Redwood, Sequoia

Fig. 3.10 Map of Redwood (Sequoia) distribution. The numbers refer to the three chemotypes...

Perhaps the most extensive area of research in simple pretreatment systems to enhance the weathering properties of wood has involved application of inorganic salt solutions. Much of the early work in this field was undertaken at the U.S. Forest Products Laboratory in Madison, Wisconsin and was aimed at improving the performance of transparent finishes. Black [25] described an experimental chromate-based wood finish and Black and Mraz [26] discovered that both acid and ammoniacal-copper chromate treatments significantly improved the performance of clear finishes on western red cedar, redwood (Sequoia sempervirens), and Douglas fir plywood. Later research [27] demon-... 

Dextrorotatory inositol occurs in various plants as its monomethyl ether, pinitol, which was first mentioned by Berthelot as a constituent of the exudate of Pinus lamhertiana Dougl. More recently it has been discovered in the heartwood of the redwood Sequoia sempervirensy and in two varieties of the loco weed, Astragalus earlei and Oxytropis lambertii. 

Eucalyptus regnans is the classic example of a eollapse-prone timber. Once eonsidered suitable only as fuelwood, today it is in demand for flooring, furniture and in other prestige items. Collapse-prone timbers inelude eertain other eucalypts, oak (Quercus sp.), black walnut Juglans nigra), western red eedar Thuja plicata) and redwood Sequoia sempervirens). 

It was pointed out that direct attachment of the D-galactose residues to the hexosan framework is only one possibility. It was observed that the D-galactosidic linkage is quite labile to acids. Polysaccharides of similar composition were isolated from western hemlock and redwood Sequoia sempervirens), and it was suggested that water-soluble galactoglucomannans may be of general occurrence in softwoods. 

The coastal redwood. Sequoia sempervirens, one of the largest trees, lives at one of the lowest population densities. 

American beech (Fagus grandifolia Ehrh) 22 Redwood (Sequoia sempervirens (D.Don Endll.) 33... 

As the relative proportions of the woody components vary only within narrow ranges for common commercial species, the EMCs at a given relative humidity and temperature are closely similar for these woods. However, at high relative humidities deviations from mean values can appear. Shubin s data (1990) show, for instance, that at 95% relative humidity the EMC at 42.4°C ranges from 22% for a pine to 33% for an oak. Hoadley (1980) notes that in species with a high extractives content, such as redwood (Sequoia sempervirens) and mahogany (Swietenia mahogani), the fibers remain saturated at 22%-24% moisture content, whereas birch (Betula spp.) may have a moisture content up to 35% at fiber saturation. 

Wood Species. The following types of conunercial lumber were obtained from Riverside Lumber Company in New Orleans, LA spruce, Picea sp, yellow birch, Betula alleghaniensis Britton, northern red oak, Quercus rubra L. redwood. Sequoia sempervirens (D. Don) mid Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don). 

D-Inositol (d-inositol, jS-inositol, matezodambose), m.p. 247-248 , Hd + 65 (H2O), occurs as a monomethyl ether, pinitol, m.p. 186 , Md + 65.5 (H2O), in many plants, particularly conifers (s). The heartwood of the sugar pine, Pinus lambertiana Dough, averages 4% by weight (range, 1.3-9.5%) of pinitol (9). Other sources are the red spruce Picea rubra) (10), redwood Sequoia sempervirens) (11), and the loco weed (1 ). Pinitol is sweet, very soluble in water, and stable in dilute acids and... 

Kritchevsky G, Anderson A B 1955 The cone solid of coast redwood Sequoia sempervirens) and giant sequoia Sequoia gigantea). J Org Chem 20 1402-1406... 

The lability of several conioids suggests that natural oligomers and polymers may occur. Polymerization of sequirin under acidic conditions results in a material having an infrared spectrum nearly identical with that of the water-soluble polymers ( tannin and phlobaphen ) from redwood (Sequoia sempervirens) (93). Milder acid treatment of sequirin and also of hydroxysugiresinol yields isose-quirin, the structure of which has been postulated mainly on the basis of a mechanism of its formation (93). 

Balogh B, Anderson A B 1965 Chemistry of the genus Sequoia. II. Isolation of sequirins, new phenolic compounds from the coast redwood Sequoia sempervirens). Phytochemistry 4 569-575... 

The disease known as hot-tub dermatitis can be caused by bathing in redwood Sequoia sp.) tubs. The disease is caused by a bacterium Pseudomonas sp.) that enters via hair follicles (180), and it is probably not related in any causal way to the use of redwood. 

Chan-Yeung M, Abboud R 1976 Occupational asthma due to California redwood Sequoia semper-Virens dust. Am Rev Resp Dis 114 1027-1031... 

Wiedemann [130] used samples of redwood Sequoia sempervirens), balsa Ochroma pyramidale/lagopus), quebracho bianco Aspidosperma quebracho-bianco) and beech wood (Fagus spec.) to determine the mechanical properties of wood by means of TMA and DSC. Flexure measurements as depicted in Figure 23 show different, highly reproducible onset temperatures for breakdown in the chosen samples from the very light balsa wood to the very hard South American quebracho bianco and - for comparison - bamboo. TMA together with DSC results indicates that such breakdowns take place only after the complete decomposition of cellulose. 

---