Rahmayetty, Rahmayetty
Chemical Engineering Department, Universitas Sultan Ageng Tirtayasa Jl. Jendral Sudirman Km. 03, Cilegon, Provinsi Banten, Indonesia 42435

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Polylactic acid Synthesis via Direct Polycondensation Method Using Candida rugosa Lipase Catalyst Rahmayetty, Rahmayetty; Barleany, Dhena Ria; Suhendi, Endang; Prasetya, Bayu; Andiyani, Tuti
World Chemical Engineering Journal VOLUME 1 NO. 5 DECEMBER 2017
Publisher : Chemical Engineering Department, Engineering Faculty, Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62870/wcej.v1i5.2621

Abstract

Polylactic acid (PLA) is a biodegradable, biocompatible polymer and is produced from renewable natural resources. PLA synthesis through a polycondensation mechanism generally uses a metal catalyst, such as Zn and Sn oxides. The disadvantages of using metal catalysts are the contamination of products produced by the metals used so that unsafe products are used for biomedical applications and food packaging. The purpose of this research is to synthesize the safe PLA used for food packaging and biomedical applications. Polycondensation is done by pretreatment of lactic acid at 120oC for 1 hour. Diluted lactic acid is mixed with Candida rugosa lipise catalyst with a certain concentration (1, 2, 3 and 4% w / w). The mixture was heated at certain temperature (60; 80; 100 and 120oC) and vacuum pressure of 0.1 bar for 72 hours. The highest viscosity and density of PLA in this study was produced at 100oC and using 3% Candida rugosa lipase. The highest viscosity and density of PLA were 2443,9 CSt and 1231,9 mg / l respectively. Candida rugosa lipase concentration does not affect PLA yield at constant polycondensation temperature. PLA yield is affected by temperature. PLA yields at 60, 80, 100 and 120 ° C are 97.98; 97,65; 96.78; 96.13% respectively. The molecule weight of PLA at temperature 100oC for 1436-1482. Lipase concentration does not affect the molecular weight of the PLA.
Effect of Polycondensation Temperature to Oligomer yield and Depolimerisation Side Reaction Rahmayetty, Rahmayetty; Sukirno, Sukirno; Gozan, Misri
World Chemical Engineering Journal VOLUME 2 NO. 1 JUNE 2018
Publisher : Chemical Engineering Department, Engineering Faculty, Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62870/wcej.v2i1.3467

Abstract

Ring-opening polymerization reaction is the best method for producing high molecular weight polymers. The stage of manufacture of PLA from lactic acid through the lactide ring opening reaction is carried out through three stages of the process ie polycondensation, depolymerization and polymerization. The polycondensation stage of lactic acid is the stage of oligomer formation. At the polycondensation stage, the oligomeric molecular weight is determined by the temperature, pressure, type and concentration of the catalyst used. The purpose of this research was to obtain the effect of polycondensation temperature without catalyst on oligomer recovery and side reactions of depolymerization. Polycondensation is done by pretreatment of lactic acid at 120oC for 1 hour. After that, the heating lactic acid at varying temperatures..OLLA yield at polycondensation temperature 150; 180; 200oC for 4 h and gradually (at 150 oC for 2 h and 180oC for 2 h) were 96.33; 85.36; 82.13 and 88.37% respectively. The higher  polycondensation temperature, the intramolecular interactions of the molecule as a side reaction was increasing.