Characterization of new latex-timber clones of natural rubber

The clonal origin of the natural rubber tree has influences on the latex yield and properties of raw natural rubber (NR); therefore, study of the breeding of NR in order to select suitable rubber clones is important. With a recent increasing demand in rubberwood, yield of timber becomes a new parameter of interest for selection of the rubber clone. Studies were made on new breeds of rubber clones, identified as the RRIM 2000 series. It was found that the new clonal rubbers have a timber yield 3–5 times higher than those of average existing clones such as the Rubber Research Institute of Malaysia (RRIM) 600, while the latex yield is 3 times higher. The other important processing properties, including the mechanical stability time of the latex, Mooney viscosity, and plasticity retention index of raw rubber, are comparable to those of presently used clones and satisfy well the Standard Malaysian Rubber specification. The findings are important as they imply that the lattices and dry rubber of the new rubber clones could be used to produce rubber products without any difficulty. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1517–1521, 2000