7 - Properties of natural rubbers from guayule and rubber dandelion

Abstract

Alternative sources of natural rubber (NR) besides Hevea brasiliensis are related to the sustainability of our society: Hevea NR is the most indispensable material for heavy-duty tires and about 50,000 other products. However, Hevea rubber tree, which is cultured in rainy tropical regions, has recently experienced biosecurity problems. Meanwhile, the lack of biodiversity of NR has been recognized as potentially disastrous to the global rubber supply. Guayule (Parthenium argentatum) and rubber dandelion (Taraxacum kok-saghyz) have long been known to produce NR and are the most promising plants for the next generation of NR sources among a large number of NR yielding plants. They are much highlighted as possible alternative plants due to their adaption to temperate or even subarctic zones. Until now, there are several reports on guayule and rubber dandelion in different study fields, which support the suitability of both NRs as the alternatives to Hevea NR. This chapter summarized the history of researches on guayule and rubber dandelion including their current situations. In particular, the mechanical characteristics of both guayule and dandelion NRs, and the necessities to be the alternative NRs of H. brasiliensis from the viewpoint of strain-induced crystallization behavior were mainly discussed.