3. Experimental
3.1. Preparation of liquid natural rubber (LNR)
The 500 g of deproteinized natural rubber latex (DPNR) was stabilized by adding appropriated amount of nonionic surfactant and sodium chlorite, with stirring at 50 ºC for 2 h. 100 ml of hydrogen peroxide was then added to the mixture. After few minutes the pH was reduced to a value of 5 by adding small amount of diluted formic acid (20 %). The depolymerization reaction took place at 50 ºC with stirring for 14 days. The appropriate amount of methanol was added to the mixture to precipitate LNR