Sintesis dan Karakterisasi Karet Alam Siklis Berat Molekul Rendah Melalui Degradasi Oksidatif (Metode Brosse)

Abstract

The research has done the synthesis and characterization of natural rubber cyclical low molecular weight through oxidative degradation (Method Brosse). Cyclic Liquid Natural Rubber (CLNR) is a cyclical natural rubber that has decreased molecular weight. Synthesis of Cyclic Liquid Natural Rubber (CLNR) can be done in two ways, namely degradation after cyclization and degradation before cyclization. Degradation after cyclization using Cyclic Natural Rubber (CNR), degradation is done with the help of the phenyl hydrazine reagent with oxygen gas atmosphere with a flow rate of 2 LMin for 24 hours. Degradation prior to cyclization using raw materials concentrated latex with a surfactant is Cetyl Trimethyl Ammonium Bromide (CTAB) to prevent latex damaged during the process of oxidative degradation, degradation carried out with the aid of phenylhydrazine reagents with the atmosphere of oxygen gas with a flow rate of 2 LMin for 24 hours, the product is called Liquid Natural Rubber (LNR). Then proceed with the process of cyclization with Lewis acid catalyst POs. Characterization of CNR, LNR and CLNR le analysis of functional groups with Fourier Transform Infra Red (FTIR), testing molecular weight by gel permeation chromatography and Ostwald viscometer, thermal analysis by Differential Scanning Calorimetry (DSC), and solubility test conducted by dissolving the sample with a number of certain solvents. Analysis of functional groups by FTIR absorption band obtained a typical area is the wave number 1675 1500 cm, which strain of CC bonds. Test molecular weight by gel permeation chromatography showed a significant decrease in molecular weight also is 51.567 % on the sample CLNR. At viscosity test using Ostwald viscometer showed a decrease in molecular weight of CLNR 1, LNR and CLNR 2 each amounting to 48.740 %, 29.833% and 26.430 %. In the DSC test information generated glass transition temperature of the CNR, CLNR 1, LNR and CLNR 2, namely 102.80°C, 103.67°C, 105.99 C and 104.24°C. CNR solubility test sample, CLNRI, LNR, and CLNR 2 dissolved in a solvent which has a polarity index of 0.04 to 4.4.