ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY http://dx.doi.org/10.14233/ajchem.2014.17487 INTRODUCTION Liquid rubber compound is a mixture of natural rubber latex with various chemical additives to obtain the final result of vulcanizates with a particular process 1,2 . In the manufacture of rubber goods, liquid rubber is the result before the end of the process to obtain the finished rubber goods. In the process of making liquid rubber or compounding, chemical reaction will occur between polyisoprene of latex rubber with a variety of chemicals that are used to form the three-dimensional cross- linking between the molecules of the rubber material poly- isoprene with vulcanizator such as sulphur that will improve nature of the original rubber to be more usable for manufacture rubber goods 3-6 . Liquid rubber compound chemicals generally consists of vulcanizator, accelerator, antioxidant ingredients, activator, stabilizer and filler as well as other supplemental materials 1,2 . Latex rubber finished products generally have certain traits preferred, therefore, liquid rubber composition to be made tailored to the type of product to be produced or the nature of the preferred. The raw material of liquid rubber compound is concen- trated latex with most additive components solid so that the process of mixing or compounding would be more perfect if it is done by mixing various ingredients such additives in the liquid state is by first dispersing the various ingredients into Effect of KOH as Stabilizer on Mechanical and Chemical Properties of Liquid Rubber Compound TEJA DWI SUTANTO 1,2,* , BAMBANG SETIAJI 3 , KARNA WIJAYA 3 and TOTOK EKA SUHARTO 2 1 Postgraduate student of Chemistry Department, Faculty of Mathematics and Natural Sciences, Gadjah Mada University, Yogyakarta, Indonesia 2 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Bengkulu University, Bengkulu, Indonesia 3 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Gadjah Mada University, Yogyakarta, Indonesia *Corresponding author: Tel: +62 81367722099; E-mail: tejasutanto44@yahoo.com Received: 28 February 2014; Accepted: 20 May 2014; Published online: 1 December 2014; AJC-16363 The effect of KOH stabilizer on mechanical and chemical properties of liquid rubber compound has been examined. Liquid rubber made by mixing stearic acid and zinc oxide as activator, 3,5-di-tert-butyl-4-hydroxy toluene and liquid smoke as antioxidant, CaCO3 as filler, dibenzothiazole disulfide and tetramethyl thiuram disulfide as accelerator, KOH as stabilizer and sulphur as vulcanizing agent with concentrated latex at room temperature, then maturated for 72 h. In this research the use of KOH stabilizer was varied as 3, 4, 5, 6 and 7 phr. Before being examined, rubber film made from liquid rubber compound by dyeing process then vulcanization done at 100 °C with water vapor. The rubber film which produced from liquid rubber compound then was characterized their mechanical and chemical properties such as resistance to heating, resistance to acid and alkaline resistance. The result showed that KOH content changed the mechanical and chemical properties of liquid rubber compound. Keywords: Liquid rubber compound, Stabilizer, Vulcanization, Tensile strength. liquid ingredients with the addition of certain dispersants so expect the resulting liquid rubber specification will be eligible to make a variety of rubber goods 1,7 . The problems that exist in the rubber industry is the unavailability of liquid or compound in large quantities ready to be used to make a variety of rubber goods as new liquid rubber is usually made prior to manufacture certain goods carried, in addition to compound usually made in the form of a dense mix of rubber material that has been frozen, then solid compound is dissolved if it will be made into a particular item 2 . The purpose of this research is to study the effect of varia- tion in the use of KOH as stabilizer in the manufacturing process of liquid rubber compound on their changes of the mechanical and chemical properties which includes the resis- tance to heating or oxidation, resistance to acid and resistance to alkaline. Determination the changes of mechanical and chemical properties done by measuring the tensile strength and elongation at break of rubber films before and after a particular treatment 4,8-10 . EXPERIMENTAL The process of making liquid rubber or rubber compound is the process of mixing the concentrated latex materials with different dispersion additives that have been made in advance. such as stearic acid and zinc oxide as activator, 3,5-di-tertbutyl- Asian Journal of Chemistry; Vol. 26, No. 24 (2014), 8371-8374