Lignan resin composition

The impact resistance by the Izod method shows similar behavior for the resins under study. The same can be said for the deflexion temperature under flexural load except for the unmodified lignan resin composition (Fig. 11],... 

Composition of the lignan resin of Parana pine tree Knots... 

Propolis from Europe is the best known type of propolis. In European regions with temperate climate bees obtain resin mainly from the buds of Poplus species and the main bioactive components are flavonoids (Greenaway et al., 1990). In tropical countries, the botanical resources are much more variable in respect to temperate zones, so bees find much more possibilities of collecting resins and hence the chemical composition of tropical propolis are more variable and distinct from European ones (Sawaya et al., 2011). Different compounds have been reported in tropical propolis such as terpenoids and prenylated derivatives of p-coumaric acids in Brazilian propolis (Marcucci, 1995), lignans in Chilean samples (Valcic et al, 1998), and polyisoprenylated benzophenones in Venezuelan, Brazilian, and Cuban propolis (Cuesta-Rubio et al., 1999 Marcucci, 1995). 

As a general remark, the best set of results is obtained, for each resin, for molding compositions with 100 phr wood-flour field. This preliminary evaluation shows that, taking the phenol-formaldehyde resin as the standard for comparison, the lignan-formaIdehyde resin has about the same characteristics. 

Section three contains six chapters dealing with the noncellu-losic components of plant life including tall oil, wood and gum rosins, lignan, bark extracts, tannin, wood flour, and rice hull flour for use in the preparation of composites, resins, adhesives, and fillers. Filler properties are described in some detail. Substitutes for phenol-formaldehyde resins are described as well as the generation of the industrially important trimellitic anhydride from natural sources. A problem in the rubber elasticity of gutta percha networks is discussed. 

---