decreased by more than 20% after all treatments. 

---