Evaluation of Natural Rubber from Clones of Hevea Brasiliensis

Abstract

The latex and natural rubber from rubber trees [Hevea brasiliensis (Willd. exAdr. de Juss.) Muell. Arg.] from clones (RRIM 600, IAN 873, GT 1 and PB 252) recommended to the state of São Paulo, Brazil, were studied in three different tapping systems. The parameters studied were dry rubber content (DRC), percentages of ash and of nitrogen, Wallace Plasticity (P0) and Mooney Viscosity (VR). The rubber properties vary considerably as a function of clone type, tapping method and season of the year. DRC tends to decrease in the beginning of the dry, cold season (May and June), whereas both nitrogen % and ash % increase in the same period. A good linear correlation was obtained for P0 and VR. The highest P0 and VR were obtained for RRIM 600.

Angiogenic properties of natural rubber latex biomembranes and the serum fraction of Hevea brasiliensis

“…large error bars) may have several sources. First, NR does possess different properties depending on the period of collection (seasonal variation) and storage time [24,26,31]. Indeed, an inspection of our results points to differences in the activity for membranes stored for different periods of time.…”

“…The latex composition depends on the season of the year for the extraction and age of the tree [26].…”

Effects of lanthanum complex on the thermo-oxidative aging of natural rubber

“…Because of its unique high elasticity, natural rubber (NR) composites have been widely applied for production of tires and a large number of other industrial products [1]. However, the existence of high level unsaturated isolated double bonds makes NR easily attacked by oxygen [2], especially under conditions of heat, pressure, light, etc.…”

Extensional rheology of raw natural rubber from new clones of Hevea brasiliensis

“…To achieve its self‐sufficiency, Brazil has to expand the planted area and develop new rubber tree clones with high productivity, quality and uniformity, which are the foremost characteristics aimed by industries. Being a natural product, the quality of NR depends, to some extent, on the quantities of nonrubber constituents further than clonal origin, environmental conditions, type of coagulation and self‐life [11–18].…”