Redistilled Liquid Smoke from Oil-Palm Shells and Its Application as Natural Rubber Coagulant

Abstract

Abundant oil-palm shells waste which is generated annually as the result of the increasing production of palm oil can be utilized as source of liquid smoke. The acidic property of liquid smoke shows its potency as natural rubber coagulant. The objectives of this study are to redistill liquid smoke at 80, 90, and 100 ºC and also to examine the coagulation property of the RLS as compared to formic acid as a commercial coagulant. During redistillation, two collections of RLS were obtained from each temperature. The first collection was gathered at the first 5 min and the second one was gathered at the next 5 min. Each collection gave 5 L of RLS. The physical properties test showed that the RLS 100 ºC from the second collection was recommended as the natural rubber coagulant. This coagulant produced Wallace plasticity value that met the the Indonesian standard and high plasticity retention index value. The assumption of constituents in RLS which can prevent the storage hardening in rubber was not proven.