Effect of bio-organic liquid as a rubber coagulant for natural rubber sheets production

Abstract

In this work, coagulating efficiency, physical properties of gum rubber and mechanical
properties of vulcanized rubber were studied by using of 4 types of bio-organic liquids: lemon, kaffir
lime, pineapple and orange. The efficiency and physical properties were compared with those of
formic acid. It was found that bio-organic liquids can be use as an coagulant to produce a rubber
sheet. The suitable ratio of natural latex and bio-organic juices to form one green rubber sheets is 3 L
and 600 mL, respectively, while that of natural latex and 3 % formic acid is 3 L and 270 mL. Four
different types of bio-organic juices showed different acid types and quantities. The bio-organic
liquid prepared from lemon and kaffir lime contains citric acid as a major acid. The coagulant
prepared from pineapple contains two major acids i.e. lactic acid and acetic acid while the coagulant
prepared from orange contains lactic acid as a major acid. In addition, the physical and mechanical
properties of vulcanized rubbers coagulated from bio-organic liquid and formic acid gave no
significant differences in mechanical properties.

Keyword: natural rubber latex, bio-organic liquid, coagulation