Wu Yiqiang

Determination of Chemical Components of Benzene/Ethanol Extractives of Chinese-Fir Wood by GC/MS

The chemical components from benzene/ethanol extractives of fresh Chinese-fir wood were separated and identified by GC/MS after enriched. Relative content of each component was determined by area normalization. 18 compounds representing 94.96% of the extractives were identified. The main and abundant constituents were octadecanoic acid, methyl ester(16.95%), nonadecanoic acid, methyl ester (cas) (15.23%), hexadecanoic acid, methyl ester (cas) (7.12%), hexadecanoic acid, ethyl ester (cas) (6.83%), dibutyl phthalate(6.09%), cholest-5-en-3-ol (3a)- ,carbonochloridate(5.45%), isopropyl myristate(4.52%), hexadecane (cas) (4.31%), benzene (cas) (4.09%), 3,7,11,15- tetramethyl- 2-hexadecen-l-ol(4.01%), tetradecanal (cas) (3.62%), 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (cas) (3.57%), a-cedrene (3.30%), nonadecane(3.14%), 1- tridecanol (2.96%), 1,2-benzenedicarboxylic acid, bis(2- methylpropyl) ester (cas) (2.21%), and so on. The most components of benzene/ethanol extractives of fresh Chinese-fir wood are not only abundant and healthy to human, but also used as bioenergy.

Collapse-type shrinkage characteristics in plantation-grown eucalypts: I. Correlations of basic density and some structural indices with shrinkage and collapse properties

Collapse-type shrinkage is one of highly refractory drying defects in low-medium density plantation-grown eucalypt wood used as solid wood products. Basic density (BD), microfibril angle (MFA), double fibre cell wall thickness (DWT), proportion of ray parenchyma (RP), unit cell wall shrinkage, total shrinkage and residual collapse, which are associated with collapse-type shrinkage characteristics, were investigated by using simple regression method for three species of collapse-susceptibleEucalyptus urophyll,, E. grandis andE. urophylla×E.grandis, planted at Dong-Men Forest Farm in Guangxi autonomous region, China. The results indicated that: unit cell wall shrinkage had a extremely strong positive correlation with BD, moderately strong positive correlation with DWT, and a weakly or moderately negative correlation with RP and MFA; total shrinkage was positively correlated with BD, DWT and RP and negatively related to MFA, but not able to be predicted ideally by any examined factors alone owing to lower R2 value (R2≦0.5712); residual collapse was negatively correlated with BD and DWT, linearly positively correlated with MFA, and had strongly positive linear correlation with RP. It is concluded that BD can be used as single factor (R2≥0.9412) to predicate unit cell wall shrinkage and RP is the relatively sound indicator for predicting residual collapse