RUBBER DANDELION (TARAXACUM KOK-SAGHYZ) LATEX FILMS: IMPLICATIONS FOR MEDICAL AND LATEX PRODUCT DEVELOPMENT

ABSTRACT NR latex from Taraxacum kok-saghyz Rodin (TK; rubber dandelion), hereafter TNRL, was extracted and purified from 3.5 to 5-month-old greenhouse-grown plants. The extracted TNRL was of high weight average molecular weight (M w ; ∼2000 kg/mol) achieved at a much younger age than the 6 yr needed before Hevea brasiliensis produces rubber above 1000 kg/mol, indicating potential for rubber product manufacturing and fast scale-up potential. TNRL was compounded using a combination of the hypoallergenic chemical accelerators diisopropyl xanthogen polysulfide (DIXP) and zinc diisononyl dithiocarbamate (ZDNC), and recipes varied to optimize mechanical performance. Although limited on latex quantity, a custom apparatus for pouring films was designed to minimize latex use and enable tensile testing. Preliminary drying, leaching, and curing times for TNRL were developed and used for the first time, based on those used for Hevea and guayule ( Parthenium argentatum ). A compound containing 0.6 parts per hundred rubber (phr) ZDNC and 0.4 phr DIXP resulted in cured thin films with 30-MPa tensile strength, 2245% elongation to break, and a modulus at 500% elongation of 1.65 MPa, exceeding the mechanical requirements for surgeons (ASTM Standard D 3577) and examination (ASTM Standard D 3578) gloves. Crosslink density of TNRL films was similar to that of commercial Hevea natural latex films. Using the best-performing film recipe and curing protocol, the world’s first TNRL glove was successfully dipped. This research indicates that TNRL may be suitable for use in low volume, high margin premium latex product markets as latex yields improve, further supporting TK as an alternative rubber industrial crop.