| The processabilities of raw natural rubbers from 7 new clones intending to widely plant in the rubber planting areas of Hainan, Yunnan and Guangdong were studied using a rubber process analyzer RPA2000. Processabilities indecies contained consistency coefficient and rheological index, viscoelastic characteristic, stress relaxation time and ageing resistance. The results showed that raw natural rubbers from clones of Yunyan 77-2 and Reken 7-33-97 had good processability and were easy to mix. Raw natural rubbers from Yunyan 77-2 and 77-4 were lower in plasticity retention index (PRI) and poorer in ageing-resistance, whereas raw natural rubber from clone of Zhanshi 93-114 possessed the highest PRI and the best aging resistance. |
